An unprecedented Lewis acidcatalyzed, protection-free, and high-efficiency synthesis of valuable 3,4-dihydro-2H-2,4-methanochromans via cycloaddition of propargylic alkynols with 2-vinylphenol is described. This cycloaddition protocol, which tolerates a wide variety of functional groups, provides practical, versatile, and atom-economical access to a new class of appealing bridged-ring products in
本文描述了一种空前的路易斯酸,其通过炔丙基炔醇与2-乙烯基苯酚的环加成反应,催化了有价值的3,4-二氢-2 H -2,4-甲烷二甲基苯并没有保护性地进行了高效合成。该环加成方案可耐受多种官能团,以令人满意的收率提供实用,通用且经济实惠的途径来获得新型的有吸引力的桥环产品。与报道的桥环骨架合成反应条件相比,目前的反应条件是中性,温和且没有任何添加剂。
para-Toluenesulfonic Acid Catalyzed Synthesis of Indenes via a Tandem Friedel–Crafts Alkylation/Hydroarylation of Tertiary Propargylic Alcohols with Electron-Rich Arenes
A simple protocol to synthesize indenes efficiently by PTSA catalyzed tandem Friedel–Crafts alkylation/hydroarylation of tertiary propargylic alcohol with electron-rich arenes is described. The desired indenes were obtained regioselectively in good to very good yields under mild reaction conditions. The allene intermediate was isolated to get an insight into the mechanistic pathway of the indene forming
A facilesynthesis of highly substituted as well as conjugated unsymmetrical azines via the reaction of propargyl alcohols and isatin hydrazones in the presence of iodine is demonstrated under open to air. A series of unsymmetrical azines have been synthesized with excellent yields from simple and readily available starting materials in a complete stereoselective manner.
Reaction of Indole Carboxylic Acid/Amide with Propargyl Alcohols: [4 + 3]-Annulation, Unexpected 3- to 2- Carboxylate/Amide Migration, and Decarboxylative Cyclization
作者:Karuppu Selvaraj、Shubham Debnath、K. C. Kumara Swamy
DOI:10.1021/acs.orglett.9b01686
日期:2019.7.19
indole-2-carboxylic acids/amides form fused seven-membered lactones/lactams (oxepinoindolones/azepinoindolones) upon treatment with substituted propargyl alcohols using catalytic Cu(OTf)2. Decarboxylative cyclization of 1-methylindole-2- or indole-3-carboxylic acids with substituted propargyl alcohols under Lewis (for 1-methylindole-2-carboxylic acid) or Brønsted (for 1-methylindole-3-carboxylic acid) acid catalysis
Synthesis of 3-Alkyl- or 3-Allenyl-2-amidobenzofurans via Electrophilic Cyclization of <i>o</i>-Anisole-Substituted Ynamides with Carbocations
作者:Yulong Kong、Kezhi Jiang、Jian Cao、Lingzi Fu、Lian Yu、Guoqiao Lai、Yuming Cui、Ziqiang Hu、Guanhai Wang
DOI:10.1021/ol303474a
日期:2013.1.18
A facile carbocation-induced electrophilic cyclization reaction has been developed for the synthesis of 3-alkyl- or 3-allenyl-2-amidobenzofurans from o-anisole-substituted ynamides and diarylmethanol or 1,1-diarylprop-2-yn-1-ol.