Catalyst-controlled and visible light-induced acylmethylation and bromoacylmethylation of Morita–Baylis–Hillman acetates with α-bromo ketones: access to highly functionalized 1,5-dicarbonyl compounds

Abstract

Photoinduced acylmethyl radical procedures for the efficient and simple preparation of highly functionalized 1,5-dicarbonyl compounds from Morita–Baylis–Hillman acetates with α-bromo ketones are developed. The acylmethylation is carried out with rose bengal as an organophotocatalyst at room temperature under metal- and oxidant-free conditions. In particular, the simple photoinduced bromoacylmethylation is performed via a fac-Ir(ppy)₃-catalyzed atom-transfer radical addition (ATRA) strategy under visible light irradiation. These methods are attractive and valuable due to their mild reaction conditions, a broad substrate scope and good functional group tolerance.