A General Organocatalyst for Direct α-Functionalization of Aldehydes: Stereoselective C−C, C−N, C−F, C−Br, and C−S Bond-Forming Reactions. Scope and Mechanistic Insights
摘要:
The development of a general organocatalyst for the alpha-functionalization of aldehydes, via an enamine intermediate, is presented. Based on optically active alpha,alpha-diarylprolinol silyl ethers, the scope and applications of this catalyst for the stereogenic formation of C-C, C-N, C-F, C-Br, and C-S bonds are outlined. The reactions all proceed in good to high yields and with excellent enantioselectivities. Furthermore, we will present mechanistic insight into the reaction course applying nonlinear effect studies, kinetic resolution, and computational investigations leading to an understanding of the properties of the alpha,alpha-diarylprolinol silyl ether catalysts.
Enantioselective alpha-fluorination of aldehydes using chiral organic catalysts
申请人:MacMillan W.C. David
公开号:US20060189830A1
公开(公告)日:2006-08-24
Nonmetallic, chiral organic catalysts are used to catalyze enantioselective fluorination of enolizable aldehydes. Reaction systems composed of an enolizable aldehyde, an electrophilic fluorination reagent, and a nonmetallic chiral catalyst in the form of an imidazolidinone salt are also provided.
Rapid, General Access to Chiral β-Fluoroamines and β,β-Difluoroamines via Organocatalysis
作者:Olugbeminiyi O. Fadeyi、Craig W. Lindsley
DOI:10.1021/ol802930q
日期:2009.2.19
A rapid, general route to enantiopure beta-fluoroamines and beta,beta-difluoroamines has been developed employing organocatalysis in both a two-pot and a one-pot procedure. Both chemical yields (64-82%) and enantioselectivity (94-98% ee) were excellent and represent a significant improvement in the art of preparing chemically diverse beta-fluoroamines from readily available precursors.