Stereoselective hydrozirconation of alkynylsulfide and regioselective synthesis of haloalkenyl sulfide via electrophile-switched halogenation of thioalkenyl zirconocene

A New Strategy for the Synthesis of Organosilicon Compounds of Cyclopropane Derivatives

The one-pot reaction of tetra-substituted cyclopropyl benzyl bromide with tris(trimethylsilyl)methyllithium (TsiLi) and carbon disulfide resulted in 3-(4-((((trimethylsilyl)ethynyl)thio)methyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (3) and 3-(4-((trimethylsilyl)methyl)phenyl)cyclopropane-1,2-dicarbonitrile (4) in excellent yield. The reaction in the absence of carbon disulfide yielded 3-(4-(2,2,2-tris(trimethylsilyl)ethyl)phenyl)cyclopropane-1,1,2,2-tetracarbonitrile (5) in excellent yield at 0°C to room temperature. All structures were characterised by IR, 1H NMR, and 13C NMR spectroscopies. The reaction mechanisms are discussed.