Manganese-catalysed Selective Upgrading of Primary Alcohols with Ethanol under Solvent-free Conditions

Abstract

Abstract The transition metal-catalysed Guerbet reaction allows the utilisation of feedstock alcohols and provides a direct and benign approach for the construction of C–C bonds. Herein, we describe the first non-noble metal manganese catalytic system that enables the efficient synthesis of higher-order alcohols via the cross-coupling of biomass-derived ethanol with primary alcohols. The process proceeded with high selectivity in the presence of a well-defined manganese pincer complex under solvent-free conditions. Catalyst loadings as low as 0.03 mol% can be used, leading to a record turnover number of 2336. A wide range of benzylic alcohols (> 20 examples) and aliphatic alcohols can be converted to longer linear alcohols in high yields and with excellent functional group tolerance.