Synthesized, isolated, and characterized by X-ray crystallography and NMR spectroscopic studies, lithium phosphidoaluminate iBu3 AlPPh2 Li(THF)3 has been tested as a catalyst for hydrophosphination of alkynes, alkenes, and carbodiimides. Based on the collective evidence of stoichiometric reactions, NMR monitoring studies, kinetic analysis, and DFT calculations, a mechanism involving deprotonation, alkyne insertion, and protonolysis is proposed for the [iBu3 AlHLi]2 aluminate catalyzed hydrophosphination of alkynes with diphenylphosphine. This study enhances further the development of transition-metal-free, atom-economical homogeneous catalysis using common sustainable main-group metals.
Keywords: aluminate; homogeneous catalysis; hydrophosphination; lithium; phosphines.
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.