Synthesis of Sb-chiral organoantimony(III) compounds: Stepwise nucleophilic displacement reaction of tribromostibane via a bisethynylstibane intermediate

Treatment of bis(1-phenylethynyl)-p-tolylstibanes 2 with Grignard reagents resulted in nucleophilic displacement of one ethynyl group on 2 to afford t he monoethynyl compounds 3 on which the remaining ethynyl group could be re placed with other substituents by treatment with Grignard or organolithium reagents. These stepwise reactions provide an efficient method for the prep aration of a wide range of Sb-chiral organoantimony(III) compounds.