Cp2VCl2-catalyzed meso-selective pinacol coupling reaction of aldimines in the presence of chlorosilane and zinc metal

Journal of Organic Chemistry

Volumn 63, Issue 25, 1998, Pages 9421-9424

  Hatano, Bunpei ^a   Ogawa, Akiya ^a   Hirao, Toshikazu ^a  

^a OSAKA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDE; CARBONYL DERIVATIVE; DIAMINE DERIVATIVE; KETONE; REDUCING AGENT; SOLVENT; ZINC;

ARTICLE; CATALYSIS; CHEMICAL REACTION; DIMERIZATION; ISOMERISM; STEREOCHEMISTRY; TEMPERATURE;

EID: 0032509277     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo981396o     Document Type: Article

References (42)

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23. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
24. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
25. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
26. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
27. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
28. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
29. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
30. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
31. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
32. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
33. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
34. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
35. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
36. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
37. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
38. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
39. For reductive coupling of aldimines using stoichiometric or excess amounts of reductants, see: (a) Natsugari, H.; Whittle, R. R.; Weinreb, S. M. J. Am. Chem. Soc. 1984, 106, 7987. (b) Jung, S. H.; Konh, H. J. Am. Chem. Soc. 1985, 107, 2931 (c) Roskamp, J. E.; Pedersen F. S. J. Am. Chem. Soc. 1987, 109, 3152. (d) Mangeney, P.; Tejero, T.; Alexakis, A.; Grosjean, F.; Normant, J. Synthesis 1988, 255. (e) Betschart, C.; Schmidt, B.; Seebach, D. Helv. Chem. Acta 1988, 71, 1999. (f) Takai, K.; Tsubaki, Y.; Tanaka, S.; Beppu, F.; Fujiwara, Y. Chem. Lett. 1990, 203. (g) Enholm, E. J.; Forbes, D. C.; Holub, D. P. Synth. Commun. 1990, 20, 981. (h) Imamoto, T.; Nishimura, S. Chem. Lett. 1990, 1141. (i) Aurrecoechea, J. M.; Fernández-Acebes, A. Tetrahedron Lett. 1992, 33, 4763. (j) Shono, T.; Kise, N.; Oike, H.; Yoshimoto, M.; Okazaki, E. Tetrahedron Lett. 1992, 33, 5559. (k) Kalyanam, N.; Rao, G. V. Tetrahedron Lett. 1993, 34, 1647. (l) Baruab, B.; Projapati, D.; Sandhu, J. S. Tetrahedron Lett. 1995, 36, 747. (m) Shimizu, M.; Iida, T.; Fujisawa, T. Chem. Lett. 1995, 609. (n) Taniguchi, N.; Uemura, M. Synlett 1997, 51. (o) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron Lett. 1997, 39, 3333. (p) Talukdar, S.; Banerji, A. J. Org. Chem. 1998, 63, 3468. (9) So, J. H.; Park, M. K.; Boudjouk, P. J. Org. Chem. 1988, 53, 587.
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