Asymmetric addition of trimethylsilylcyanide to N-benzylimines catalyzed by recyclable chiral dimeric V(V) salen complex
摘要:
Chiral dimeric vanadium (V) salen complex (10 mol%) derived from 5,5-Methylene di-[(S,S)-{N-(3-tert-butyl salicylidine)-N'-(3',5'-di-tert-butyl salicylidene)]-1,2-cyclohexanediamine] with vanadyl suphate followed by auto oxidation was used as efficient catalyst for enantioselective Strecker reaction of N-benzylimines with TMSCN at -30 degrees C. Excellent yield (92%) of alpha-aminonitrile and high chiral induction was achieved (ee up to 94%) in case of 2-methoxy substituted N-benzylimines in 10 h. The catalytic system worked well up to four cycles with retention of enantioselectivity. (C) 2010 Published by Elsevier B. V.
作者:Antony J. Davies、Michael S. Ashwood、Ian F. Cottrell
DOI:10.1080/00397910008087127
日期:2000.3
Abstract A convenient scaleable process for the preparation of substituted phenylglycines 2 by a modified Strecker reaction is described. Bisulfite-mediated addition of benzylamine and cyanide anion to substituted benzaldehydes 3 gave the aminonitriles 4 which were hydrolysed in two steps to the N-protected amino acid 1. Debenzylation using catalytic transfer hydrogenation gave the title compounds
Asymmetric addition of trimethylsilylcyanide to N-benzylimines catalyzed by recyclable chiral dimeric V(V) salen complex
作者:Noor-ul H. Khan、S. Saravanan、Rukhsana I. Kureshy、Sayed H.R. Abdi、Arghya Sadhukhan、Hari C. Bajaj
DOI:10.1016/j.jorganchem.2010.01.018
日期:2010.4
Chiral dimeric vanadium (V) salen complex (10 mol%) derived from 5,5-Methylene di-[(S,S)-N-(3-tert-butyl salicylidine)-N'-(3',5'-di-tert-butyl salicylidene)]-1,2-cyclohexanediamine] with vanadyl suphate followed by auto oxidation was used as efficient catalyst for enantioselective Strecker reaction of N-benzylimines with TMSCN at -30 degrees C. Excellent yield (92%) of alpha-aminonitrile and high chiral induction was achieved (ee up to 94%) in case of 2-methoxy substituted N-benzylimines in 10 h. The catalytic system worked well up to four cycles with retention of enantioselectivity. (C) 2010 Published by Elsevier B. V.