Stereospecific Electrophilic Fluorocyclization of α,β-Unsaturated Amides with Selectfluor
作者:Haiyang Fei、Zheyuan Xu、Hongmiao Wu、Lin Zhu、Hitesh B. Jalani、Guigen Li、Yao Fu、Hongjian Lu
DOI:10.1021/acs.orglett.0c00620
日期:2020.4.3
An efficient fluorocyclization of α,β-unsaturated amides through a formal halocyclization process is developed. The reaction proceeds undertransition-metal-freeconditions and leads to the formation of fluorinated oxazolidine-2,4-diones with excellent regio- and diastereoselectivity. The evaluation of the reaction mechanism based on preliminary experiments and density functional theory calculations
Oxidative Rearrangement of Tertiary Propargylic Alcohols
作者:Arantxa Rodríguez、Wesley Moran
DOI:10.1055/s-0032-1317711
日期:——
An oxidative rearrangement of tertiaryalcohols mediated by m-CPBA is described that generates tetrasubstituted alkenes with a carboxylic acid substituent. The mechanism of the reaction is proposed to proceed through epoxidation of the alkyne to form an oxirene that undergoes a 1,2-aryl shift.
A silver-catalyzed carbomagnesiation of alkynes with alkyl halides and Grignardreagents afforded alkenyl Grignardreagentsregioselectively, where the alkyl group of the alkyl halide, but not that of the Grignardreagent, was introduced into the alkyne. Application to δ-haloalkylacetylenes yielded cyclopentanes or a tetrahydrofuran containing an exo-methylene substituent via 5-exo-dig cyclization
Ni-Catalyzed Carboxylation of Unactivated Alkyl Chlorides with CO<sub>2</sub>
作者:Marino Börjesson、Toni Moragas、Ruben Martin
DOI:10.1021/jacs.6b04088
日期:2016.6.22
A catalytic carboxylation of unactivated primary, secondary, and tertiary alkylchlorides with CO2 at atmospheric pressure is described. This protocol represents the first intermolecular cross-electrophile coupling of unactivatedalkylchlorides, thus leading to new knowledge in the cross-coupling arena.
描述了未活化的伯、仲和叔烷基氯化物在大气压下与 CO2 的催化羧化。该协议代表了未活化烷基氯化物的第一个分子间交叉亲电偶联,从而导致交叉偶联领域的新知识。
Enantioselective Hydrogenation of Tetrasubstituted α,β‐Unsaturated Carboxylic Acids Enabled by Cobalt(II) Catalysis: Scope and Mechanistic Insights
established, asymmetric hydrogenation of challenging tetrasubstituted α,β‐unsaturatedcarboxylicacids is rarely reported. We demonstrate enantioselective hydrogenation of cyclic and acyclic tetrasubstituted α,β‐unsaturatedcarboxylicacids via cobalt(II) catalysis. This protocol showed broad substrate scope and gave chiral carboxylicacids in good yields with excellent enantiocontrol (up to 98 % yield and