Ethylzincation of monosubstituted alkenes catalyzed by EtMgBr-Cl2ZrCp2 andpalladium-catalyzed cross coupling of the resultant diisoalkylzinc derivatives

The reaction of monosubstituted alkenes with 0.5 molar equiv of Et2Zn in th e presence of a catalyst generated in situ by treatment of Cl2ZrCp2 with 2 molar equiv of EtMgBr produces regioselectively the corresponding diisoalky lzincs 1, generally in high yields. Their direct cross coupling with a vari ety of organic halides in the same reaction vessel can be achieved in good yields with a catalytic amount of a palladium complex.