Diphenyl copper bromide/chloride

The Michael addition of organometallic nucleophiles to enones in the presence of copper(I) salts produces enolates which on treatment with phenylselenenyl bromide give a-seleno ketones. For example, the reaction of the zirconium enolate of 15 with a mixture of phenylselenenyl bromide and diphenyl diselenide affords a mixture of diastereomeric (2R)- and (2V)-phenylse-leno)cyclopentanones 16 in 50% and 31 % isolated yield, respectively12. The analogous reaction with phenylselenenyl chloride gives only the tram-isomer in 27% yield formation of the cw-product is not observed12. 

Pd2(DBA)3/BINAP system (DBA = dibenzylideneacetone BINAP = 2,2-bis(diphenyl-phosphanyl)-l,1-binaphthyl). Best results were obtained using electron-deficient aryl bromides. Aryl chlorides of any type, however, failed to react under these conditions. The aryl-aziridine coupling reaction could also be carried out with arylboronic acids using a copper catalyst (Scheme 55) <2003JOC2045>. 

ALKENES Allyl dimethyldithiocarbamate. Bis(t -cyclopentadienyl)niobium trihydride. Cyanogen bromide. Di-n-butylcopperlithium. a,o-Dichloromethyl methyl ether. 2,3-Dimethyl-2-butylborane. N,N-Dimethyl dichlorophosphoramide. Diphenyl diselenide. Di-n-propylcopperlithium. Ferric chloride. Grignard reagents. Iodine. Lithium phenylethynolate. Lithium 2,2,6,6-tetramethylpiperidide. Methyl iodide. o-Nitro-phenyl selenocyanate. Propargyl bromide. rra s-l-Propenyllithium. Selenium. Tetrakis(triphenylphosphine)palladium. Titanium(IH) chloride. Titanium trichloride-Lithium aluminum hydride. p-Toluenesulfonylhydrazine. Triphenylphosphine. Vinyl-copper reagents. Vinyllithium. Zinc. 

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