Aryl Bromides as Inexpensive Starting Materials in the Catalytic Enantioselective Arylation of Aryl Aldehydes: The Additive TMEDA Enhances the Enantioselectivity
作者:Yong-Xin Yang、Yue Liu、Lei Zhang、Yan-E Jia、Pei Wang、Fang-Fang Zhuo、Xian-Tao An、Chao-Shan Da
DOI:10.1021/jo502070r
日期:2014.11.7
We used aryl bromides as inexpensive starting materials to enantioselectively arylate aldehydes in one pot. Aryl bromides readily transfer aryls to aryllithiums with n-butyllithium, successively to triarylaluminums with aluminum chloride, and then to aryltitaniums with titanium isopropoxide. Finally aryltitaniums arylate aldehydes catalyzed by (S)-H-8-BINOLTi(Oi-Pr)(2) in excellent yields and enantioselectivities. The additive TMEDA evidently suppresses the racemic background reaction promoted by LiCl generated from salt metathesis. This procedure represents a cost-effective and operationally convenient method for enantioenriched diarylmethanols.
From Aryl Bromides to Enantioenriched Benzylic Alcohols in a Single Flask: Catalytic Asymmetric Arylation of Aldehydes