Calcium Organic Complex Catalyzed Dehydrogenation Coupling Reaction Of Silane And Terminal Alkyne

Alkynylsilanes are an important class of organic compound,and dehydrogenative coupling of hydrosilanes with terminal alkynes provides a convenient and simple route to alkynylsilanes.On the other hand,calcium is an abundant,biocompatible and environmentally friendly element,and using of organocalcium complexes as catalytic reagents in organic synthesis recently attracted increasing attentions.In this paper,organocalcium complexes were investigated to catalyze the dehydrocoupling reactions of hydrosilanes with terminal alkynes and to catalyze the dehydrocoupling-hydrosilylation tandem reactions of hydrosilanes with terminal alkynes.With a calcium alkyl complex[LCaCH₂SiMe₃](L=[MeC(NDipp)CHC(^tBu)NCH₂CH₂N(Me)CH₂CH₂NMe₂]^-,Dipp=2,6-(ⁱPr)₂C₆H₃)as the catalyst,complex 1 can catalyze the 1 equive n-Hex SiH₃ with 3.5 equvie terminal alkynes reaction to synthesize trialkynylsilanes using 5?10 mol%catalyst at 80 ? to give a series of trialkynylsilanes in 57?99%yields within 12?24 h.Complex 1catalyzed the reaction of 1 equive Et₂SiH₂ with 1.2 equvie terminal alkynes to synthesize monoalkynylsilanes using 5 mol%catalyst at 60 ? to give a series of monoalkynylsilanes in 76?92%yields within 3?36 h.Subsequently,we studied complex 1 can also catalyze the direct synthesis of tris(silanes)by the one-pot method of n-HexSiH₃ with terminal alkynes.Using 10-20 mol%of complex 1 as a catalyst,4equivalents of n-hexylsilane were reacted with 1 equivalent of terminal alkynes for 12-24 h at a suitable reaction temperature to give a series of tris(silanes)in 66?94%yields.