Unveiling the role of external electric fields and substituent effects on the reactivity and mechanism of hydration reaction of nitriles to amides

The hydration of nitriles to amides studied under catalyst-free conditions by exerting an electron withdrawing (EW)/ electron releasing (ER) substituent effects, external electric field is proposed in the present work. The global electrophilicity ω index, when analyzed at the ground state of a set of para/meta-substituted benzonitriles, exhibits a consistent linear correlation with the σp/σm Hammett substituent constants. The theoretical scale effectively captures the electrophilic activation or deactivation effects induced by EW and ER substituents in benzonitriles. Furthermore, the external electric field (EEF) has a notable impact on the intrinsic electrophilicity of nitriles, as measured by the global electrophilicity ω index. The degree of change in electrophilicity is contingent upon both the directionality and intensity of the applied electric field