Radical reactions of p-Nitrobenzylidene dichloride with lithium 2-nitropropan-2-ide. Consecutive S_RN1 and E_RC1 reactions

Abstract

The reaction of p-nitrobenzylidene dichloride with the lithium salt of 2-nitropropane gives initially the monosubstituted compound, p- NO₂C₆H₄CH(Cl)CMe₂NO₂, by a radical-anion radical chain, S_RN1 process. This compound then undergoes a radical-anion radical chain elimination reaction giving the styrene, p-NO₂C₆H₄CH=CMe₂, and the dimer of 2- nitropropane, Me₂C(NO₂)CMe₂NO₂. This latter reaction, which is designated ?E_RC1?, also occurs in competition with an E2 reaction in the reaction of the methanesulphonate, p-NO₂C₆H₄CH(OMs)CMe₂NO₂, with the 2- nitropropan-2-ide ion giving the above styrene and the enol methanesulphonate, p-NO₂C₆H₄C(OMs)=CMe₂, respectively. Catalytic, inhibition, and substituent effects are used to confirm the operation of these radical processes.