描述了一种新颖高效的吡啶并[3',2':4,5]吡咯并[1,2- c ]嘧啶系统的合成,该系统是海洋生物碱的variolin家族的杂环核心。该路线涉及3-溴-2-(溴甲基)吡咯并[2,3- b ]吡啶与甲苯磺酰基甲基异氰化物(TosMIC)在相转移条件下的反应。通过TosMIC与溴甲基吲哚,溴甲基苯并咪唑和溴甲基吡唑的反应,该空前的反应还用于合成一系列新的甲氧基羰基氮杂嘧啶。5-溴-7-甲氧基羰基吡啶并[3',2':4,5]吡咯并[1,2- c的水解和脱羧通过该杂环化方法获得的嘧啶嘧啶并在C5位置安装嘧啶部分,这为完成variolin B的全合成提供了另一种方法。
描述了一种新颖高效的吡啶并[3',2':4,5]吡咯并[1,2- c ]嘧啶系统的合成,该系统是海洋生物碱的variolin家族的杂环核心。该路线涉及3-溴-2-(溴甲基)吡咯并[2,3- b ]吡啶与甲苯磺酰基甲基异氰化物(TosMIC)在相转移条件下的反应。通过TosMIC与溴甲基吲哚,溴甲基苯并咪唑和溴甲基吡唑的反应,该空前的反应还用于合成一系列新的甲氧基羰基氮杂嘧啶。5-溴-7-甲氧基羰基吡啶并[3',2':4,5]吡咯并[1,2- c的水解和脱羧通过该杂环化方法获得的嘧啶嘧啶并在C5位置安装嘧啶部分,这为完成variolin B的全合成提供了另一种方法。
Carboxylation of NH/CH Bonds Using N-Heterocyclic Carbene Copper(I) Complexes
作者:Ine I. F. Boogaerts、George C. Fortman、Marc R. L. Furst、Catherine S. J. Cazin、Steven P. Nolan
DOI:10.1002/anie.201004153
日期:2010.11.8
Greenhouse gas makes good: A simple copper‐mediated protocol has been developed where NH or CH bonds can be directly functionalized using an easily prepared catalyst. The novel [1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]copper(I) hydroxide, [Cu(IPr)(OH)], permits the facile activation and carboxylation of NH and CH bonds with pKa values of less than 27.7 (see scheme).
温室气体有益:已开发出一种简单的铜介导方案,其中可以使用易于制备的催化剂将NH或CH键直接官能化。新颖的[1,3-双(2,6-二异丙基苯基)咪唑-2-亚基]铜(I)氢氧化,[铜(IPR)(OH)],允许容易的激活和羧化N中的 H和13 C H键的p K a 值小于27.7(请参阅方案)。
CARBOXYLATION CATALYSTS
申请人:Nolan Steven P.
公开号:US20130085276A1
公开(公告)日:2013-04-04
The use of a complex of the form Z—M—OR in the carboxylation of a substrate is described. The group Z is a two-electron donor ligand, M is a metal and OR is selected from the group consisting of OH, alkoxy and aryloxy. The substrate may be carboxylated at a C—H or N—H bond. The metal M may be copper, silver or gold. The two-electron donor ligand may be a phosphine, a carbene or a phosphite ligand. Also described are methods of manufacture of the complexes and methods for preparing isotopically labelled caboxylic acids and carboxylic acid derivatives.
On the reactivity of imidazole carbamates and ureas and their use as esterification and amidation reagents
作者:Stephen T. Heller、Richmond Sarpong
DOI:10.1016/j.tet.2011.09.057
日期:2011.11
The optimization, substrate scope, and mechanism of esterification and amidation of carboxylic acids mediated by imidazole-based reagents are discussed. The innate reactivity of carbonylimidazole reagents with a range of nucleophiles is also explored. New reagents developed for the synthesis of alpha,beta-unsaturated esters are described, as are reagents for the preparation of tertiary amides directly from carboxylic acids. (C) 2011 Elsevier Ltd. All rights reserved.