Theoretical Studies on the Nucleophilic Substitution Reactions of Y-Benzoylchlorides

초록

Gas phase nucleophilic substitution reactions of Y-Benzoylchloride with X-phenoxides and X-thiophenoxides nucleophiles were investigated theoretically using the ONIOM method of B3LYP/6-31++G**:B3LYP/3-21G* level. For a weaker nucleophile of thiophenoxide, a early TS is obtained with an increased bond making and breaking but a stronger nucleophile of phenoxide, later TS is obtained with a less increased bond making and breaking. According to the Leffler-Grunwald rate-equlibrium relationship, more endothermic reactions of phenoxides lead to a later TS (65%) than the less percentage changes bond order.