REACTION OF ARYLIMODIMAGNESIUM WITH AROMATIC BIFUNCTIONAL NITRILES - COMPETITION AND OR COOPERATION OF FUNCTIONAL-GROUPS AFFECTED BY ELECTRON-ACCEPTING ABILITY AND LOCATION/
M. Okubo et al., REACTION OF ARYLIMODIMAGNESIUM WITH AROMATIC BIFUNCTIONAL NITRILES - COMPETITION AND OR COOPERATION OF FUNCTIONAL-GROUPS AFFECTED BY ELECTRON-ACCEPTING ABILITY AND LOCATION/, Journal of physical organic chemistry, 10(4), 1997, pp. 242-252
The reactions of aryliminodimagnesium [ArN(MgBr)(2)IDMg] with p'-subst
ituted p-cyanobenzophenornes, 1-cyano-9-fluorenone, o-, m- and p-dicya
nobenzenes and o-, m- and p-nitrobenzonitriles were examined, and the
relative yields of products were referred to the previous results of e
lectron spin resonance studies. The products of condensation with carb
onyl and nitro groups and of addition to cyano groups were formed. Fro
m the variations of the yields caused by the molar ratio of the magnes
ium reagent versus substrates and by the substituents of both reactant
s, the preferred groups were determined, The groups of p- and m-substr
ates are consistent with the position of highest density of free elect
rons in the anion radicals, whereas those of the o-substrates are inco
nsistent. The consistency indicate competition of functional groups re
flecting the relative ability of single electron acceptance from the r
eagent, whereas the inconsistency is ascribed to cooperation of neighb
ouring groups for sigma-complexation with the Mg atom of the reagent,
The categories of competition and cooperation are discussed in relatio
n to fundamental features and general governing factors proposed for t
he IDMg reactions of monofunctional substrates. (C) 1997 by John Wiley
& Sons, Ltd.