The High Selectivity of the Cp<sub>2</sub>ZrHCl Reducing Agent for Imides: A Combined Experimental and Theoretical Study on γ-Lactam and Isoxazolidinone Derivatives
作者:Giuseppe Lanza、Maria A. Chiacchio、Salvatore V. Giofrè、Roberto Romeo、Pedro Merino
DOI:10.1002/ejoc.201201186
日期:2013.1
Selective reductions of semicyclic imides either to hemiaminals (endo carbonyl reduction) or to aldehydes and amines (exo carbonyl reduction) in high yields by Schwartz’s reagent (Cp2ZrHCl) are reported. Mechanistic aspects of these reactions have been investigated at the DFT ab initio level with consideration of implicit solvent effects and thermal and pressure corrections to 298 K/1 atm. The reactions
据报道,半环酰亚胺通过施瓦茨试剂 (Cp2ZrHCl) 以高产率选择性还原为半胺醛(内羰基还原)或醛和胺(外羰基还原)。这些反应的机理方面已经在 DFT ab initio 水平上进行了研究,同时考虑了隐式溶剂效应以及热和压力校正到 298 K/1 atm。通过形成 σ 配合物和随后的四中心过渡态结构(1,2-迁移插入),反应从试剂到非常稳定的最终 Zr-oxo 中间体。插入步骤的能量屏障很大程度上取决于还原羰基上的辅助基团的性质。N-氨基甲酰基被还原为半缩氨酸,而 N-酰基在外羰基上反应。