Highly enantio- and diastereoselective hetero-Diels-Alder reactions catalyzed by new chiral tridentate chromium(III) catalysts

Angewandte Chemie - International Edition

Volumn 38, Issue 16, 1999, Pages 2398-2400

  Dossetter, Alexander G ^a   Jamison, Timothy F ^a   Jacobsen, Eric N ^a  

^a HARVARD UNIVERSITY   (United States)

Author keywords

Asymmetric catalysis; Chromium; Cycloadditions; Diels Alder reactions; Heterocycles

Indexed keywords

CHROMIUM;

ARTICLE; CATALYST; CHIRALITY; DRUG SYNTHESIS; ENANTIOMER; REACTION ANALYSIS; SIALYLATION; STEREOCHEMISTRY;

EID: 0033549737     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/(SICI)1521-3773(19990816)38:16<2398::AID-ANIE2398>3.0.CO;2-E     Document Type: Article

References (51)

1. For general references on the HDA reaction, see: a) S. J. Danishefsky, Chemtracts: Org. Chem. 1989, 273-297; b) S. J. Danishefsky, Aldrichimica Acta 1986, 19, 59-69; c) D. L. Boger in Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M. Trost, I. Fleming), Pergamon, New York, 1991, pp. 451-512; d) D. L. Boger, S. M. Weinreb, Hetero Diels - Alder Methodology in Organic Synthesis, Academic Press, San Diego, 1987; d) H. Waldmann, Synthesis, 1994, 535-551.
2. For general references on the HDA reaction, see: a) S. J. Danishefsky, Chemtracts: Org. Chem. 1989, 273-297; b) S. J. Danishefsky, Aldrichimica Acta 1986, 19, 59-69; c) D. L. Boger in Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M. Trost, I. Fleming), Pergamon, New York, 1991, pp. 451-512; d) D. L. Boger, S. M. Weinreb, Hetero Diels - Alder Methodology in Organic Synthesis, Academic Press, San Diego, 1987; d) H. Waldmann, Synthesis, 1994, 535-551.
3. For general references on the HDA reaction, see: a) S. J. Danishefsky, Chemtracts: Org. Chem. 1989, 273-297; b) S. J. Danishefsky, Aldrichimica Acta 1986, 19, 59-69; c) D. L. Boger in Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M. Trost, I. Fleming), Pergamon, New York, 1991, pp. 451-512; d) D. L. Boger, S. M. Weinreb, Hetero Diels - Alder Methodology in Organic Synthesis, Academic Press, San Diego, 1987; d) H. Waldmann, Synthesis, 1994, 535-551.
4. For general references on the HDA reaction, see: a) S. J. Danishefsky, Chemtracts: Org. Chem. 1989, 273-297; b) S. J. Danishefsky, Aldrichimica Acta 1986, 19, 59-69; c) D. L. Boger in Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M. Trost, I. Fleming), Pergamon, New York, 1991, pp. 451-512; d) D. L. Boger, S. M. Weinreb, Hetero Diels - Alder Methodology in Organic Synthesis, Academic Press, San Diego, 1987; d) H. Waldmann, Synthesis, 1994, 535-551.
5. For general references on the HDA reaction, see: a) S. J. Danishefsky, Chemtracts: Org. Chem. 1989, 273-297; b) S. J. Danishefsky, Aldrichimica Acta 1986, 19, 59-69; c) D. L. Boger in Comprehensive Organic Synthesis, Vol. 5 (Eds.: B. M. Trost, I. Fleming), Pergamon, New York, 1991, pp. 451-512; d) D. L. Boger, S. M. Weinreb, Hetero Diels - Alder Methodology in Organic Synthesis, Academic Press, San Diego, 1987; d) H. Waldmann, Synthesis, 1994, 535-551.
6. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
7. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
8. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
9. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
10. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
11. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
12. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
13. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
14. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
15. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
16. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
17. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
18. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
19. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
20. For asymmetric catalytic HDA reactions involving Danishefsky's diene and its analogues, see: a) M. D. Bednarski, C. Maring, S. J. Danishefsky, J. Am. Chem. Soc. 1983, 105, 6968-6969; b) K. Maruoka, T. Itoh, T. Shirasaka, H. Yamamoto, J. Am. Chem. Soc. 1988, 110, 310-312; c) E. J. Corey, C. L. Cywin, T. D. Roper, Tetrahedron Lett. 1992, 33, 6907-6910; d) Q. Gao, T. Maruyama, M. Mouri, H. Yamamoto, J. Org. Chem. 1992, 57, 1951-1952; e) Y. Motoyama, K. Mikami, Chem. Commun. 1994, 1563-1564; f) G. E. Keck, X. Y. Li, D. Krishnamurthy, J. Org. Chem. 1995, 60, 5998-5999; g) Y. Motoyama, M. Terada, K. Mikami, Synlett 1995, 967-968; h) K. Mikami, O. Kotera, Y. Motoyama, H. Sakaguchi, Synlett 1995, 975-977; i) A. K. Ghosh, P. Mathivanan, J. Cappiello, Tetrahedron Lett. 1997, 38, 2427-2430; j) S. Matsukawa, K. Mikami, Tetrahedron: Asymmetry 1997, 8, 815-816; k) T. Hanamoto, H. Furuno, Y Sugimoto, J. Inanaga, Synlett 1997, 79-80; l) S. E. Schaus, J. Brånalt, E. N. Jacobsen, J. Org. Chem. 1998, 63, 403-405; m) S. Kobayashi, H. Komiyama, T. Ishitani, Angew. Chem. 1998, 110, 1026-1028; Angew. Chem. Int. Ed. 1998, 37, 979-981; n) L.-S. Li, Y. Wu, Y.-J. Hu, L.-J. Xia, Y.-L. Wu, Tetrahedron: Asymmetry 1998, 9, 2271-2277.
21. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
22. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
23. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
24. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
25. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
26. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
27. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
28. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
29. For asymmetric catalytic HDA reactions involving glyoxylate, pyruvate, or quinone derivatives as dienophiles, see: a) M. Terada, K. Mikami, T. Nakai, Tetrahedron Lett. 1991, 32, 935-938; b) K. Mikami, M. Terada, Y. Motoyama, T. Nakai, Tetrahedron: Asymmetry 1991, 2, 643-646; c) T. A. Engler, M. A. Letavic, M. A., F. Takusagawa, Tetrahedron Lett. 1992, 33, 6731-6734; d) K. Mikami, Y. Motoyama, M. Terada, J. Am. Chem. Soc. 1994, 116, 2812-2820; e) M. Johannsen, K. A. Jørgensen, Tetrahedron 1996, 52, 7321-7328; f) M. Johannsen, S. Yao, K. A. Jørgensen, Chem. Commun. 1997, 2169-2170; g) A. Graven, M. Johannsen, K. A. Jørgensen, Chem. Commun. 1996, 2373-2374; h) S. Yao, M. Johannsen, H. Audrain, R. G. Hazell, K. A. Jørgensen, J. Am. Chem. Soc. 1998, 120, 8599-8605; i) M. Johannsen, K. A. Jørgensen, X.-F. Zheng; Q.-S. Hu; L. Pu, J. Org. Chem, 1999, 64, 299-301.
