Homolytic Rearrangements of Ketenimines to Nitriles: Employments of Hammett Dual Parameters
作者:Sung Soo Kim、Bo Liu、Chul Hyun Park、Kwang Ho Lee
DOI:10.1021/jo971844c
日期:1998.3.1
The thermal isomerizations of ketenimines co nitriles involve a "homolytic" transition state (TS) as the major contributor to the structure of the TS. The rates have been fitted to Hammett dual correlations. The magnitudes of \rho(.)/rho\ represent the relative weights in the TS assuming homolytic character.
Hydride Reduction by a Sodium Hydride-Iodide Composite
作者:Pei Chui Too、Guo Hao Chan、Ya Lin Tnay、Hajime Hirao、Shunsuke Chiba
DOI:10.1002/anie.201600305
日期:2016.3.7
Sodium hydride (NaH) is widely used as a Brønsted base in chemical synthesis and reacts with various Brønsted acids, whereas it rarely behaves as a reducing reagent through delivery of the hydride to polar π electrophiles. This study presents a series of reduction reactions of nitriles, amides, and imines as enabled by NaH in the presence of LiI or NaI. This remarkably simple protocol endows NaH with
Thermal Isomerizations of Ketenimines to Nitriles: Evaluations of Sigma-Dot (σ<sup>•</sup>) Constants for Spin-Delocalizations
作者:Sung Soo Kim、Yu Zhu、Kwang Ho Lee
DOI:10.1021/jo991186r
日期:2000.5.1
N-(substituted benzyl) ketenimines were measured at 40, 50, 60, and 70 degrees C. Activation parameters DeltaH()(Y) and DeltaS()(Y) were obtained using the Eyring equation. The relative rates (k(Y)/k(H)) were fitted into Hammett single correlations (log k(Y)/k(H) = rhosigma and log k(Y)/k(H) = rho(*)sigma(*)). The single correlations have been compared with Hammett dual correlations (log k(Y)/k(H) = rhosigma