The regio- and stereoselectivity of the palladium-catalysed cross-coupling reactions of indium organometallics with stereodefined 1-haloalkenes and 1,1-dihaloalkenes have been studied. Triorganoindium reagents (R3In; R = alkyl, alkenyl, aryl and alkynyl) can be stereospecifically coupled with stereodefined alkenyl iodides in good yields and short reaction times under palladium catalysis. Additionally, the palladium- catalysed cross-coupling reaction of R3In (90 mol%) with 1,1-dibromo-1-alkenes gave dicoupling products in high yields. When the reaction was performed with 40 mol% of aryl-, vinyl- and alkynylindium derivatives, trans-selective monosubstitution products were obtained in moderate to good yields. These selective couplings were performed with [Pd2dba3]/P(2-furyl)3 (1:1, 2 mol%) at 0 °C or, for 1,1-dibromo-1-alkenes with an aromatic group in the b-position, Pd(DPEPhos)Cl2] (2 mol%) at room temperature as the catalytic system. The resulting (Z)-monobromoalkenes can be further functionalized by cross-coupling reaction with various R3In (R = alkyl, aryl and alkynyl) in the presence of [Pd(tBu3P)2] as catalyst, at room temperature, to provide trisubstituted olefins in good yields.
