Conjugated microporous polymer as recyclable heterogeneous ligand for highly efficient regioselective hydrosilylation of allenes

Pyridines containing adjacent C≡C bonds was utilized as ligand units and integrated into the skeleton of conjugated microporous polymers. The resultant Pd-CMP-1 was first applied as a highly efficient heterogeneous catalytic system for the Pd-catalyzed allene hydrosilylation towards a wide range of allenes to produce branched allylsilanes with high regioselectivity. The ligand units of the polymer, along with the confinement effect of the porous structure, jointly regulated the regioselectivity. The parts-per-million (ppm) levels of Pd, coordinated with the recyclable heterogeneous ligand, shows promise for industrial application. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in the control of the regioselectivities in allene hydrosilylation.