Predictable and Regioselective Insertion of Internal Unsymmetrical Alkynes in Rhodium-Catalyzed Cycloadditions with Alkenyl Isocyanates
作者:Rebecca Keller Friedman、Tomislav Rovis
DOI:10.1021/ja903899c
日期:2009.8.5
A regioselective, rhodium-catalyzed cycloaddition between a variety of internal, unsymmetrical alkynes is described. We document the impact of both steric and electronic properties of the alkyne on reaction course, efficiency, and enantioselectivity. The substituent that better stabilizes a positive charge or the larger group, all else being equal, inserts distal to the carbonyl moiety in a predictable
描述了各种内部不对称炔烃之间的区域选择性、铑催化的环加成反应。我们记录了炔烃的空间和电子性质对反应过程、效率和对映选择性的影响。能更好地稳定正电荷或更大基团的取代基,在其他条件相同的情况下,以可预测和可控的方式插入羰基部分的远端。反应范围广,对映选择性高,为利用该反应作为合成工具时的底物选择提供了“指导手册”。