A Brønsted acid catalyzed C3-selective tert-alkylation of indoles using tertiary propargylic and benzylic alcohols has been developed. New C3-propargylated indole derivatives with a quaternary carbon at the propargylic position have been efficiently synthesized. Reactions were performed in air with undried solvents, and water was the only side product of the process.
Brønsted acid−catalyzed synthesis of tetrasubstituted allenes and polysubstituted 2H-chromenes from tertiary propargylic alcohols
作者:Natalia Cabrera-Lobera、Noelia Velasco、Roberto Sanz、Manuel A. Fernández-Rodríguez
DOI:10.1016/j.tet.2019.05.023
日期:2019.8
A practical and environmentally benign Brønstedacid−catalyzed protocol for the preparation of all-carbon tetrasubstituted allenes, consisting in the direct SNˈ addition of tri- or dimethoxy arenes or allyltrimethylsilane to tertiary propargylic alcohols, has been developed. In addition, a straightforward synthesis of densely substituted 2H-chromenes by metal-free tandem allenylation/heterocyclization
Ytterbium(III) Triflate Catalyzed Tandem Friedel−Crafts Alkylation/Hydroarylation of Propargylic Alcohols with Phenols as an Expedient Route to Indenols
作者:Xiaoxiang Zhang、Wan Teng Teo、Philip Wai Hong Chan
DOI:10.1021/ol901981s
日期:2009.11.5
A method to prepare indenols efficiently by ytterbium(III) triflate catalyzed tandem Friedel−Crafts alkylation/hydroarylation of propargylic alcohols with phenols is described. The reaction was accomplished in moderate to excellent yields and regioselectivity under mild conditions and offers a straightforward and convenient one step synthetic route to bioactive indenols and its derivatives.
Waste-Free Catalytic Propargylation/Allenylation of Aryl and Heteroaryl Nucleophiles and Synthesis of Naphthopyrans
作者:J. McCubbin、Costa Nassar、Oleg Krokhin
DOI:10.1055/s-0030-1260146
日期:2011.10
pyrroles, as well as methoxy-substituted benzenes and naphthalenes. Reaction with 2-naphthol affords substituted naphthopyrans as products. Preliminary evidence suggests a Friedel-Crafts-like substitution mechanism, which occurs via an in situ generated carbocation. organocatalysis - boronic acids - propargylic alcohols - Friedel-Craftsreaction
Rhodium-Catalyzed and Chiral Zinc Carboxylate-Assisted Allenylation of Benzamides via Kinetic Resolution
作者:Ruxia Mao、Yanliang Zhao、Xiaohan Zhu、Fen Wang、Wei-Qiao Deng、Xingwei Li
DOI:10.1021/acs.orglett.1c02398
日期:2021.9.17
In this work, kinetic resolution of tertiary propargyl alcohols as an allenylating reagent has been realized via rhodium(III)-catalyzed C–H allenylation of benzamides. The reaction proceeded efficiently under mild conditions, and both the allenylated products and the propargyl alcohols were obtained in high enantioselectivities with an s-factor of up to 139. The resolution results from bias of the