A selective, efficient and environmentally friendly method for the oxidative cleavage of glycols
作者:Nuria García、Rubén Rubio-Presa、Patricia García-García、Manuel A. Fernández-Rodríguez、María R. Pedrosa、Francisco J. Arnáiz、Roberto Sanz
DOI:10.1039/c5gc02862k
日期:——
A catalytic methodology for the oxidativecleavage of vicinal diols is described as an advantageous alternative in terms of environmental impact to classical methods involving toxic oxidants. The novel strategy...
Light-enabled metal-free pinacol coupling by hydrazine
作者:Zihang Qiu、Hanh D. M. Pham、Jianbin Li、Chen-Chen Li、Durbis J. Castillo-Pazos、Rustam Z. Khaliullin、Chao-Jun Li
DOI:10.1039/c9sc03737c
日期:——
Efficientcarbon–carbonbondformation is of great importance in modern organic synthetic chemistry. The pinacol coupling discovered over a century ago is still one of the most efficient coupling reactions to build the C–C bond in one step. However, traditional pinacol coupling often requires over-stoichiometric amounts of active metals as reductants, causing long-lasting metal waste issues and sustainability
高效的碳-碳键形成在现代有机合成化学中非常重要。一个多世纪前发现的频哪醇偶联仍然是一步构建 C-C 键的最有效偶联反应之一。然而,传统频哪醇偶联通常需要过量化学计量的活性金属作为还原剂,从而导致长期存在的金属废料问题和可持续性问题。一个巨大的科学挑战是设计一种无金属的频哪醇偶联反应方法。在这里,我们描述了一种光驱动频哪醇耦合协议,不使用任何金属,但使用 N 2 H 4,用作清洁的非金属氢原子转移 (HAT) 还原剂。在这种转化中,只有无痕无毒的N 2和H 2气体作为副产物产生,具有相对广泛的芳香酮范围和良好的官能团耐受性。对该机制的实验和计算研究表明,这种新颖的频哪醇偶联反应是通过光激发酮和 N 2 H 4之间的 HAT 过程进行的,而不是金属还原剂的常见单电子转移 (SET) 过程。
Mg/Triethylammonium Formate: A Useful System for Reductive Dimerization of Araldehydes into Pinacols; Nitroarenes into Azoarenes and Azoarenes into Hydrazoarenes
作者:M. GEETA PAMAR、P. GOVENDER、K. MUTHUSAMY、RUI W. M. KRAUSE、H.M. NANJUNDASWAMY
DOI:10.13005/ojc/290316
日期:2013.9.30
of triethylammoniumformate in the presence of magnesium for the efficient intermolecular pinacol coupling using MeOH as solvent. Various aromatic carbonyls underwent smooth reductive coupling to give the corresponding 1,2-diols. A series of azo compounds were obtained by the reductive coupling of nitroaromatics while azo compounds were reduced to the corresponding hydrazoarenes by this system. There
A Convenient Electrochemical Method for Conversion of 4-Haloacetophenone to 1-(4-Halophenyl)ethanol
作者:Yoshikazu Ikeda
DOI:10.1246/cl.1990.1719
日期:1990.9
In the presence of a catalytic amount of Sb(III), 4-fluoro-, 4-chloro-, 4-bromo-, and 4-iodoacetophenone were converted into the corresponding 1-(4-halophenyl)ethanols by an electrochemical method (−3.7 mA/cm2, 6F/mol, Pb cathode). Each alcohol yielded 91, 94, 98, and 94%, respectively.
Herein, we successfully achieve this goal by employing a recyclable solid acid/ionicliquidcatalyst system. The dehydration of alkyl- and cycloalkyl-derived diols in an Amberlyst-15/[Emim]Cl system afforded the corresponding 1,3-dienes in good yields, while a Nafion/[Emim]Cl system was demonstrated to be a better catalyst system for the dehydration of aryl-substituted substrates. Our protocol features