Rapid, robust, clean, catalyst-free synthesis of 2-halo-3-carboxyindoles
摘要:
A novel synthesis of 2-halo-3-carboxyindoles from 2-(2,2-dihalovinyl)anilines was discovered. Reaction conditions and substrate applicability were studied. Optimally, the reaction takes only minutes when these substrates are heated in DMSO at 120 degrees C in the presence of cesium carbonate. However, the reaction is robust and takes place at a wide range of temperatures, is tolerant of aqueous reaction conditions, and can be performed in a variety of polar solvent/carbonate base combinations where the limiting factor is base solubility. A wide range of substituents is tolerated on the 2-(2,2-dihalovinyl)anilines, and yields are generally high, requiring only acidic aqueous work-up to obtain pure products. No catalyst is required for the transformation. The mechanism is believed to involve initial formation of an alkynyl bromide intermediate followed by ring closure and carbon dioxide trapping, leading to product formation. (C) 2011 Elsevier Ltd. All rights reserved.
Rapid, robust, clean, catalyst-free synthesis of 2-halo-3-carboxyindoles
摘要:
A novel synthesis of 2-halo-3-carboxyindoles from 2-(2,2-dihalovinyl)anilines was discovered. Reaction conditions and substrate applicability were studied. Optimally, the reaction takes only minutes when these substrates are heated in DMSO at 120 degrees C in the presence of cesium carbonate. However, the reaction is robust and takes place at a wide range of temperatures, is tolerant of aqueous reaction conditions, and can be performed in a variety of polar solvent/carbonate base combinations where the limiting factor is base solubility. A wide range of substituents is tolerated on the 2-(2,2-dihalovinyl)anilines, and yields are generally high, requiring only acidic aqueous work-up to obtain pure products. No catalyst is required for the transformation. The mechanism is believed to involve initial formation of an alkynyl bromide intermediate followed by ring closure and carbon dioxide trapping, leading to product formation. (C) 2011 Elsevier Ltd. All rights reserved.
A structurally novel liverXreceptor (LXR) agonist (1) was identified from internal compound collection utilizing the combination of structure-based virtual screening and high-throughput gene profiling. Compound 1 increased ABCA1 gene expression by eightfold and SREBP1c by threefold in differentiated THP-1 macrophage cell lines. Confirmation of its agonistic activity against LXR was obtained in the
A new tandem coupling approach to synthesize 2-alkynyl indoles and benzofurans is described. This reaction utilizes easily accessible gem-dibromovinyl substrates and terminal alkynes and proceeds via Pd/C- and CuI-catalyzed tandem Ullman/Sonogashira couplings.
An efficient Pd(0)-catalyzed synthesis of 2-cyanoindoles from 2-gem-dihalovinylanilines is reported. Few methods have aimed to synthesize these scaffolds, which are found in many natural products and have high bioactivity. This protocol features a robust catalyst system utilizing Zn(TFA)(2) to prolong the catalytic activity. Additionally, the amount of cyanide in the reaction phase is minimized by taking advantage of the solubility of Zn(CN)(2) in a two-solvent mixture.
[EN] 2-VINYL INDOLES, PYRIDO AND AZEPINO INDOLE DERIVATIVES, 2-ALKYNYL INDOLES, 2-ALKYNYL BENZO[b]FURANS, THEIR PRECURSORS AND NOVEL PROCESSES FOR THE PREPARATION THEREOF<br/>[FR] 2-VINYLINDOLES, DÉRIVÉS PYRIDO ET AZÉPINOINDOLE, 2-ALCYNYLINDOLES, 2-ALCYNYLBENZO[b]FURANNES, LEURS PRÉCURSEURS ET LEURS NOUVEAUX PROCÉDÉS DE PRÉPARATION
申请人:LAUTENS MARK
公开号:WO2007134421A1
公开(公告)日:2007-11-29
[EN] The present invention relates to the preparation of 2-vinyl indoles from ortho-gem-dibromovinylaniline compounds and alkene reagents using a palladium pre-catalyst, a base, and, in some instances, a ligand or additive. The present invention also relates to the preparation of pyrido and azepino derivatives via a palladium-catalyzed tandem intramolecular Buchwald-Hartwig amination and Heck coupling reaction of appropriately functionalized ortho-gem-dibromovinylanilines. The present invention also relates to the preparation of 2-alkynyl indoles from ortho-gem-dibromovinylaniline compounds and alkyne reagents using a palladium pre-catalyst, a copper pre-catalyst, a base, and a ligand. Novel processes for the preparation of benzo[b]furan compounds are also disclosed, wherein the 2-alkynyl benzo[b]furans are prepared from ortho-gem-dibromovinylphenol compounds and alkyne reagents using a palladium pre-catalyst, a copper pre-catalyst, a base, and a ligand. [FR] La présente invention concerne la préparation de 2-vinylindoles à partir de composés ortho-gem-dibromovinylanilineet de réactifs alcène, préparation dans laquelle on utilise un pré-catalyseur à base de palladium, une base, et, parfois, un ligand ou un additif. La présente invention concerne également la préparation de dérivés pyrido et azépino par l'intermédiaire d'une réaction intramoléculaire tandem catalysée par le palladium d'amination de Buchwald-Hartwig et de couplage de Heck d'ortho-gem-dibromovinylanilines convenablement fonctionnalisés. La présente invention concerne également la préparation de 2-alcynylindoles à partir de composés ortho-gem-dibromovinylaniline et de réactifs alcyne effectuée en utilisant un pré-catalyseur à base de palladium, un pré-catalyseur à base de cuivre, une base et un ligand. La présente invention concerne également des nouveaux procédés de préparation de composés benzo[b]furanne, où les 2-alcynylbenzo[b]furannes sont préparés à partir de composés ortho-gem-dibromovinylphénol et de réactifs alcyne en utilisant un pré-catalyseur à base de palladium, un pré-catalyseur à base de cuivre, une base et un ligand.