Cationic aluminum complexes supported on tridentate O,N,O platform and activity studies in the ring opening polymerization of ε-caprolactone

A tridentate ligand (LONO-H2) containing O,N,O donors was cleanly metallated by one equivalent of Me2AlCl, followed by chloride abstraction by GaCl3, AlCl3, or Na[BArF24], resulting in cationic Al complexes with the corresponding counter ion [LONOAl(THF)3]+[A]- (A = [GaCl4]- (1), [AlCl4]- (2), [BArF24]- (3)). Complexes 1 and 3 are efficient catalysts for the polymerization of neat ?-caprolactone at room temperature.

Automated summary

A tridentate ligand with O,N,O donors was metallated by Me2AlCl and then reacted with GaCl3, AlCl3, or Na[BArF24] to form cationic Al complexes. These complexes, particularly 1 and 3, showed efficient catalytic activity in the polymerization of neat ?-caprolactone at room temperature.