Effective Activation of the Chiral Salen/Ti(OiPr)4 Catalyst with Achiral PhenolicN-Oxides as Additives in the Enantioselective Cyanosilylation of Ketones
作者:Bin He、Fu-Xue Chen、Yan Li、Xiaoming Feng、Guolin Zhang
DOI:10.1002/ejoc.200400411
日期:2004.11
the asymmetric cyanosilylation of ketones. By using 10 mol % of chiral salen-titanium(IV) complex in combination with 1 mol% achiral phenolic N-oxide as an additive, aromatic, aliphatic and heterocyclic ketones have been converted into the corresponding cyanohydrin trimethylsilyl ethers in 58-96% yields with 56-82% ee. Several factors concerning the reactivity and enantioselectivity have been discussed
已发现手性钛 (IV) 配合物与酚类 N 氧化物添加剂的活化为酮的不对称氰基硅烷化提供了一种替代策略。通过使用 10 mol% 的手性 salen-titanium (IV) 配合物与 1 mol% 的非手性酚 N-氧化物作为添加剂,芳香族、脂肪族和杂环酮以 58-96% 的产率转化为相应的氰醇三甲基甲硅烷基醚含 56-82% ee。已经讨论了有关反应性和对映选择性的几个因素。已经提出了基于实验现象和研究的催化循环来解释这种活化和不对称诱导的起源。