Palladium-Catalyzed Tandem Reactions via Allene Intermediates for the Rapid Synthesis of a Fused Indenone-Indole
Shugao Zhu1, Yuxuan Fang1, Yu Xin1
1School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, P. R. China.
Abstract:
A palladium-catalyzed tandem reaction of 1-(2-iodophenyl)-3-arylprop-2-yn-1-ones and 1-(2-azidophenyl)propargyl ethers is developed to provide the rapid construction of a fused polycyclic indenone-indole scaffold under mild conditions. The reaction proceeds via a highly ordered process involving Sonogashira coupling, propargyl-allenyl isomerization, allene-azide cycloaddition, denitrogenation, and diradical coupling. The proposed reaction mechanism is supported by experimental and computational studies.
Related Concept Videos
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Cycloaddition Reactions: Overview
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is...
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...


