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
An unprecedented Lewisacidcatalyzed, high-efficiency synthesis of valuable 2-(quinolin-2-yl)prop-2-en-1-ones via dehydrogenative coupling of propargylic alkynols with quinoline N-oxides is described. This protocol, which tolerates a broad range of functional groups, provides a straightforward pathway to the products 2-(quinolin-2-yl)prop-2-en-1-one scaffolds in satisfactory yields. The conversion
Zn(OTf)<sub>2</sub>-Catalyzed Formal [3 + 3] Cascade Annulation of Propargylic Alcohols with 2-Aminochromones: Accessing the Chromeno[2,3-<i>b</i>]pyridines
作者:Pei Tong、Zhou Sun、Shutao Wang、Yuan Zhang、Ying Li
DOI:10.1021/acs.joc.9b02120
日期:2019.11.1
A Zn(OTf)2-catalyzed formal [3 + 3] cascade annulation strategy for the synthesis of functionalized chromeno[2,3-b]pyridines has been developed using propargylicalcohols and 2-aminochromones as the substrates. The protocol provides a convenient and atom-economical method of accessing a broad range of chromeno[2,3-b]pyridine derivatives in excellent yields with good functional-group tolerance. The
Lewis Acid Catalyzed Cascade Reactions of Diarylvinylidenecyclopropanes and 1,1,3-Triarylprop-2-yn-1-ols or Their Methyl Ethers
作者:Min Shi、Liang-Feng Yao
DOI:10.1002/chem.200800421
日期:2008.9.26
The reactions of vinylidenecyclopropanes 1 with 1,1,3-triarylprop-2-yn-1-ols or their methyl ethers 2 in the presence of a Lewisacid selectively produce 4-dihydro-1H-cyclopenta[b]naphthalene derivatives 3 or 1,2,3,8-tetrahydrocyclopenta[a]indene derivatives 4 depending on the substituents on the cyclopropane. Good to high yields are obtained under mild conditions. A plausible cascade Meyer-Schuster
An unambiguous and precise method for the synthesis of 3,1-benzoxathiin-4-ones/1,3-benzodioxin-4-ones by the reaction of propargylic alcohols and salicylic/thiosalicylic acids under a catalyst-free and open-air atmosphere is described.