125643-03-0Relevant academic research and scientific papers
Carboalumination of 1-Alkynes and in Situ Transmetalation to Higher Order Cyanocuprates. Stereospecific Synthesis of Tri- and Disubstituted Olefins by Conjugate Addition to Enones
Ireland, Robert E.,Wipf, Peter
, p. 1425 - 1426 (1990)
A method is described for the direct carboalumination and in situ cuprate exchange that makes possible the conjugate addition of disubstituted (R, CH3) or monosubstituted (R, H) vinyl anions to α,β-unsaturated ketones.The process results in high yields (63-95percent) of conjugate addition products without the customary intervention of the more standard vinyl iodide and then cuprate formation.
Transmetalation Reactions of Alkenylalanes: Copper-Catalyzed Conjugate Adition to Enones
Wipf, Peter,Smitrovich, Jacqueline H.,Moon, Choong-Woon
, p. 3178 - 3186 (2007/10/02)
An improved synthetic strategy for the in situ preparation of vinyl cuprates from alkynes is presented and used for the stereospecific synthesis of di-, tri-, and tetrasubstituted olefins.Hydroalumination or Cp2ZrCl2-catalyzed carboalumination of alkynes, followed by in situ transmetalation to bis-alkynyl-copper complex C)2CuCN>Li2 and addition of enones, led to the isolation of 1,4-addition products in high yields.Stoichiometric or catalytic amounts of copper complex gave similar results.However, in the presence of less than 10 mol percent of Cu(I) complex, side products were formed and a significant drop in the yield of the desired conjugate addition product was observed.An ate-transfer mechanism is postulated for the rapid exchange of vinyl ligands from Al(III) to Cu(I) at low temperatures.
