Highly efficient NHC-iridium-catalyzed ?-methylation of alcohols with methanol at low catalyst loadings

The methylation of alcohols is great importance since a broad number bioactive and pharmaceutical contain methyl groups. Here, highly efficient ?-methylation primary secondary with methanol has been achieved by using bis-N-heterocyclic carbene iridium (bis-NHC-Ir) complexes. Broad substrate scope up to quantitative yields were at low catalyst loadings only hydrogen water as by-products. protocol was readily extended the ?-alkylation several alcohols. Control experiments, along DFT calculations crystallographic studies, revealed that ligand effect critical their excellent catalytic performance, shedding light on more challenging Guerbet reactions simple