Electroreductive crossed pinacol coupling of aromatic ketones with aliphatic ketones and aldehydes
作者:Naoki Kise、Yousuke Shiozawa、Nasuo Ueda
DOI:10.1016/j.tet.2007.04.050
日期:2007.6
The intermolecular crossed pinacol coupling of aromatic ketones with aliphatic aldehydes and ketones was effected by electroreduction in the presence of chlorotrimethylsilane. The best result was obtained using a Pb cathode in Bu4NPF6/THF. The electroreduction of aromatic 1,4-, 1,5-, and 1,6-diketones under the same conditions gave four-, five-, and six-membered 1,2-diols with trans-stereoselectivity
Unexpected Ti<sup>III</sup>/Mn-Promoted Pinacol Coupling of Ketones
作者:Miguel Paradas、Araceli G. Campaña、Rosa E. Estévez、Luis Álvarez de Cienfuegos、Tania Jiménez、Rafael Robles、Juan M. Cuerva、J. Enrique Oltra
DOI:10.1021/jo9005238
日期:2009.5.1
Titanocene(III) chemistry has emerged in the last decades as an indispensable tool in C-C bond-forming reactions. In this context, pinacol and related reactions allow the stereoselective synthesis of vicinal diols. In this work, we present new applications of these reactions using as starting materials aromatic ketones. Simple and smooth reaction conditions have been developed and have been applied for inter- and intramolecular processes. We also describe that although Cp2TiCl is usually used as a monoelectronic reducing agent, it can be also used as an efficient Lewis acid.
trans-Stereoselective intramolecular crossed pinacol coupling of aromatic 1,4-, 1,5-, and 1,6-diketones by electroreduction
作者:Naoki Kise、Yousuke Shiozawa、Nasuo Ueda
DOI:10.1016/j.tetlet.2004.08.120
日期:2004.10
Electroreduction of aromatic 1,4-, 1,5-, and 1,6-diketones in the presence of chlorotrimethylsilane and triethylamine gave four-, five-, and six-membered 1,2-diols with trans-stereoselectivity. (C) 2004 Elsevier Ltd. All rights reserved.