摘要
Tetrahydrobenzo[5]helicenediol(THB-[5]HDIOL) derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas(LLB) aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS(R)and the phenyl group of the additive, which might result in the high enantioselectivity.
Tetrahydrobenzo[5]helicenediol(THB-[5]HDIOL) derivatives as additives for the efficient prolinecatalyzed asymmetric List-Lerner-Barbas(LLB) aldol reactions of bulky aldehyde substrates was described. It was found that with dibromo-substituted helical diols P-4 a/M-4 a as additives, the prolinecatalyzed LLB aldol reaction of 9-anthraldehyde and acetone gave the product in 83% yield and 99% ee.Transition state models revealed an edge-to-face p-p stacking between the anthracenyl group in TS(R)and the phenyl group of the additive, which might result in the high enantioselectivity.
基金
the National Natural Science Foundation of China (No. 21572233)
the Strategic Priority Research Program of Chinese Academy of Sciences(No. XDB12010400) for financial supports