<i>In Situ</i> Formed Acetal-Facilitated Synthesis of Substituted Indene Derivatives from <i>o</i>-Alkenylbenzaldehydes
作者:Seetharaman Manojveer、Rengarajan Balamurugan
DOI:10.1021/acs.orglett.5b01695
日期:2015.7.17
A new protocol has been developed for the synthesis of indene derivatives, in a diastereoselective manner from,o-alkenylbenzaldehydes and enolizable ketones hi the presence of trimethyl orthoformate and catalytic triflic acid. This method involves tandem in situ formed acetal-assisted Claisen-Schmidt condensation followed by 5-exo-trig cyclization/Michael addition in one-pot. It has also been shown that the chalcones derived from o-alkenylbenzaldehydes and ketones can effectively be transformed into indene derivatives in the presence of TfOH catalyst alone.
Organoselenium-Catalyzed Aza-Wacker Reactions: Efficient Access to Isoquinolinium Imides and an Isoquinoline N-Oxide
作者:Huimin Li、Lihao Liao、Xiaodan Zhao
DOI:10.1055/s-0039-1690103
日期:2019.9
organoselenium-catalyzed aza-Wacker reaction of olefinic hydrazones and an oxime to form isoquinolinium imides and an isoquinoline N-oxide is developed. This transformation involves a direct intramolecular C–H amination using hydrazones and an oxime as imine-type nitrogen sources. This work not only provides a new approach for the construction of isoquinoline derivatives, but also expands the scope of nitrogen
Iodine‐Catalyzed Cascade Reaction of 2‐Styrylbenzaldehydes with Indoles in the Synthesis of 1<i>H</i>‐Indenes via 4π‐Electrocyclization
作者:Sundaram Suresh、Hao‐Yu Tsai、Xin‐Lun Han、Veerababurao Kavala、Sowndarya Palla、Ching‐Fa Yao
DOI:10.1002/adsc.202301412
日期:2024.3.19
A cascade reaction between 2-styrylbenzaldehydes and indoles has been developed for the synthesis of 1H-indenes. An iodine-catalyzed nucleophilic addition of indoles to an aldehyde group of 2-styrylbenzaldehydes leads to the formation of carbocation intermediates that undergo 4π-electrocyclization to give indenes with a trisubstituted double bond. These indenes are transformed into thermodynamically