4-HO-TEMPO-Catalyzed Redox Annulation of Cyclopropanols with Oxime Acetates toward Pyridine Derivatives
作者:Jun-Long Zhan、Meng-Wei Wu、Dian Wei、Bang-Yi Wei、Yu Jiang、Wei Yu、Bing Han
DOI:10.1021/acscatal.9b00832
日期:2019.5.3
for the synthesis of pyridines through the annulation of cyclopropanols and oxime acetates has been developed. This protocol features good functional group tolerance and high chemoselectivity and also promises to be efficient for the late-stage functionalization of skeletons of drugs and natural products. Mechanism studies indicate that the reaction involves the in situ generated α,β-unsaturated ketones
opening/alkynylation of cyclopropanol by employing inexpensive and commercially available terminal alkyne is developed. The reactions proceeded efficiently to afford synthetically useful alk-4-yn-1-ones in moderate to good yields with good functional group tolerance. Control experiments showed that the reaction presumably proceeds via the formation of intermediates of copper homoenolate and/or alkynylcopper
Rh-Catalyzed cascade C–H activation/C–C cleavage/cyclization of carboxylic acids with cyclopropanols
作者:Siqi Wang、Erfei Miao、Hao Wang、Bichao Song、Wei Huang、Weibo Yang
DOI:10.1039/d1cc01778k
日期:——
Merging both C–H and C–C activation in a tandemprocess is a marked challenge. A novel Rh(III)-catalyzed C–H activation/ring opening C–C cleavage/cyclization of carboxylic acids with cyclopropanols was developed for the synthesis of 3-substituted phthalides and α,β-butenolides. This reaction displays excellent functional group tolerance with respect to both carboxylic acids and cyclopropanols and features
Stereoselective Iron-Catalyzed Alkylation of Enamides with Cyclopropanols via Oxidative C(sp<sup>2</sup>)–H Functionalization
作者:Xing Zhang、Tian-Ming Yang、Lu-Min Hu、Xu-Hong Hu
DOI:10.1021/acs.orglett.2c03563
日期:2022.12.2
Established herein is a radical-mediated C–H alkylation of enamides with cyclopropanols. An environmentally benign catalytic system with iron salt and air is used to permit the oxidative coupling process. The protocol demonstrates a broad substrate scope, allowing the stereoselective synthesis of alkylated enamides. The value of this strategy is further reflected by late-stage diversification of complex
Palladium-catalyzed coupling of amides and cyclopropanols for the synthesis of γ-diketones
作者:Lili Fang、Shuqi Jia、Shuaixin Fan、Jin Zhu
DOI:10.1039/d3cc02888g
日期:——
method has been developed for the coupling of amides and cyclopropanols to γ-diketones, through simultaneous C–N and C–C activation. Heteroatom ligand exchange and heteroatom-to-carbon ligation mode switching enable the achievement of molecular cross-coupling in an amide N-atom structural context-dependent manner, avoiding any stoichiometric organometallic reagent or base.