Iridium-catalyzed synthesis of β-methylated secondary alcohols using methanol

A general synthesis of beta-methylated secondary alcohols via tandem oc-methylation/transfer hydrogenation from non-methylated ketones with methanol by a Cp*Ir complex [Cp*Ir(2,2'-bpyO)(OH)]Na with a bipyridine-based functional ligand was reported. Remarkably, beta-methylated secondary alcohols can be obtained under milder reaction conditions using methanol as the methylating agent (C1 source) by employing this catalytic system. A wide range of structurally diverse ketones bearing different functional groups was methylated and hydrogenated with excellent toleration in fair to high yields. This method provides a readily available and highly efficient route to beta-methylated secondary alcohols using methanol. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This article reports a method for the synthesis of beta-methylated secondary alcohols from non-methylated ketones using a Cp*Ir complex and a functional ligand. The method provides a highly efficient route to beta-methylated secondary alcohols under mild reaction conditions.