Silica-supported HClO<sub>4</sub> promotes catalytic solvent- and metal-free O–H insertion reactions with diazo compounds
作者:Rafael Douglas C. Gallo、Antonio C. B. Burtoloso
DOI:10.1039/c8gc02574f
日期:——
employing rhodium acetate dimer, this method uses eco-friendly silica-supported HClO4 as the catalyst. Only 0.3 mol% of this Brønsted acid catalyst, that can also be recycled several times, is necessary to guarantee very good yields (up to 97%) in the O–H insertion reactions. Reaction set-up is simple and permitted the preparation of forty-three α-hydroxy and α-alkoxy esters/ketones in just 1 h and at room
Alternative Sm(II) Species-Mediated Cascade Coupling/Cyclization for the Synthesis of Oxobicyclo[3.1.0]hexane-1-ols
作者:Bingxin You、Mengmeng Shen、Guanqun Xie、Hui Mao、Xin Lv、Xiaoxia Wang
DOI:10.1021/acs.orglett.7b03613
日期:2018.2.2
The allylSmBr/HMPA/MsOH system has been found to be an efficient reagent for the "ester-alkene" coupling/cyclization cascade of readily available a-allyloxy esters. Oxobicyclo[3.1.0]hexane-1-ols were thus prepared in good to excellent yields and diastereoselectivities. Investigation on the mechanism suggested the possible existence of a new Sm(II) species, namely, CH3SO3SmBr, which resulted from the reaction between allylSmBr and MsOH and may be the actual SET reagent.