title: Kinetics and mechanism of the addition of benzylamines to benzylidenemalononitriles in acetonitrile
abstract: Nucleophilic addition reactions of benzylamines (BA) to benzylidenemalononitrile (BMN) have been studied in acetonitrile at 15.0 degrees C. The rate is first-order with respect to both BA and BMN and no base catalysis is observed. The rate decreases as the electron-withdrawing power of the substituent (Y) in the substrate increases (rho Y < 0). This is in contrast to the similar reactions of beta-nitrostyrenes (NS) with BAs in acetonitrile and the addition reactions of NS and BMN in aqueous solution (rho Y > 0). This sign change of rho Y is considered to result from the strong electron-withdrawing power of the (CN)2 group in BMN, which leads to polarization of C alpha delta+C delta- (CN)2 in the transition state. The mechanism of amine addition to BMN in acetonitrile is radically different from that in water. The reaction is predicted to proceed concertedly in a single step with a hydrogen-bonded, four-center cyclic transition state.
authors.affiliation: Department of Chemistry, Chonbuk National University, Korea.
authors.initials: HK
authors.lastname: Oh
authors.initials: JH
authors.lastname: Yang
authors.initials: HW
authors.lastname: Lee
authors.initials: I
authors.lastname: Lee