InCl<sub>3</sub>-Catalyzed [3 + 2] CycloadditionReactions: A Facile Synthesis of<i>trans</i>-Dihydrobenzofuransand Substituted Cyclobutane Derivatives
作者:J. S. Yadav、B. V. Reddy、G. Kondaji
DOI:10.1055/s-2003-39175
日期:——
1,4-Benzoquinones undergo smoothly [3 + 2] cycloaddition reactions with electron rich alkenes in the presence of 10 mol% indium trichloride or 5 mol% iodine under mild conditions to afford the corresponding 2,3-dihydrobenzofurans in excellent yields with trans-selectivity. Similarly, methyl vinyl ketone reacts with electron rich olefins to produce substituited trans-cyclobutane derivatives.
PEG-400 as green reaction medium for Lewis acid-promoted cycloaddition reactions with isoeugenol and anethole
作者:Vladimir V. Kouznetsov、Diego R. Merchan Arenas、Arnold R. Romero Bohórquez
DOI:10.1016/j.tetlet.2008.03.049
日期:2008.5
A simple and efficient one-pot method for the synthesis of new 2,4-diaryl-1,2,3,4-tetrahydroquinolines using a three-component imino Diels-Alder cycloaddition between trans-isoeugenol or trans-anethole, anilines, and benzaldehyde in the presence of BF3 center dot OEt2 in PEG-400, a green and reusable solvent, has been developed. Also, BF3 center dot OEt2-catalyzed formal [3+2] cycloaddition reaction of tralls-isoeugenol or trans-anethole with 1,4-benzoquinone in PEG-400 to give dihydrobenzo[b]furan derivatives has been described. (C) 2008 Elsevier Ltd. All rights reserved.
Sustainable Chemical Synthesis of 2,3-Dihydrobenzofurans/1,2,3-Trisubstituted Indanes in Water Using a Permethylated β-Cyclodextrin-tagged NHC-Gold Catalyst
An environmentally friendly stereoselective synthesis of 2,3-dihydrobenzofurans and 1,2,3-trisubstituted indanes in water has been achieved by using a permethylated β-cyclodextrin-tagged N-heterocyclic carbene–gold complex. The gold catalyst can be recycled at least five times.