3-Alkenyl-2-silyloxyindoles: An Enabling, Yet Understated Progeny of Vinylogous Carbon Nucleophiles

We introduce novel 3-alkenyl-2-silyloxyindole nucleophiles and demonstrate their utility by developing an unprecedented vinylogous Mukaiyama-type aldol reaction with aromatic aldehydes. This reaction displays excellent levels of ?- site selectivity and diastereoselectivity and delivers valuable hydroxylated oxindoles bearing a substituted exocyclic double bond at the C-3 position. A preliminary trial of an asymmetric, catalytic version was conducted, and it showed promising enantioselectivity for the desired vinylogous aldol products.