Tandem Cross Coupling Reaction of Alcohols for Sustainable Synthesis of β-Alkylated Secondary Alcohols and Flavan Derivatives

A Ru(II) NHC complex (loading down to 0.001 mol%) catalyzed cross coupling of a broad range of aromatic, aliphatic and heterocyclic alcohols is reported. This protocol also functioned efficiently under solvent-free conditions. Remarkably, this catalytic system disclosed so far the highest TON of 288000 for the cross coupling of alcohols. Notably, this methodology was successfully applied for the one-pot synthesis of a range of flavan derivatives. A detailed DFT studies and kinetic experiments were performed to understand the reaction mechanism as well as the high reactivity of this catalytic system.