Copper-catalysed benzofuran synthesis: developing aryl bromide–alkenyl triflates as general heterocycle precursors
摘要:
A range of conjugated aryl bromide-alkenyl triflates, previously described as indole precursors, are efficiently converted to the corresponding benzofurans when treated with CuI/TMEDA and potassium hydroxide. (C) 2007 Elsevier Ltd. All rights reserved.
Dehydrative C–H Alkylation and Alkenylation of Phenols with Alcohols: Expedient Synthesis for Substituted Phenols and Benzofurans
作者:Dong-Hwan Lee、Ki-Hyeok Kwon、Chae S. Yi
DOI:10.1021/ja302710v
日期:2012.5.2
well-defined cationic Ru-H complex catalyzes the dehydrative C-H alkylation reaction of phenols with alcohols to form ortho-substituted phenol products. Benzofuran derivatives are efficiently synthesized from the dehydrative C-H alkenylation and annulation reaction of phenols with 1,2-diols. The catalytic C-H coupling method employs cheaply available phenols and alcohols, exhibits a broad substrate scope, tolerates
Cascade Palladium-Catalyzed Direct Intramolecular Arylation/Alkene Isomerization Sequences: Synthesis of Indoles and Benzofurans
作者:Myriam Yagoubi、Ana C. F. Cruz、Paula L. Nichols、Richard L. Elliott、Michael C. Willis
DOI:10.1002/anie.201004097
日期:2010.10.18
One route, two cycles: A palladium‐catalyzed intramoleculardirectarylation reaction combined with an isomerization step provided a straightforward synthetic route to both indoles and benzofurans (see scheme). Isolation and functionalization of intermediate alkene isomers allowed the formation of variants having substituents remote from the core.
Palladium-catalysed intramolecular enolate O-arylation and thio-enolate S-arylation: synthesis of benzo[b]furans and benzo[b]thiophenes
作者:Michael C. Willis、Dawn Taylor、Adam T. Gillmore
DOI:10.1016/j.tet.2006.05.004
日期:2006.12
Enolates derived from alpha-(ortho-haloaryl)-substituted ketones undergo palladium-catalysed C-O bond formation to deliver benzofuran products in good yield. A catalyst generated from Pd-2(dba)(3) and the ligand DPEphos effects the key bond formation to deliver a variety of substituted products from both cyclic and acyclic precursors. The analogous thio-ketones undergo C-S bond formation using identical reaction conditions and are converted to benzothiophene products. A cascade sequence that produces the required a-aryl ketones in situ has also been developed, although the substrate scope is more restricted. (c) 2006 Elsevier Ltd. All rights reserved.
Palladium-Catalyzed Intramolecular <i>O</i>-Arylation of Enolates: Application to Benzo[<i>b</i>]furan Synthesis
作者:Michael C. Willis、Dawn Taylor、Adam T. Gillmore
DOI:10.1021/ol047993g
日期:2004.12.1
A catalyst generated from Pd-2(dba)(3) and the ligand DPEphos effects intramolecular C-O bond formation between enolates and aryl halides in the conversion of 1-(2-haloaryl)ketones directly into the corresponding benzofurans. Both cyclic and acyclic ketones are efficient substrates. Thio ketones can also be employed allowing the preparation of the corresponding benzothiophenes.