Chiral Brønsted acid-catalyzed kinetic resolution of radical additions.

Abstract

Kinetic resolution has been a cornerstone for accessing enantioenriched molecules, but its application in radical chemistry has remained elusive due to the high reactivity of radical intermediates. Here, we present a new approach enabling precise Kinetic resolution in radical addition processes, yielding enantioenriched products and recovered starting materials with high efficiency. Two examples are provided: the Kinetic resolution of Minisci reactions between N-heterobiaryls or biaryls and glycine-derived redox-active esters under visible light irradiation with a chiral Brønsted acid catalyst, achieving high yields and enantioselectivities. The second example involves the reductive coupling of aldehydes with N-heterobiaryl-based olefins, enabling efficient synthesis of axially chiral heterobiaryls featuring both axial and remote central chirality. This work represents a conceptual breakthrough in asymmetric radical reactions, inspiring future developments in radical transformations using accessible racemic feedstocks.