| A mild method of achieving transition metal catalyzed conjugate addition chemistry is described. Optically active 2-alkenyl-5-substituted-1,3-dioxolanes were shown to undergo palladium- and nickel-catalyzed conjugate addition reactions with organotin and organoboron reagents. Successful coupling of these substrates with vinyl-, 1-(ethoxyvinyl)-, and phenyltrialkytin reagents occurs under conditions of palladium catalysis to produce lithium 2-substituted-2- ((E)-alkenyloxy) ethanoates in 40-82% yield. Nickel catalysis has also been found to effect the coupling of Na(MeO);Also presented, is a new, direct method for the conversion of enals and enones into 1-(trialkylsilyloxy)-allylnickel(II) chloride complexes. The combination of Ni(COD);The bis((m-chloro)(1,2,3-n... |
