Enantioselective radical-mediated allylation of α-iododihydrocoumarins using Lewis acids generated from chiral sulfonamides

Tetrahedron Asymmetry

Volumn 9, Issue 12, 1998, Pages 2087-2092

  Murakata, Masatoshi ^a   Jono, Toshiaki ^a   Hoshino, Osamu ^a  

^a TOKYO UNIVERSITY OF SCIENCE   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALPHA IODODIHYDROCOUMARIN; SULFONAMIDE; UNCLASSIFIED DRUG;

ARTICLE; CHIRALITY; COLUMN CHROMATOGRAPHY; ENANTIOMER; LIGAND BINDING; NUCLEAR MAGNETIC RESONANCE; PRIORITY JOURNAL; STOICHIOMETRY; SYNTHESIS;

EID: 0032546889     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0957-4166(98)00212-2     Document Type: Article

References (23)

1. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
2. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
3. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
4. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
5. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
6. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
7. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
8. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
9. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
10. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
11. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
12. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
13. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
14. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
15. For enantioselective radical reactions by employing chiral Lewis acids and organotin reagents, see: (a) Murakata, M.; Tsutsui, H.; Hoshino, O. J. Chem. Soc., Chem. Commun. 1995, 481-482. (b) Urabe, H.; Yamashita, K.; Suzuki, K.; Kobayashi, K.; Sato, F. J. Org. Chem. 1995, 60, 3576-3577. (c) Wu, J. H.; Radinov, R.; Porter, N. A. J. Am. Chem. Soc. 1995, 117, 11029-11030. (d) Nishida, M.; Hayashi, H.; Nishida, A.; Kawahara, N. Chem. Commun. 1996, 579-580. (e) Sibi, M. P.; Ji, J.; Wu, J. H.; Gürtler, S.; Porter, N. A. J. Am. Chem. Soc. 1996, 118, 9200-9201. (f) Wu, J. H.; Zhang, G.; Porter, N. A. Tetrahedron Lett. 1997, 38, 2067-2070. (g) Fhal, A.-R.; Renaud, P. Tetrahedron Lett. 1997, 38, 2661-2664. (h) Sibi, M. P.; Ji, J. J. Org. Chem. 1997, 62, 3800-3801. (i) Sibi, M. P.; Shay, J. J.; Ji, J. Tetrahedron Lett. 1997, 38, 5955-5958. (j) Porter, N. A.; Wu, J. H.; Zhang, G.; Reed, A. D. J. Org. Chem. 1997, 62, 6702-6703. (k) Murakata, M.; Jono, T.; Mizuno, Y.; Hoshino, O. J. Am. Chem. Soc. 1997, 119, 11713-11714. For other developments of enantio selective radical reactions, see: Ref. (j). (l) Nanni, D.; Curran, D. P. Tetrahedron: Asymmetry 1996, 7, 2417-2422. (m) Haque, M. B.; Roberts, B. P. Tetrahedron Lett. 1996, 37, 9123-9126. (n) Blumenstein, M.; Schwarzkopf, K.; Metzger, J. O. Angew. Chem. Int. Ed. Engl. 1997, 36, 235-236; Schwarzkopf, K.; Blumenstein, M.; Hayen, A.; Metzger, J. O. Eur. J. Org. Chem. 1998, 177-181 and references cited therein.
16. For reviews on the creation of quaternary carbon centers, see: (a) Martin, S. F. Tetrahedron 1980, 36, 419-460. (b) Tomioka, K.; Koga, K. J. Synth. Org. Chem. Jpn 1986, 44, 545-557. (c) Fuji, K. Chem. Rev. 1993, 93, 2037-2066 and references cited therein.
