Organozincs conjugate addition with

Simple organozinc reagents, such as diethylzinc, undergo conjugate addition with... 

Simple organozinc reagents, such as diethylzinc, undergo conjugate addition with 0.5 mol % CUO3SCF3 as catalyst in the presence of phoshines or phosphites. 

Organozinc reagents prepared from ultrasonic irradiation of organic halides with Li in the presence of ZnBr2 have recently been used for conjugate addition to a-enones [Eqs. (47) and (48)] (234,235). In the... 

There are a large number of reports on copper(I)-catalyzed conjugate additions, yet there is only scant information available about their reaction mechanisms. Recently, the conjugate addition of organozinc compounds to enones was found by Kitamura, Noyori, et al. to be catalyzed by N-benzylbenzenesulfonamide and CuCN, and the mechanism was scrutinized (Fig. 10.1). The kinetic rate was found to be first order in the concentrations of the catalyst that exist in equilibrium with R2Zn and enone [77]. 

Reformatsky first introduced electron-withdrawing substituents on the a-carbon of an organozinc halide, leading to the more reactive and thermally stable a-(alkoxycarbonyl)alkylzinc halides (123).107 Typically these reagents react with aldehydes or ketones to afford 3-hydroxy esters while nitriles afford 3-keto esters (Blaise reaction),l07b>c but 1,4-conjugate additions to select a,3 unsaturated ketones are precedented (Section 1.2.2.2.2). 

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