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.
expedient method was demonstrated for the synthesis of 3‐alkenyl‐3‐amino‐2‐oxindoles from readily available propargylic alcohols and isatin imines in the presence of BF3 ⋅ Et2O as a catalyst under open‐air atmosphere. The above reaction was time‐dependent and further extended to the one‐pot synthesis of highly substituted spiro‐indeneindolones via 1,3‐amino group migration/Friedel‐Crafts cyclization. This