Asymmetric Synthesis of 3-Methyleneindolines via Rhodium(I)-Catalyzed Alkynylative Cyclization of <i>N</i>-(<i>o</i>-Alkynylaryl)imines
作者:Shi-Yi Yuan、Qi-Qi Yan、Dan Wang、Ting-Ting Dan、Long He、Cheng-Yu He、Wen-Dao Chu、Quan-Zhong Liu
DOI:10.1021/acs.orglett.1c01518
日期:2021.6.18
The first asymmetric synthesis of 3-methyleneindolines from alkynyl imines has been developed via a rhodium-catalyzed tandem process: regioselective alkynylation of the internal alkynes and subsequent intramolecular addition to the imines. The reaction proceeded with unconventional chemoselectivity and provided 3-methyleneindolines with good yields (up to 82% yield) and high enantioselectivities (up
Chromium(0)-Catalyzed Tandem Cyclization of α,β-Unsaturated Thioimidates Containing an Enyne Moiety
作者:Yusuke Karibe、Hiroyuki Kusama、Nobuharu Iwasawa
DOI:10.1002/anie.201201505
日期:2012.6.18
1‐azabicyclo[5.3.0]decane derivatives proceeds through 1,7‐electrocyclization of the zwitterionic intermediates that are formed in the cyclization of α,β‐unsaturated thioimidatescontaining an enynemoiety (see scheme). Furthermore 1,4‐addition of nucleophiles to α,β‐unsaturated carbene complex intermediates was also achieved.
A Sonogashira cross-coupling, nucleophilic substitution and elimination cascade reaction allows the synthesis of otherwise difficult to obtain linear dienynes, in moderate to high yields. Ionic liquids are suitable recyclable solvents for the reaction. This synthetic strategy opens new ways to prepare highly conjugated alkenes and alkynes.
TMSOTf-Catalyzed [4 + 2] Annulation of Ynamides and β-(2-Aminophenyl)-α,β-ynones for the Synthesis 2-Aminoquinolines
作者:Chaofan Qi、Xiaoxiao Shen、Wozheng Fang、Junbiao Chang、Xiao-Na Wang
DOI:10.1021/acs.orglett.4c00763
日期:——
A metal-free TMSOTf-catalyzed [4 + 2] annulation of ynamides with β-(2-aminophenyl)-α,β-ynones enables the regiospecific and facile assembly of 2-aminoquinoline frameworks. The catalyst TMSOTf presented a remarkable advancement compared to previously reported transition-metal catalysts. A wide range of 3-aryl/alkyl-substituted 2-aminoquinolines were generated in moderate to excellent yields due to
Intermolecular 1,5-dipolar cycloaddition reaction of tungsten-containing vinylazomethine ylide, generated from o-(alk-3-en-1-ynyl)phenylbenzaldimines and tungsten carbonyl complex, with ketene acetals proceeds efficiently to give azepino[1,2-a]indole derivatives in good yield. Formation of [5+2] or [3+2] cycloadducts can be controlled by an appropriate choice of dipolarophile.