Tandem Amination/Cycloisomerization of Aryl Propargylic Alcohols with 2-Aminopyridines as an Expedient Route to Imidazo[1,2-a]pyridines
作者:Ping Liu、Chun-Lin Deng、Xinsheng Lei、Guo-qiang Lin
DOI:10.1002/ejoc.201101053
日期:2011.12
A new tandemroute leading to imidazo[1,2-a]pyridines has been explored through the direct amination of arylpropargylicalcohols with 2-aminopyridines and their subsequent intramolecular cycloisomerization. A ZnCl2/CuCl system has been developed to promote this transformation, which resulted in various imidazo[1,2-a]pyridines in moderate to good yields.
of terminal alkynes using aldehydes leading to ynones was developed. In contrast to the previous addition reactions of alkynes to aldehydes, which provide propargylic alcohols, the oxidative coupling proceeded exclusively to afford alkynyl ketones. The products were likely generated through an Oppenauer oxidation of the indium propargylic alkoxide species by excess amounts of aldehydes.
Iron-Catalyzed Direct Synthesis of Densely Substituted Benzofurans and Naphthopyrans from Phenolic Compounds and Propargylic Alcohols
作者:Feng-Quan Yuan、Fu-She Han
DOI:10.1002/adsc.201200804
日期:2013.2.1
propargylic alcohols in the presence of 5 mol% of iron(III) chloride hexahydrate (FeCl3⋅6 H2O) catalyst. On the other hand, pyran derivatives were obtained exclusively when tertiary propargylic alcohols were employed. Mechanistic studies revealed that presumably due to the discriminated steric effect of secondary and tertiary propargylic alcohols, the Fe-catalyzed Friedel–Crafts (F–C) reaction of phenols
Base-Mediated Cascade Rearrangements of Aryl-Substituted Diallyl Ethers
作者:Jolene P. Reid、Catherine A. McAdam、Adam J. S. Johnston、Matthew N. Grayson、Jonathan M. Goodman、Matthew J. Cook
DOI:10.1021/jo502403n
日期:2015.2.6
Two base-mediated cascade rearrangement reactions of diallyl ethers were developed leading to selective [2,3]-Wittig–oxy-Cope and isomerization–Claisen rearrangements. Both diaryl and arylsilyl-substituted 1,3-substituted propenyl substrates were examined, and each exhibits unique reactivity and different reaction pathways. Detailed mechanistic and computational analysis was conducted, which demonstrated