Gold-Catalyzed Oxidative Cyclizations of {<i>o</i>-(Alkynyl)phenyl propargyl} Silyl Ether Derivatives Involving 1,2-Enynyl Migration: Synthesis of Functionalized 1<i>H</i>-Isochromenes and 2<i>H</i>-Pyrans
作者:Jidong Zhao、Wei Xu、Xin Xie、Ning Sun、Xiangdong Li、Yuanhong Liu
DOI:10.1021/acs.orglett.8b02380
日期:2018.9.7
A new and convenient strategy for the synthesis of functionalized 1H-isochromene and 2H-pyran derivatives based on gold-catalyzed oxidative cyclizations of o-(alkynyl)phenyl propargyl ether derivatives has been developed. The reaction proceeds via gold-catalyzed highly regioselective oxidation, followed by 1,2-migration of an enynyl group and nucleophlic addition. Isocoumarins were also constructed
Gold‐catalyzed [4+3]‐Annulations of Benzopyriliums with Vinyldiazo Carbonyls to Form Bicyclic Heptatriene Rings with Skeletal Rearrangement
作者:Antony Sekar Kulandai Raj、Rai‐Shung Liu
DOI:10.1002/adsc.202000292
日期:2020.6.15
annulatios are applicable to pyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl esters to increase their reaction significance. We postulate a mechanism involving an initial [4+2]‐cycloaddition between benzopyriliums and 3‐alkyl‐2‐diazo‐3‐vinyl carbonyl species, followed by formation of gold carbenes to induce a ringexpansion and group migrations.
Copper-catalyzed addition of water affording highly substituted furan and unusual formation of naphthofuran ring from 3-(1-alkenyl)-2-alkene-1-al
作者:Rathin Jana、Sunanda Paul、Anup Biswas、Jayanta K. Ray
DOI:10.1016/j.tetlet.2009.10.125
日期:2010.1
We have developed a novel one-pot reaction to generate highly substituted furan through the addition of water followed by oxidation and unusual cyclization to naphthofuran ring under the same reaction condition.
Tandem Addition/Cyclization Reaction of Organozinc Reagents to 2-Alkynyl Aldehydes: Highly Efficient Regio- and Enantioselective Synthesis of 1,3-Dihydroisobenzofurans and Tetrasubstituted Furans
作者:Zhuo Chai、Zheng-Feng Xie、Xin-Yuan Liu、Gang Zhao、Ji-De Wang
DOI:10.1021/jo800029m
日期:2008.4.1
The enantioselectiveaddition of organozinc reagents to some 2-alkynyl benzaldehydes and the subsequent regioselective cyclization step was performed in one pot to form chiral 1,3-dihydroisobenzofurans with good product yields and excellent regio- and enantioselectivities. In the case of 2-alkynylcycloalkene aldehydes, tetrasubstituted furans were obtained in good product yields through a 1, 5-hydride