Alkylation organozincate conjugate

Keywords Organozinc, Organolithium, Grignard reagent, Copper, Conjugate addition, Nucleophilic addition, Alkylation, Activated olefin, Enone, Nitroalkene, p-Substituted carbonyl... 

Organozincs generated under similar conditions have been shown to add to optically active vinyl phosphine oxides with retention of configuration at phosphorus [63] (Scheme 8). In this case a 1 1 zinc/copper couple was employed to activate the zinc. The one-pot reaction proceeded best with tertiary or secondary alkyl halides. The resulting phosphine oxides are used as chiral ligands for catalysts in asymmetric synthesis and were previously only available by reaction with the analogous cuprate [147] since conjugate addition of simple alkyl halides normally results in polymerisation. 

The addition of Lithium Bromide and Lil was shown to enhance the rate of organozinc formation from primary alkyl chlorides, sulfonates, and phosphonates, and zinc dust. Beneficial effects of Lil addition have also been reported for Heck-type coupling reactions and in conjugate addition to chiral vinyl sulfoximines. ... 

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