General and practical catalytic enantioselective Strecker reaction of ketoimines: Significant improvement through catalyst tuning by protic additives

Tetrahedron Letters

Volumn 45, Issue 15, 2004, Pages 3147-3151

  Kato, Nobuki ^a   Suzuki, Masato ^a   Kanai, Motomu ^a   Shibasaki, Masakatsu ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

Additive effect; Asymmetric catalysis; Disubstituted amino acids; Ketoimines; Strecker reaction

Indexed keywords

IMINE; SORBINIL;

ARTICLE; CATALYSIS; CATALYST; DIABETIC NEUROPATHY; DRUG SYNTHESIS; ENANTIOSELECTIVITY; LIGAND BINDING; STRECKER SYNTHESIS;

EID: 1642264109     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2004.02.082     Document Type: Article

References (15)

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8. Sarges R., Howard H.R., Kelbaugh P.R. J. Org. Chem. 47:1982;4081. and references cited therein.
9. For beneficial additive effects of the proton source on catalytic enantioselective Strecker reaction of aldoimines, see: Krueger C.A., Kuntz K.W., Dzierba C.D., Wirschun W.G., Gleason J.D., Snapper M.L., Hoveyda A.H. J. Am. Chem. Soc. 121:1999;4284.
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11. Takamura M., Hamashima Y., Usuda H., Kanai M., Shibasaki M. Angew. Chem., Int. Ed. 39:2000;1650. In these cases, protic additives do not change the active catalyst structure. The enantioselectivity was not affected by the protic additives.
12. The possibility that HCN generated from TMSCN and the additive acts as the catalyst modulator can not be denied.
13. Yabu K., Masumoto S., Yamasaki S., Hamashima Y., Kanai M., Du W., Curran D.P., Shibasaki M. J. Am. Chem. Soc. 123:2001;9908.
14. tBuOH (10 equiv) also gave the same peak corresponding to 5, however with lower intensity than when DMP was added.
15. For examples of beneficial effects of protic additives on catalyst structures, see: Yamashita Y., Ishitani H., Shimizu H., Kobayashi S. J. Am. Chem. Soc. 124:2002;3292. and references cited therein.