In the presence of anhydrous cerium(III) chloride, Grignardreagents react with Ketones to afford addition products in high yields, even though the substrates are susceptible to abnormal reactions with Grignardreagents alone.
Copper-catalyzed desymmetrization of prochiral 4,4-disubstituted cyclopentenes <i>via</i> a site-selective allylic oxidation: a concise total synthesis of untenone A
作者:Qingwen Gui、JuanJuan Wang、Sean Ng、Anja Dancevic、Timothy B. Wright、P. Andrew Evans
DOI:10.1039/c9cc01743g
日期:——
The desymmetrization of prochiral 4,4-disubstituted cyclopentenes via a site-selective copper-catalyzedallylic oxidation is described. This study provides a direct comparison of a series of known methods for allylic oxidation, and thus identifies ligand-free copper(I) iodide as the optimal catalyst for this particular process. Notably, this work offers a convenient approach to the preparation of γ-quaternary
The addition of Grignardreagents to ketones is significantly enhanced by cerium chloride with remarkable suppression of side reactions, particularly enolization. Some esters, which are prone to side reactions, also react readily with Grignardreagents in the presence of cerium chloride to give normal reaction products in reasonable to high yields.
Palladium-Catalyzed Hydroalkoxycarbonylation and Hydroxycarbonylation of Cyclopent-3-en-1-ols: Divergent Synthesis of Bridged Cyclic Lactones and β,γ-Unsaturated Carboxylic Acids
作者:Ming Chen、Yang Li、Zheng-Hui Guan
DOI:10.1021/acs.orglett.3c00498
日期:2023.4.21
report a palladium-catalyzed hydroalkoxycarbonylation and hydroxycarbonylation of cyclopent-3-en-1-ols to form bridged bicyclic lactones and β,γ-unsaturated carboxylic acid. The divergent reactivity of cyclopent-3-en-1-ols is mainly tuned by the palladium catalyst and ligands. The reaction occurs additive-free and has a broad substrate scope. Several valuable synthetic and medical intermediates are accessible