Background: Michael addition reaction is one of the most important and widely used reactions
for making carbon-carbon or carbon-hetero bonds in organic synthesis. The reaction involves
a facile attack of nucleophile to enone in a conjugated manner across a carbon-carbon double bond.
We herein report an expeditious camphor sulfonic acid-catalyzed Michael reaction for the synthesis
of different 3-substituted indole derivatives at room temperature. This method is convenient, environmentally
friendly and produces products in high yields.
Method: Commercially available camphor sulfonic acid is used as organo-catalyst to activate the reaction.
The newly synthesized compounds are characterized by using 1HNMR, 13C NMR and IR
Result: A highly substituted 3-indoyle carbonyl compounds has been synthesized in excellent yield
under very mild reaction conditions.
Conclusion: We developed an environmentally benign synthetic method to access novel synthesis of
substituted indoles under remarkably simple and high yielding reaction.