Direct Catalytic Asymmetric Aldol Reaction of α‑Vinyl Acetamide

A direct
catalytic asymmetric aldol addition of an α-vinyl
7-azaindoline amide to both aromatic and aliphatic aldehydes was promoted
by a cooperative acid/base catalyst in a stereodivergent manner. The
key structural element, a 7-azaindoline moiety, facilitated catalytic
enolization, allowing for subsequent stereoselective aldol addition.
Enantioselective synthesis of the key intermediate of blumiolide C
and kainic acid supported the synthetic utility of this protocol.