Linear versus bent transition‐state structures in hydride‐transfer processes mediated by NAD(P)H model systems; a theoretical investigation

Abstract

Abstract The reaction‐coordinate for degenerate hydride‐transfer between 1,4‐dihydro‐pyridine and the pyridinium‐ion was searched by MNDO calculations. A linear transition‐state (TS) structure is found to be strongly (> 16 kcal/mole) preferred over a bent TS. In the former, rotation about the C‐hydride‐C axis occurs unimpeded, thus creating a continuum of linear TS‐structures with ring to ring orientations varying between exo and endo.