CORRELATION BETWEEN THE REACTANT COMPLEX OR TRANSITION-STATE CONFORMATIONS ACID THE REACTIVITY OF 4-NITROPHENYL BENZOATE AND ITS SULFUR ANALOGS WITH ANIONIC NUCLEOPHILES BY COMPARATIVE MOLECULAR-FIELD ANALYSIS(COMFA)

A comparative molecular field analysis (CoMFA) was carried out for the correlation of the transition stale structures and the reaction rates for the S(N)2 reaction of 4-nitrophenyl benzoate and its sulfur analo gs with anionic nucleophiles. The CoMFA analysis showed that both ster ic and electrostatic effects are important, and the steric contributio n increased when nucleophiles are alkoxides or arylsulfides. In this s tudy, we have demonstrated that the CoMFA analysis can be expanded bey ond the scope of dealing with reactants and products. The reactant com plex and transition state conformations generated along the reaction p ath can be more appropriately used for the correlation of structures a nd reaction rates.