Organocopper/zinc reagents

Chemla, Normant and coworkers also reported a one-pot 1,4-addition/carbocyclization domino sequence as a new access to 3-carbomethoxypyrrolidines. Conjugate addition of the mixed organocopper-zinc reagent n-BuCu(CN)ZnBr LiBr to the Michael acceptor 427 in ether at room temperature directly led after hydrolysis to the 3-carbomethoxypyr-rolidine 428 as a 84/16 diastereomeric mixture, the trans disubstituted isomer being predominant (equation 185). A similar explanation as described above was proposed for the stereochemical outcome264. 

A second type of such an organocopper-zinc reagent was prepared, and reacted as shown in the accompanying scheme [300],... 

Organocopper/zinc reagents substituted by a phenylthio group at the "/-position can be prepared, and also show enhanced reactivity with electrophiles (equation II). 

Reaction with -alkylthio nitro olefins. Nitro alkenes bearing an alkylthio or phenylsulfonyl group at the -position undergo addition-elimination reactions with organocopper/zinc reagents to provide functionalized (E)-nitro alkenes. 

Organocopper/zinc reagents. 18,262-Preparation. Alkylzinc-copper r activated Zn and then with Cu(OAck-lj Allylic displacements. 7t-Complei reaction with the organocopper/zinc rcaj of configuration. For chain extension is reacted with MeCu(CN)Li and then... 

Reaction of alkynylcoppers with 5 cquiv. of iodomethylzinc iodide results in insertion of four methylene groups to provide organocopper/zinc reagents of type 2, which can be trapped by allylic halides (equation I). 

Disubstituted cyclobutene-1,2-diones." These products can be prepared by reaction of 3,4-dichlorocyclobutene-l,2-dioncs with functionalized organocopper/zinc reagents. 

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