CONJUGATE ADDITION-REACTIONS OF ALLYLIC COPPER SPECIES DERIVED FROM GRIGNARD-REAGENTS - SYNTHETIC AND SPECTROSCOPIC ASPECTS

A general study on the 1,4-addition chemistry of allyl, methallyl, crotyl, and prenyl Grignard-derived organocopper reagents has been conducted. While diallylic cuprates formed from such species are not effective Michael donors, the 1:1:1 combination of an allylic Grignard, CuBr.SMe(2), and Me(3)SiCl leads to high yields of 1,4-adducts. The stereo- and regiochemistry associated with the allylic ligand, where appropriate, has also been examined. Low temperature C-13 NMR studies provide insight as to the nature of these complexes.