Palladium- and Nickel-Catalyzed Reaction of Trimethylsilyl Cyanide with Acetylenes. Addition of Trimethylsilyl Cyanide to the Carbon-Carbon Triple Bonds

Article abstract of DOI:10.1021/jo00250a023

The reaction of trimethylsilyl cyanide (1) with acetylenes in the presence of a transition-metal complex was investigated.The structures of starting acetylenes and catalysts and both amounts of solvent and 1 highly affected product distributions.The PdCl2/pyridine catalyzed reaction of phenylacetylene and para-substituted phenylacetylenes with 1 resulted in the addition of 1 to the carbon-carbon triple bonds to give cyano-substituted vinylsilanes in good to high yields with high regio- and stereoselectivity.Ortho-substituted phenylacetylenes gave addition products less stereoselectively.Stereoselectivity affording Z adducts decreased in the order of para- <*> meta- <*> ortho-substituted phenylacetylenes.The NiCl2/DIBAH-catalyzed reaction of arylacetylenes was less stereoselective regardless of substitution patterns of arylacetylenes used.When the nickel-catalyzed reaction of arylacetylenes was run without solvent using an excess amount of 1, 5-amino-1H-pyrrole-2-carbonitriles were obtained as a single product, instead of the above simple addition products.The reaction of terminal aliphatic acetylenes with 1 also gave addition products with moderate stereoselectivity.Internal acetylenes gave complex mixtures including addition products and/or pyrrole derivatives.Diarylacetylenes afforded 5-amino-1H-pyrrole-2-carbonitriles selectively in the presence of a palladium or nickel catalyst (without solvent and an excess amount of 1).Intramolecular cyclization of a 1,6-diyne was also studied.