Asymmetric Mannich reaction of N-Boc aminosulfones with 3-methylbenzofuran-2 (3H)-Ones catalyzed by a chiral phase-transfer catalyst

An enantioselective Mannich reaction of N-Boc aminosulfones with 3-methylbenzofuran-2 (3H)-ones catalyzed by a quinine-derived bifunctional phase transfer catalyst was developed, by which a series of chiral benzofuranones bearing adjacent quaternary and tertiary carbon centers were obtained in high yields (up to 96%) with good diastereoselectivities (up to >99:1) and enantioselectivities (up to 98%).& COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

An enantioselective Mannich reaction between N-Boc aminosulfones and 3-methylbenzofuran-2(3H)-ones, catalyzed by a quinine-derived bifunctional phase transfer catalyst, was developed. This reaction afforded a series of chiral benzofuranones with adjacent quaternary and tertiary carbon centers in high yields (up to 96%) and exhibited good diastereoselectivities (up to >99:1) and enantioselectivities (up to 98%).