Tuning the selectivity in iridium-catalyzed acceptorless dehydrogenative coupling of primary alcohols

An acceptorless dehydrogenative coupling of primary alcohols to carboxylic acids/carboxylates, esters, and Guerbet alcohols ( via both homo- and cross-β-alkylation of the alcohols) in the presence of an N-heterocyclic carbene iridium( i ) catalyst was developed under aerobic conditions. The product selectivity can be easily tuned among the products with a single catalyst through simple modification of the reaction conditions, such as the catalyst and base amounts, the choice of base, and the reaction temperature. A single NHC-Ir catalyst allowed for the selective synthesis of carboxylic acids/carboxylates, esters, and Guerbet alcohols via the ADC of primary alcohols.