Regioselective Prenylation of Phenols by Palladium Catalyst: Syntheses of Prenylphenols and Chromans
摘要:
The palladium-catalyzed coupling reaction of iodophenols (1) with 2-methyl-3-butyn-2-ol gave alkynylphenols (2). Catalytic hydrogenation of 2 over Raney nickel and the subsequent dehydration of the resultant alkylphenols (3) gave regioselectively the desired prenylphenols (4). Dehydration of alkylphenols (3f-h) gave chromans (7).
Diverse Alkanones by Catalytic Carbon Insertion into the Formyl C−H Bond. Concise Access to the Natural Precursor of Achyrofuran
作者:Andrew J. Wommack、David C. Moebius、Austin L. Travis、Jason S. Kingsbury
DOI:10.1021/ol9010932
日期:2009.8.6
Over a century ago, the first reactions of diazomethane with aldehydes delivered methyl ketones. In the interim, aldehydes have been homologated with trimethylsilyldiazomethane, diazoacetates, and aryldiazomethanes, on rare occasion with catalysis. This work describes a mild procedure for convergent ketone assembly from nonstabilized diazoalkanes, including examples of chiral ketone synthesis with
Gold(I)-catalyzed intermolecular hydroarylation of allenes with nucleophilic arenes: scope and limitations
作者:Michael A. Tarselli、Ann Liu、Michel R. Gagné
DOI:10.1016/j.tet.2008.10.110
日期:2009.2
The addition of nucleophilic methoxyarenes to allenes proceeds at room temperature in dichloromethane with a catalytic amount of phosphite-gold(I) precatalyst and silver additive. The addition is regioselective for the allene terminus, and generates E-allylation products without the need for prefunctionalization of the synthons as organometallics or allyl bromides. Coordinating heteroaromatics and
AN EFFICIENT REGIO- AND STEREOSPECIFIC ALKENYLATION OF PHENOLIC ETHERS BY PRENYL AND GERANYL DIISOPROPYL PHOSPHATES
作者:Shuki Araki、Shin-ichi Manabe、Yasuo Butsugan
DOI:10.1246/cl.1982.797
日期:1982.6.5
Prenyl and geranyl diisopropyl phosphates readily alkenylate a variety of phenolic ethers regio- and stereospecifically without any appreciable side reactions.
异戊二烯基和香叶基二异丙基磷酸酯很容易使各种酚醚区域和立体特异性地烯基化,而没有任何明显的副反应。
Iron-mediated aromatic allylation
作者:Janice W. Dieter、Zhong Li、Kenneth M. Nicholas
DOI:10.1016/s0040-4039(00)96742-x
日期:1987.1
Sulfonium salts as prenyl, geranyl, and isolavandulyl transfer agents towards benzoylphloroglucinol derivatives
In search for new methods aiming biomimetic synthesis of polyprenylated acylphloroglucinols (PPAPs), we now report the results of an evaluation of sulfonium salts as prenyl, geranyl, and isolavandulyl transfer agents towards benzoylphloroglucinol derivatives, in neutral conditions. As a result, conditions were found for rather efficient C-prenylation of these compounds. The corresponding trimethyl ether gave the best results, but the reaction was accompanied by a deacylation process. Geranyl transfer was also observed, but in low yield, and, interestingly, an isolavandulyl group could be introduced with an appreciable yield. (c) 2007 Elsevier Ltd. All rights reserved.