The effect of the ring size of the dithiolato leaving group on the orientation of β-elimination in the nickel-catalysed alkenation of cyclic dithioacetals with Me2SiCH2MgCl

Abstract

The product distribution (allyl-vs, vinyl-silanes) of the reactions of dithioacetals derived from alkyl aryl ketones with Me₃SiCH₂MgCl surprisingly depends on ring size of the cyclic dithioacetals, the five-membered ring substrates affording allylsilane as the major product while the six-membered analogues yield vinylsilanes predominantly. These results indicate that the leaving group, dithiolato moiety, may remain coordinated to the metal centre during the course of the catalytic process.