Copper-catalysed asymmetric cross-coupling reactions tolerant of highly reactive radicals.

Abstract

Achieving high enantioselectivity in asymmetric catalysis, especially with very reactive species such as radicals, often comes at the expense of generality. Radicals with exceptionally high reactivity are typically unsuitable for existing asymmetric methodologies. Here we present a general catalytic approach to asymmetric radical cross-coupling that combines copper-catalysed enantioselective stereocentre resolution or formation with copper-mediated, chirality-transferring radical substitution. This sequential strategy enables the efficient coupling of over 50 distinct carbon-, nitrogen-, oxygen-, sulfur- and phosphorus-centred radicals, including highly reactive methyl, tert-butoxyl and phenyl radicals, yielding structurally diverse C-, P- and S-chiral compounds with outstanding enantioselectivity. Our method thus provides a unified platform for the synthesis of carbon, phosphorus and sulfur stereocentres, with important implications for the preparation of chiral molecules relevant to medicinal chemistry and related disciplines. Furthermore, this sequential stereodiscrimination and chirality transfer strategy offers a promising blueprint for the development of highly enantioselective methodologies applicable to other classes of highly reactive species beyond radicals.