Salicylaldehyde Schiff bases derived from 2-ferrocenyl-2-amino alcohols. Part 1: New chiral ligands for the titanium-catalyzed enantioselective cyanation of aldehydes
作者:Rosa Ma Moreno、Malgorzata Rosol、Albert Moyano
DOI:10.1016/j.tetasy.2006.03.016
日期:2006.4
The condensation of a set of diversely substituted (S)-2-amino-2-ferrocenyl ethanol derivatives 1a–e with the salicylaldehydes 5A–C resulted in the generation of a small library of new chiral Schiff base-ligands, whose titanium isopropoxide complexes have been tested as catalysts in the asymmetric addition of trimethylsilyl cyanide to aldehydes. The enantioselectivity of the reaction is strongly influenced
一组不同取代的(S)-2-氨基-2-二茂铁基乙醇衍生物1a - e与水杨醛5A - C的缩合导致生成了一个小的新手性席夫碱-配体文库,该化合物的异丙醇钛配合物已经测试了将三甲基甲硅烷基氰化物不对称加成到醛中作为催化剂。(a)2-氨基-2-二茂铁基乙醇部分的取代方式和(b)C 3'的性质强烈影响反应的对映选择性水杨醛中的取代基。中间过渡态配合物(基于席夫碱,苯甲醛,异丙醇和氰化物键合到钛上)的计算模型表明,可以通过仔细分析2-氨基乙醇和水杨醛部分之间的空间相互作用来容纳实验结果。金属配位的醛。