The selective asymmetric hydrogenation of four-membered exo-α,β-unsaturated cyclobutanones has been achieved for the first time using RuPHOX-Ru as a catalyst, providing four-membered exo-cyclic chiral allylic alcohols in high yields and with up to 99.9% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C), and the resulting products can be transformed
使用RuPHOX-Ru作为催化剂,首次实现了四元外-α,β-不饱和环丁酮的选择性不对称加氢,以高收率和高达99.9%的产率提供了四元外环手性烯丙基醇。 ee。该反应可以以克级进行,具有相对较低的催化剂负载量(最高10000 S / C),并且所得产物可以转化为几个生物活性分子。
Proline and secondary amine co-catalyzed condensation of cyclobutanone with aldehydes: a facile access to 2-methylenecyclobutanones under near neutral conditions
作者:Lei Yu、Jie Luan、Lin Xu、Yuanhua Ding、Qing Xu
DOI:10.1016/j.tetlet.2015.09.088
日期:2015.10
Using L-proline catalyst, the useful building blocks 2-methylenecyclobutanones (2-MCBones) are now easily accessible in moderate to good yields through the condensation of the commercially available cyclobutanone with the abundant aldehydes. Compared with the literature reports, this methodology provides a direct synthesis of 2-MCBones from accessible starting materials and employs near neutral catalysts, which are stable to the acidic impurities in substrates. (C) 2015 Elsevier Ltd. All rights reserved.