ylides from glycine pyrazoleamides and allyl bromides were achieved by employing a chiral N,N′-dioxide/MgII complex as the catalyst. This protocol provided a facile and efficient synthesis route to a series of anti-α-amino acid derivatives in good yields with high stereoselectivities. Moreover, a possible catalytic cycle was proposed to illustrate the reaction process and the origin of stereoselectivity
An Isothiourea-Catalyzed Asymmetric [2,3]-Rearrangement of Allylic Ammonium Ylides
作者:Thomas H. West、David S. B. Daniels、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/ja500758n
日期:2014.3.26
Benzotetramisole promotes the catalytic asymmetric [2,,3]-rearrangement of allylic quaternary ammonium salts (either isolated or prepared in situ from p-nitrophenyl bromoacetate and the corresponding allylic amine), generating syn-alpha-amino acid derivatives with excellent diastereo- and enantioselectivity (up to >95:5 dr; up to >99% ee).