Aryliminodimagnesium Reagents. VI. The Reactions with Conjugated Carbonyl Compounds. The Initial Coordination and the Electron-transfer in the Reactions of Organomagnesium Reagents

Abstract

Abstract The reactions of aryliminodimagnesium reagents (ArN(MgBr)2) with benzylideneacetophenones, quinones, and benzils were examined. Among the product-distributions in the reactions with the enones and the α-diketones, some examples in which p-MeO-substituted substrates gave higher yields of condensation products were obtained. The results are in contrast with the product-distributions in the reaction of ArMgBr with Ar1COAr2 and that of ArN(MgBr)2 with Ar1NO2: p-Cl-Substituted substrates are advantageous for the formation of addition and/or condensation products. These reactions of the two organomagnesium reagents were classified into “coordination controlled” and “electron-transfer controlled” ones on the basis of the combination of electron-donating ability of reagents with the electron-accepting ability of substrates. The classification was illustrated also on the basis of the relative difference of the energy levels of HOMO’s and LUMO’s of the reactants.