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.
Zn(Salen)-Catalyzed Asymmetric Alkynylation of Ketones
作者:Tsutomu Katsuki、Bunnai Saito
DOI:10.1055/s-2004-829057
日期:——
An in situ generated Zncomplex of salen ligand 4 was found to serve as an efficient catalyst for asymmetric addition reaction of an alkynylzinc reagent to various ketones. For example, addition of phenylacetylene to 3,3-dimethyl-2-butanone using the Zncomplex as catalyst showed enantioselectivity as high as 91% ee.
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
Brønsted Acid Catalyzed Alkylation of Indoles with Tertiary Propargylic Alcohols: Scope and Limitations
作者:Roberto Sanz、Delia Miguel、Alberto Martínez、Mukut Gohain、Patricia García-García、Manuel A. Fernández-Rodríguez、Estela Álvarez、Félix Rodríguez
DOI:10.1002/ejoc.201001055
日期:2010.12
Junta de Castilla y Leon (BU021A09 and GR-172) and the Ministerio de Educacion y Ciencia (MEC) and FEDER (CTQ2007-61436/BQU and CTQ2009-09949/BQU) for financial support. D. M. and A. M. thank the MEC for MEC-FPU predoctoral fellowships. M. G. thanks the MEC for a "Young Foreign Researchers" contract (SB2006-0215). M. A. F.-R. and P. G.-G. also thank the MEC for "Ramon y Cajal" and "Juan de la Cierva"
Junta de Castilla y Leon (BU021A09 和 GR-172) 以及教育部长 (MEC) 和 FEDER (CTQ2007-61436/BQU 和 CTQ2009-09949/BQU) 提供财政支持。DM 和 AM 感谢 MEC 提供 MEC-FPU 博士前奖学金。MG 感谢 MEC 的“外国青年研究人员”合同 (SB2006-0215)。MAF-R。和PG-G。还要感谢 MEC 的“Ramon y Cajal”和“Juan de la Cierva”合同。
Synthesis of 3-Allenylindoles and 3-Dienylindoles by Brønsted Acid Catalyzed Allenylation of 2-Arylindoles with Tertiary Propargylic Alcohols
The Brønsted acid catalyzed direct nucleophilic substitution of tertiary propargylic alcohols with 2-aryl-substituted indoles has been studied. A competitive allenylation process takes place with appropriate substituents on the alkynol moiety. Starting from 2-arylindoles, new 3-allenyl and 3-dienylindole derivatives have been easily synthesized.