30. Examples of asymmetric catalytic inverse demand hetero-Diels -Alder reactions have been disclosed recently: a) D. A. Evans, J. S. Johnson, J. Am. Chem. Soc. 1998, 120, 4895-4896; b) J. Thorhauge, M. Johannsen, K. A. Jørgensen, Angew. Chem. 1998, 110, 2543-2546; Angew. Chem. Int. Ed. 1998, 37, 2404-2406; c) D. A. Evans, E. J. Olhava, J. S. Johnson, J. M. Janey, Angew. Chem. 1998, 110, 3554-3557; Angew. Chem. Int. Ed. 1998, 37, 3372-3375.
31. Examples of asymmetric catalytic inverse demand hetero-Diels - Alder reactions have been disclosed recently: a) D. A. Evans, J. S. Johnson, J. Am. Chem. Soc. 1998, 120, 4895-4896; b) J. Thorhauge, M. Johannsen, K. A. Jørgensen, Angew. Chem. 1998, 110, 2543-2546; Angew. Chem. Int. Ed. 1998, 37, 2404-2406; c) D. A. Evans, E. J. Olhava, J. S. Johnson, J. M. Janey, Angew. Chem. 1998, 110, 3554-3557; Angew. Chem. Int. Ed. 1998, 37, 3372-3375.
32. Examples of asymmetric catalytic inverse demand hetero-Diels - Alder reactions have been disclosed recently: a) D. A. Evans, J. S. Johnson, J. Am. Chem. Soc. 1998, 120, 4895-4896; b) J. Thorhauge, M. Johannsen, K. A. Jørgensen, Angew. Chem. 1998, 110, 2543-2546; Angew. Chem. Int. Ed. 1998, 37, 2404-2406; c) D. A. Evans, E. J. Olhava, J. S. Johnson, J. M. Janey, Angew. Chem. 1998, 110, 3554-3557; Angew. Chem. Int. Ed. 1998, 37, 3372-3375.
33. Examples of asymmetric catalytic inverse demand hetero-Diels - Alder reactions have been disclosed recently: a) D. A. Evans, J. S. Johnson, J. Am. Chem. Soc. 1998, 120, 4895-4896; b) J. Thorhauge, M. Johannsen, K. A. Jørgensen, Angew. Chem. 1998, 110, 2543-2546; Angew. Chem. Int. Ed. 1998, 37, 2404-2406; c) D. A. Evans, E. J. Olhava, J. S. Johnson, J. M. Janey, Angew. Chem. 1998, 110, 3554-3557; Angew. Chem. Int. Ed. 1998, 37, 3372-3375.
34. Examples of asymmetric catalytic inverse demand hetero-Diels - Alder reactions have been disclosed recently: a) D. A. Evans, J. S. Johnson, J. Am. Chem. Soc. 1998, 120, 4895-4896; b) J. Thorhauge, M. Johannsen, K. A. Jørgensen, Angew. Chem. 1998, 110, 2543-2546; Angew. Chem. Int. Ed. 1998, 37, 2404-2406; c) D. A. Evans, E. J. Olhava, J. S. Johnson, J. M. Janey, Angew. Chem. 1998, 110, 3554-3557; Angew. Chem. Int. Ed. 1998, 37, 3372-3375.
35. Experimental procedures and analytical data, including ee analysis and determination of relative and absolute stereochemistry where appropriate are included in the Supporting Information.
36. [21] (sale-n = bis(salicylidene)ethylenediamine) provided tetrahydropyrans 6a and 6b in 70 - 82% ee and 24 - 40% ee, respectively, and > 95% de, but with significantly slower reaction rates. However, these results served as a valuable lead into this area.
37. a) G. Casiraghi, G. Casnati, G. Puglia, G. Sartori, G. Terenghi, J. Chem. Soc. Perkin Trans 1. 1980, 1862-1865;
38. b) W. Zhang, E. N. Jacobsen, J. Org. Chem. 1991, 56, 2296-2298.
39. Both enantiomers are available commercially (Aldrich). a) J. F. Larrow, E. Roberts, T. R. Verhoeven, K. M. Ryan, C. H. Senanayake, P. J. Reider, E. N. Jacobsen, Organic Synth. 1999, 76, 46-56; for reviews on the use of cis-1-amino-2-indanol in asymmetric synthesis, see: b) C. H. Senanayake, Aldrichimica Acta 1998, 31, 3-15; c) A. K. Ghosh, S. Fidanze, C. H. Senanayake, Synthesis, 1998, 937-961.
