Mn(III) salen complexes-catalyzed enantioselective addition of trimethyl silylcyanide to N-benzylimines in the presence of 4-phenyl pyridine-N-oxide as an additive
作者:Noor-ul H. Khan、S. Saravanan、Rukhsana I. Kureshy、Sayed H.R. Abdi、Hari C. Bajaj
DOI:10.1016/j.tetasy.2010.07.003
日期:2010.9
Chiral monomeric and dimeric Mn(III) salen complexes viz., [(S,S)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminato manganese(III) chloride and 5,5-methylene di-[(S,S)-N-(3-tert-butyl salicylidine)-N′-(3′,5′-di-tert-butyl salicylidene)}-1,2-cyclohexanediaminato manganese(III) chloride were used as catalysts for the highly enantioselective Strecker reaction of various imines (derived
手性单体和二聚体Mn(III)赛伦络合物,[[(S,S)-N,N'-双(3,5-二叔丁基水杨基)-1,2-环己烷二氨基氯化锰(III)和5 ,5-亚甲基二[[(S,S)- N-(3-叔丁基水杨基吡啶)-N '-(3',5'-二叔丁基水杨基)}-1,2-环己烷二氨基锰(III)氯化物用作各种亚胺的高对映选择性Strecker反应的催化剂(通过醛和胺的缩合反应)与TMSCN作为甲苯中氰化物的来源。当N达到ee> 99%时,α-氨基腈的优良收率(95%)-(2-甲氧基苄基)-1-苯基甲胺被用作底物,而4-苯基吡啶-N-氧化物(4-PPNO)在-55°C下在28小时内被用作添加剂。发现二聚催化剂比单体催化剂更具反应性和对映选择性。在本研究中使用的手性二聚催化剂在保持其性能的情况下可回收和再循环数次。