Stereoselective C-X and regioselective C-H activation to,and selective C(sp2)-C(sp3) reductive elimination from,platinum compounds with thiophene-derived ligands

Several thiophene-based N^C ligands were synthesized. Strategically, a bromide was incorporated on the 2-position of the thiophene ring. When allowed to react with the platinum tetramethyl dimer, [Pt₂Me₄(µ-SMe₂)₂], platinum(IV) platinacycles were formed by oxidative addition of the C(sp²)-X bond. These platinum(IV) compounds were characterized by NMR and HRMS. The platinum (IV) compounds were subsequently subjected to thermolysis. A series of reactions occurred, including selective C-C reduction elimination and selective C-H oxidative addition, giving mixtures of platinum(II) products with varying degrees of regioselectivity.