40. Both enantiomers are available commercially (Aldrich). a) J. F. Larrow, E. Roberts, T. R. Verhoeven, K. M. Ryan, C. H. Senanayake, P. J. Reider, E. N. Jacobsen, Organic Synth. 1999, 76, 46-56; for reviews on the use of cis-1-amino-2-indanol in asymmetric synthesis, see: b) C. H. Senanayake, Aldrichimica Acta 1998, 31, 3-15; c) A. K. Ghosh, S. Fidanze, C. H. Senanayake, Synthesis, 1998, 937-961.
41. Both enantiomers are available commercially (Aldrich). a) J. F. Larrow, E. Roberts, T. R. Verhoeven, K. M. Ryan, C. H. Senanayake, P. J. Reider, E. N. Jacobsen, Organic Synth. 1999, 76, 46-56; for reviews on the use of cis-1-amino-2-indanol in asymmetric synthesis, see: b) C. H. Senanayake, Aldrichimica Acta 1998, 31, 3-15; c) A. K. Ghosh, S. Fidanze, C. H. Senanayake, Synthesis, 1998, 937-961.
42. Analysis by low-resolution FAB mass spectrometry and IR spectroscopy indicates that 3a exists as a mixture of oligomeric species with water molecules occupying available coordination sites (see Supporting Information).
43. See Supporting Information for details. Whereas chromium(III) chloride catalyst 3a shows no evidence of decomposition when stored in a desiccator for several months, the hexafluoroantimonate catalyst 3b has a shelf life of approximately two weeks under these conditions. Reactions performed by using older batches of 3b were noticeably slower.
44. .. has been shown to have significant beneficial effects in other asymmetric catalytic systems. D. A. Evans, J. A. Murry, P. von Matt, R. D. Norcross, S. J. Miller, Angew. Chem. 1995, 107, 864-866; Angew. Chem. Int. Ed. Engl. 1995, 34, 798-800.
45. .. has been shown to have significant beneficial effects in other asymmetric catalytic systems. D. A. Evans, J. A. Murry, P. von Matt, R. D. Norcross, S. J. Miller, Angew. Chem. 1995, 107, 864-866; Angew. Chem. Int. Ed. Engl. 1995, 34, 798-800.
46. 2 had a detrimental effect on the enantioselectivity of the reaction.
47. For example, the reaction listed in entry 5, Table 1, when performed in the absence of 4 Å MS, gave the THP 6b in 73 % conversion and 94 % ee after 40 h at room temperature.
48. Use of the catalyst 3b for this reaction resulted in polymerization of the diene. The enantioselectivity was determined chiral GC analysis of lactone 15, prepared by PDC/ AcOH oxidation of methoxyacetal 14.
49. For example, a) callystatin A (isolation): M. Kobayashi, K. Higuchi, N. Murakami, H. Tajima, S. Aoki, Tetrahedron Lett. 1997, 38, 2859-2862; b) (synthesis): M. T. Crimmins, B. W. King, J. Am. Chem. Soc. 1998, 120, 9084-9085; c) Fostriecin A: D. L. Boger, M. Hikota, B. M. Lewis, J. Org. Chem. 1997, 62, 1748-1753, and references therein.
50. For example, a) callystatin A (isolation): M. Kobayashi, K. Higuchi, N. Murakami, H. Tajima, S. Aoki, Tetrahedron Lett. 1997, 38, 2859-2862; b) (synthesis): M. T. Crimmins, B. W. King, J. Am. Chem. Soc. 1998, 120, 9084-9085; c) Fostriecin A: D. L. Boger, M. Hikota, B. M. Lewis, J. Org. Chem. 1997, 62, 1748-1753, and references therein.
51. For example, a) callystatin A (isolation): M. Kobayashi, K. Higuchi, N. Murakami, H. Tajima, S. Aoki, Tetrahedron Lett. 1997, 38, 2859-2862; b) (synthesis): M. T. Crimmins, B. W. King, J. Am. Chem. Soc. 1998, 120, 9084-9085; c) Fostriecin A: D. L. Boger, M. Hikota, B. M. Lewis, J. Org. Chem. 1997, 62, 1748-1753, and references therein.