ALPHA-EFFECT WITH SUBSTITUTED N-METHYLBENZOHYDROXAMATES AND SUBSTITUTED PHENYLDIMETHYLSULFONIUM SALTS - TOWARD UNDERSTANDING OF AN INTRINSIC ALPHA-EFFECT
Kr. Fountain et al., ALPHA-EFFECT WITH SUBSTITUTED N-METHYLBENZOHYDROXAMATES AND SUBSTITUTED PHENYLDIMETHYLSULFONIUM SALTS - TOWARD UNDERSTANDING OF AN INTRINSIC ALPHA-EFFECT, Journal of organic chemistry, 62(9), 1997, pp. 2738-2741
Increasing electron demand in the reactions of G-NMBH anions with subs
tituted phenyldimethylsulfonium ions decreases the alpha-effect for th
e methyl transfers toward 1.0 (zero effect). An extrapolation shows th
e possibility of an inverse effect (<1.0). The reactivity of G-NMBH an
ions correlates with SET parameters and with the known propensity of p
henyldimethylsulfonium ions to accept a single electron into a sigma
C-S orbital concomitant with expulsion of a CH3 group. These correlati
ons indicate inclusion of some SET character into the wavefunction of
the S(N)2 transition state for these reactions, in agreement with the
Shaik and Pross SCD model of the S(N)2 reaction.