Catalysis of Enantioselective [2+1]-Cycloaddition Reactions of Ethyl Diazoacetate and Terminal Acetylenes Using Mixed-Ligand Complexes of the Series Rh<sub>2</sub>(RCO<sub>2</sub>)<i><sub>n</sub></i> (L*<sub>4</sub><sub>-</sub><i><sub>n</sub></i>). Stereochemical Heuristics for Ligand Exchange and Catalyst Synthesis
作者:Yan Lou、Travis P. Remarchuk、E. J. Corey
DOI:10.1021/ja052254w
日期:2005.10.1
mixed Rh(2)(II) complexes containing bridging acetate and R,R-diphenyl-N-triflylimidazolidinone (DPTI) ligands (1, 2, and 9-19), and their function as enantioselective catalysts for the conversion of ethyldiazoacetate and terminal acetylenes to chiral cyclopropenes. Of these catalysts, 1 and 10 functioned with the highest enantioselectivity, in accord with a mechanistic model in which one of the ligand
Conformational preferences of sterically congested 2-imidazolidinone using X-ray analysis and computational studies. Part 1: Trans-1-acetyl-4,5-di-tert-butyl-2-imidazolidinone
作者:Alaa A.-M. Abdel-Aziz、Mohamed A. Al-Omar、Adel S. El-Azab、Takehisa Kunieda
DOI:10.1016/j.molstruc.2010.01.061
日期:2010.4
bonding. The conformationalanalysis of the s - transoid 2a and 2b was performed by molecular mechanic, and showed the occurrence of one minimum for each molecule. Moreover RM1 semi-empirical and DFT/B3LYP calculations were applied to investigate the conformational preferences of the trans -1-acetyl-4,5-di- tert -butyl-2-imidazolidinone 2 and to correlate between calculated conformations and the structure
摘要 反式-1-乙酰基-4,5-二叔丁基-2-咪唑烷酮 2 [C 13 H 24 N 2 O 2 : MF = 240.34, 单斜晶系, P2 1 /c (# 14) , a = 12.313(4) A , b = 15.090(2) A, c = 16.246(2) A, β = 98.33(1)°, V = 2986.8(9) A 3 , Z = 8, D 计算= 1.069 g/cm 3 , μ (Cu-Kα) = 5.74 cm -1 , F 000 = 1056.00, T = 25.0 °C, R = 0.040] 被确定,并证实了 s - transoid 2a 的两个分子的出现和 2b 由两个氢键连接在一起。晶体内聚力由分子间氢键网络确保。s-transoid 2a 和 2b 的构象分析是通过分子力学进行的,并显示每个分子出现一个最小值。此外,应用 RM1 半经验和 DFT/B3LYP
Unusual N-acylation of sterically congested trans-4,5-disubstituted 2-imidazolidinones: remarkably facile CC bond formation
Stericallycongested trans-4,5-di-tert-butyl-2-imidazolidinone (DTBIm) and trans-4,5-di-(1-adamantyl)-2-imidazolidinone (DAIm), which are prepared from the parent 1,3-dihydro-2-imidazolone, undergo an unusual N-acylation reaction with acyl chlorides in the presence of organic amines to give the 3-oxoacyl derivatives.