α‐Alkylation of Mono‐Carbonyl Compounds with N‐Allylamines through Cooperative Actions of Lewis Acids and a Brønsted Base

• Published in: Asian journal of organic chemistry 2023-07, Vol.12 (7), p.n/a
• Main Authors: Dai, Changhang, Chapman, Matthew, Wasa, Masayuki
• Format: Article
• Language: English
• Subjects: Acid-base catalysis; Alkylation; Boron; Carbonyl compounds; Carbonyls; Cooperative catalysis; Frustrated Lewis pair; Imines; Lewis acid; Lewis acids; Organic chemistry; Stereoselectivity
• ISSN: 2193-5807; 2193-5815
• DOI: 10.1002/ajoc.202300198

We present a strategy for the union of N‐allylamines and carbonyl compounds by the concerted action of B(C6F5)3 and a N‐based Brønsted base under redox‐neutral conditions. The reaction of in situ generated conjugated iminium ions and enolates affords δ‐aminocarbonyl compounds without waste generation. Furthermore, we describe that the cooperative action of B(C6F5)3, a chiral Zn‐based complex, and an amine facilitates the stereoselective reaction of a glycinate Schiff base ester and an N‐allylamine to afford an α‐substituted α‐amino ester. We disclose a strategy for union of N‐allylamines and mono‐carbonyl compounds which can be performed under redox‐neutral and waste‐free conditions, and promoted through concerted action of B(C6F5)3 and a N‐based Brønsted base. A wide variety of α‐alkylated carbonyl compounds may be synthesized, through the reaction of an in situ generated iminium intermediate and boron‐enolate. Furthermore, we demonstrate that cooperative functions of B(C6F5)3, a chiral Zn‐based complex and an amine can be exploited for stereoselective α‐alkylation of glycinate Schiff bases.