Enantioselective [3 + 2]-Cycloadditions Catalyzed by a Protected, Multifunctional Phosphine-Containing α-Amino Acid
作者:Bryan J. Cowen、Scott J. Miller
DOI:10.1021/ja0734243
日期:2007.9.1
Catalytic asymmetric [3 + 2]-cycloadditionreactions between α-allenic esters and enones are presented. We have found that a simple phosphine-containing protected α-amino acid derivative is capable of promoting such cycloadditions in high yields with significant levels of regioselectivity and enantioselectivity. Furthermore, employing chiral racemic γ-substituted allenoates in the cycloaddition with
介绍了 α-丙二烯酯和烯酮之间的催化不对称 [3 + 2]-环加成反应。我们发现,一种简单的含膦受保护的 α-氨基酸衍生物能够以高产率促进此类环加成反应,并具有显着的区域选择性和对映选择性。此外,在与查耳酮底物的环加成反应中使用手性外消旋 γ-取代的烯丙酸酯会导致“去外消旋”反应,以高产率提供高达 93% ee 的环戊烯。