Copper(I) chloride-mediated oxidative coupling of alkenyltrialkylstannyl functions: efficient stereocontrolled syntheses of uniquely functionalized conjugated diene systems

Treatment of the β-trialkylstannyl α,β-unsaturated esters 1 - 9 with 2.5 equivalents of copper(I) chloride in N,N-dimethylformamide at room temperature results in the efficient, stereocontrolled production of the highly functionalized conjugated dienes 10 - 18 , respectively. In each of these oxidative couplings, production of 1 equivalent of product is accompanied by the formation of 2 equivalents of both the trialkylstannyl chloride and copper metal. Keywords: alkenyltrialkylstannanes, copper(I) chloride, transmetalation, conjugated dienes, oxidative coupling, β-trialkylstannyl α,β-unsaturated esters, substituted dialkyl muconates, organostannane, organocopper.