Reduction hydride ion

In one of these studies, Kurz and Frieden (1980) observed the first unexpectedly large secondary a-deuterium KIE. They found that the secondary a-deuterium KIE for the nonenzymatic hydride ion reduction of 4-cyano-2,6-dinitrobenzenesulfonate by NADH (reaction (44)) was 1.156 0.018 and 1.1454 0.0093 using direct and competitive kinetic methods, respectively. The corresponding equilibrium isotope effects (EIEs) were found to be 1.013 0.020 and 1.0347 0.0087, respectively. Thus, the secondary deuterium KIE was much larger than the EIE. The magnitude of a secondary a-deuterium KIE is normally attributed to the rehybridization of the a-carbon that takes place when the reactant is transformed into the... 

Nucleophilic substitutions at the azepine nucleus are confined mainly to derivatives of hydroazepines such as lactim ethers, imidoyl chlorides and amidines, and to hydride ion reductions of carbonyl and imine groups (see Section 5.16.3.5.2). In addition some transan-nular nucleophilic displacements have been described, but such reactions are not as common with azepines as with larger ring heterocycles. 

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