Metal-Free Hydrogenation of Electron-Poor Allenes and Alkenes
作者:Blanca Inés、David Palomas、Sigrid Holle、Sebastian Steinberg、Juan A. Nicasio、Manuel Alcarazo
DOI:10.1002/anie.201205348
日期:2012.12.3
The poorer, the better: A metal‐free catalytic procedure for the reduction of electron‐poor allenes and alkenes has been developed. The method employs a frustrated Lewis pair based catalyst. 1,4‐Diazabicyclo[2.2.2]octane (DABCO)/B(C6F5)3 was shown to be the best combination in optimization studies.
越差越好:已开发出一种用于减少电子贫乏的烯和烯烃的无金属催化方法。该方法使用沮丧的路易斯对基催化剂。1,4-二氮杂双环[2.2.2]辛烷(DABCO)/ B(C 6 F 5)3被证明是优化研究的最佳组合。
The Development of the First Catalyzed Reaction of Ketenes and Imines: Catalytic, Asymmetric Synthesis of β-Lactams
作者:Andrew E. Taggi、Ahmed M. Hafez、Harald Wack、Brandon Young、Dana Ferraris、Thomas Lectka
DOI:10.1021/ja0258226
日期:2002.6.1
resulting from the development of a catalyzed reaction of ketenes (or their derived zwitterionic enolates) and imines. The products of these asymmetric reactions can serve as precursors to a number of enzyme inhibitors and drug candidates as well as valuable synthetic intermediates. We present a detailed study of the mechanism of the beta-lactam forming reaction with proton sponge as the stoichiometric
The synthesis of several electron poor allenes bearing electron withdrawing substituents is described and their use as Lewis acids in the field of frustrated Lewis pair (FLP) chemistry reported. At room temperature the combination of N-heterocyclic carbenes (NHC) with the allenes under study invariably afforded the corresponding Lewis adducts; however, at −78 °C this reaction is in most of the cases inhibited and kinetically induced organic FLPs are formed. Under these conditions the activation of S–S bonds in disulfides has been achieved in excellent yields.
Ring-transformation reactions of 4-imino-1,3-4H-oxazoles
作者:Gerrit L'abbé、Rik Destexhe
DOI:10.1039/c39850001614
日期:——
The 4-imino-1,3-4H-oxazole (3) undergoes ring-opening cycloaddition reactions with electrophilic heterocumulenes by way of an extended Boulton–Katritzky scheme.
[EN] SUBSTITUTED PYRAZINE COMPOUND AND PREPARATION METHOD THEREFOR AND USE THEREOF<br/>[FR] COMPOSÉ DE PYRAZINE SUBSTITUÉE ET PROCÉDÉ DE PRÉPARATION CORRESPONDANT ET SON UTILISATION<br/>[ZH] 一种取代吡嗪化合物、其制备方法和用途
申请人:SICHUAN KELUN BIOTECH BIOPHARMACEUTICAL CO LTD