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.

本研究实现了α-乙烯基7-氮杂吲哚啉（7-azaindoline）酰胺与芳香醛及脂肪醛间的直接催化不对称羟醛加成反应，该反应由协同酸碱催化剂催化，以立体发散模式进行。该反应的关键结构单元为7-氮杂吲哚啉基团，其可有效促进催化烯醇化过程，从而实现后续的立体选择性羟醛加成反应。通过对布鲁米内酯C（blumiolide C）与红藻氨酸（kainic acid）关键中间体的对映选择性合成，证实了该合成策略的合成应用价值。