Gold-Catalyzed Cycloisomerization of 1,6-Diyne Carbonates and Esters to 2,4a-Dihydro-1H-fluorenes
摘要:
A synthetic method to prepare 2,4a-dihydro-1H-fluorenes efficiently from gold(I)-catalyzed 1,2-acyloxy migration/cyclopropenation/Nazarov cyclization of 1,6-diyne carbonates and esters is described. The suggested reaction pathway provides rare examples of [2,3]-sigmatropic rearrangement in this class of compounds as well as the involvement of an in situ formed cyclopropene intermediate in gold catalysis. Experimental and ONIOM(QM:QM') [our own n-layered integrated molecular orbital and molecular mechanics(quantum mechanics quantum mechanics')] computational studies based on the proposed Au carbenoid species provide insight into this unique selectivity.
Gold-Catalyzed Cycloisomerization of 1,6-Diyne Carbonates and Esters to 2,4a-Dihydro-1<i>H</i>-fluorenes
作者:Weidong Rao、Ming Joo Koh、Dan Li、Hajime Hirao、Philip Wai Hong Chan
DOI:10.1021/ja4032727
日期:2013.5.29
A synthetic method to prepare 2,4a-dihydro-1H-fluorenes efficiently from gold(I)-catalyzed 1,2-acyloxy migration/cyclopropenation/Nazarov cyclization of 1,6-diyne carbonates and esters is described. The suggested reaction pathway provides rare examples of [2,3]-sigmatropic rearrangement in this class of compounds as well as the involvement of an in situ formed cyclopropene intermediate in gold catalysis. Experimental and ONIOM(QM:QM') [our own n-layered integrated molecular orbital and molecular mechanics(quantum mechanics quantum mechanics')] computational studies based on the proposed Au carbenoid species provide insight into this unique selectivity.
Indium(III) Chloride Catalyzed Conjugate Addition Reaction of Alkynylsilanes to Acrylate Esters
作者:Yan-li Xu、Ying-ming Pan、Pei Liu、Heng-shan Wang、Xiao-yan Tian、Gui-fa Su
DOI:10.1021/jo202628c
日期:2012.4.6
A novel and efficient procedure for the synthesis of δ,γ-alkynyl esters by the conjugateaddition of alkynylsilanes to acrylate esters in the presence of a catalytic amount of indium(III) chloride has been developed. This method provides a rapid and efficient access to substituted δ,γ-alkynyl esters.