Synthesis of Aminosilane Chemical Vapor Deposition Precursors andPolycarbosilazanes through Manganese-Catalyzed Si-NDehydrocoupling br

CompoundsthatfeatureSi-Nbondsareofwidespread importance to the electronics and coating industries.Aminosilanes and polysilazanes are currently prepared by addingamines to halosilanes, an inefficient methodology that generatesstoichiometric quantities of ammonium salt waste. Herein, wedescribe the syntheses of aminosilane chemical vapor depositionprecursors, polycarbosilazanes, and perhydropolysilazane throughthe ambient-temperature dehydrocoupling of amines to silane(SiH4). Specifically, the beta-diketiminate manganese hydride dimer[(2,6-iPr2PhBDI)Mn(mu-H)]2has been used to catalyze the formationof commercial aminosilane monomers from secondary and primaryamines, highly cross-linked polycarbosilazane powders fromdiamines and triamines, and perhydropolysilazane from ammonia.The mechanism of dehydrocoupling was explored, and the addition of isopropylamine to [(2,6-iPr2PhBDI)Mn(mu-H)]2resulted in Sigma-bond metathesis to eliminate H2and generate [(2,6-iPr2PhBDI)Mn(mu-NHiPr)]2. In the presence of SiH4,H-Si addition across newlyformed Mn-N bonds regenerates the precatalyst, offering a straightforward catalytic cycle for halogen-free Si-N bond formation.