Diarylmethanes through an Unprecedented Palladium-Catalyzed C-C Cross-Coupling of 1-(Aryl)methoxy-1 H-Benzotriazoles with Arylboronic Acids

1-(Aryl)methoxy-1H-benzotriazoles (ArCH₂OBt) are bench-stable reagents that are prepared readily from 1H-benzotriazol-1-yl-4-methylbenzenesulfonate and benzylic alcohols. These compounds, which contain a N-O-C bond, undergo cross-coupling with arylboronic acids by C-O bond scission with catalysts that comprise Pd(OAc)₂ and biarylphosphine ligands. Such reactivity of ArCH₂OBt derivatives, which lead to diarylmethanes, has not been described previously and constitutes a new activation of benzylic alcohols. With regard to the various ligand-metal complexes that support catalytic activity, it appears that those with smaller "percent buried volumes" (%V_bur) provide better outcomes. This factor has been evaluated in the initial optimization studies and in further reactions with difficult coupling partners. Ligand electronics of the biaryl moiety seem to play a lesser role in this type of reaction. The biscoordinating bis[(2-diphenylphosphino)phenyl] ether appears to be suitable to improve the yields of low-yielding reactions. Phosphine fine: 1-(Aryl)methoxy-1H-benzotriazoles (ArCH₂OBt), which contain a N-O-C bond, undergo cross-coupling with arylboronic acids by C-O bond scission with catalysts that comprise Pd(OAc)₂ and biarylphosphine ligands. Such reactivity of ArCH₂OBt derivatives, which lead to diarylmethanes, has not been described previously and constitutes a new activation of benzylic alcohols.