The first asymmetric [2,3]-sigmatropicrearrangement of achiral allylic amines has been realized by quaternization of the amines with an enantiomerically pure diazaborolidine and subsequent treatment with Et3N. The resultant homoallylic amines were obtained in good yields and excellent ee's. The observed diastereo- and enantioselectivities were rationalized by invoking a kinetically controlled process
Asymmetric [2,3]-Sigmatropic Rearrangement of Allylic Ammonium Ylides
作者:Jan Blid、Olaf Panknin、Peter Somfai
DOI:10.1021/ja0510562
日期:2005.7.1
An asymmetric Lewis acid-mediated [2,3]-sigmatropicrearrangement of allylic amines has been developed, affording the corresponding homoallylic amines in good yield and excellent enantioselectivities. The rearrangement proceeds by complexation of the chiral Lewis acid to the amine followed by deprotonation and rearrangement.