Synthesis and reactions of aluminum sulfonamide alkyls and hydride

摘要

Aluminum compounds supported by a sulfonamide ligand are described. Reaction of AlEt3 with 1 equiv of the sulfonyl amine ArNH(SO2-p-Tol) (Ar = 2,6-iPr(2)C(6)H(3), Tol = 4-MeC6H4) yielded the dimeric aluminum species [ArN(SO2-p-Tol)AlEt2](2) (1), and reactions of AlEt3 and AlH3 center dot NMe3 with 2 equiv of ArNH(SO2-p-Tol) yielded the aluminum bis(sulfonamide) species [ArN(SO2-p-Tol)](2)AlEt (2) and [ArN(SO2-p-Tol)](2)AlH (3). The iodide species [ArN(SO2-p-Tol)AlI2](2) (4) and [ArN(SO2-p-Tol)](2)AlI (5) were prepared by the reaction of 1 and 2 with iodine. Reaction of 3 with PhNH2, HCCPh, and Ph2CO yielded [ArN(SO2-p-Tol)](2)AlNHPh (6), [ArN(SO2-p-Tol)](2)AlCCPh (7), and [ArN(SO2-p-Tol)](2)AlOCHPh2 (8). Treatment of 6 with (BuLi)-Li-n in n-hexane led to a ligand transfer reaction to give the dimeric lithium salt [ArN(SO2-p-Tol)Li(THF)(2)](2) (9). Compounds 1-4 and 7-9 have been characterized by X-ray single-crystal analysis, which disclosed that the aluminum mono(sulfonamide) compounds adopt a dimeric NSOAlNSOAl eight-membered-ring structure while the aluminum bis(sulfonamide) species are monomeric species with a five-coordinate aluminum center. Interestingly, the lithium salt 9 has a dimeric structure with an OSOLiOSOLi eight-membered-ring core. Compounds 3 and 8 are found to be active for lactide polymerization at high temperature.