Cross-coupling copper® chloride

A catalytic version of the coupling was also developed, by using 10 mol % of CuCl2 and 20 mol % of sparteine 1 (silver chloride was used as a stoichiometric oxidant to regenerate the copper (II) oxidant). This catalytic system was applied to the asymmetric cross-coupling leading to 101 in a 41% yield and 32% ee. 

Scheme 2.S0. Copper(l) chloride as a promoter of Stille cross-coupling.

GooBen LJ, Zimmermann B, Knauber T (2008) Palladium/copper-catalyzed decarboxylative cross-coupling of aryl chlorides with potassium carboxylates. Angew Chem Int Ed 47 7103-7106... 

Kang, S. K., Kim, J. S., Choi, S. C. Copper- and manganese-catalyzed cross-coupling of organostannanes with organic iodides in the presence of sodium chloride. J. Org. Chem. 1997, 62, 4208-4209. 

Cross-couplings. The conditions for coupling of l,3-butadien-2-ylmagnesium chloride with CD-bromoalkanonitriles have been optimized. A new soluble copper catalyst for coupling reactions is CuBr-PhSLi-LiBr-THF. ... 

Cross-coupling reactions. The Wurtz coupling of an alkyl iodide and an alkyl bromide or two bromides by Sml is catalyzed by a copper salt. Organic chlorides RCl undergo photoinduced dechlorination to afford RH, but under CO the products are ketones RCOR. a,a-Difluorobenzyltrimethylsilane is a useful precursor of the substituted benzyl anion, accessible from cross-coupling of the benzyl chloride and Me SiCl. ... 

We have found that alkynylsilanes are smoothly converted into alkynylcopper compounds by treatment with CuCl in l,3-dimethyl-2-imidazohdinone (DMI) the copper reagents can be isolated in good yields [563]. This study was the first example of preparation and isolation of organocopper compounds by use of organosilicon reagents. The Si-Cu transmetalation is applicable to the synthesis of alkynyl ketones by Cu-catalyzed alkynylation of acid chlorides (Scheme 10.217). We have also shown that a Cu-mediated system is effective in the cross-coupling reaction between arylsilanes or heteroarylsilanes and aryl hahdes [564]. 

---