17. For reviews on the creation of quaternary carbon centers, see: (a) Martin, S. F. Tetrahedron 1980, 36, 419-460. (b) Tomioka, K.; Koga, K. J. Synth. Org. Chem. Jpn 1986, 44, 545-557. (c) Fuji, K. Chem. Rev. 1993, 93, 2037-2066 and references cited therein.
18. For reviews on the creation of quaternary carbon centers, see: (a) Martin, S. F. Tetrahedron 1980, 36, 419-460. (b) Tomioka, K.; Koga, K. J. Synth. Org. Chem. Jpn 1986, 44, 545-557. (c) Fuji, K. Chem. Rev. 1993, 93, 2037-2066 and references cited therein.
19. The preparation of 3a and asymmetric reactions using the chiral Lewis acid generated from 3 have been reported; see: (a) Corey, E. J.; Lee, D.-H.; Sarshar, S. Tetrahedron: Asymmetry 1995, 6, 3-6. (b) Corey, E. J.; Imwinkelried, R.; Pikul, S.; Xiang, Y. B. J. Am. Chem. Soc. 1989, 111, 5493-5495. (c) Corey, E. J.; Sarshar, S. J. Am. Chem. Soc. 1992, 114, 7938-7939 and references cited therein. (d) Asymmetric aldol reactions using a lanthanoid complex prepared from 3 have recently been reported; see: Uotsu, K.; Sasai, H.; Shibasaki, M. Tetrahedron: Asymmetry 1995, 6, 71-74.
20. The preparation of 3a and asymmetric reactions using the chiral Lewis acid generated from 3 have been reported; see: (a) Corey, E. J.; Lee, D.-H.; Sarshar, S. Tetrahedron: Asymmetry 1995, 6, 3-6. (b) Corey, E. J.; Imwinkelried, R.; Pikul, S.; Xiang, Y. B. J. Am. Chem. Soc. 1989, 111, 5493-5495. (c) Corey, E. J.; Sarshar, S. J. Am. Chem. Soc. 1992, 114, 7938-7939 and references cited therein. (d) Asymmetric aldol reactions using a lanthanoid complex prepared from 3 have recently been reported; see: Uotsu, K.; Sasai, H.; Shibasaki, M. Tetrahedron: Asymmetry 1995, 6, 71-74.
21. The preparation of 3a and asymmetric reactions using the chiral Lewis acid generated from 3 have been reported; see: (a) Corey, E. J.; Lee, D.-H.; Sarshar, S. Tetrahedron: Asymmetry 1995, 6, 3-6. (b) Corey, E. J.; Imwinkelried, R.; Pikul, S.; Xiang, Y. B. J. Am. Chem. Soc. 1989, 111, 5493-5495. (c) Corey, E. J.; Sarshar, S. J. Am. Chem. Soc. 1992, 114, 7938-7939 and references cited therein. (d) Asymmetric aldol reactions using a lanthanoid complex prepared from 3 have recently been reported; see: Uotsu, K.; Sasai, H.; Shibasaki, M. Tetrahedron: Asymmetry 1995, 6, 71-74.
22. The preparation of 3a and asymmetric reactions using the chiral Lewis acid generated from 3 have been reported; see: (a) Corey, E. J.; Lee, D.-H.; Sarshar, S. Tetrahedron: Asymmetry 1995, 6, 3-6. (b) Corey, E. J.; Imwinkelried, R.; Pikul, S.; Xiang, Y. B. J. Am. Chem. Soc. 1989, 111, 5493-5495. (c) Corey, E. J.; Sarshar, S. J. Am. Chem. Soc. 1992, 114, 7938-7939 and references cited therein. (d) Asymmetric aldol reactions using a lanthanoid complex prepared from 3 have recently been reported; see: Uotsu, K.; Sasai, H.; Shibasaki, M. Tetrahedron: Asymmetry 1995, 6, 71-74.
23. A chiral sulfonamide 3b was reported in the asymmetric [2+2] cycloaddition of ketene with aldehyde; see: Tamai, Y.; Yoshiwara, H.; Someya, M.; Fukumoto, J.; Miyano, S. J. Chem. Soc., Chem. Commun. 1994, 2281.