Montmorillonite K10: Catalyst for Friedel–Crafts Alkylation of Indoles and Pyrrole with Nitroalkenes Under Solventless Conditions

Abstract

Montmorillonite K10 was found to catalyze the Michael addition of indoles or pyrrole with nitroalkenes efficiently under solventless condition. The short reaction time, simple workup, and excellent yields were noteworthy. The green catalyst could be reused for three runs without considerable variation in yield.

Keywords:

• Alkylation
• heterogenous catalysis
• indole
• montmorillonite K10
• nitroalkene

ACKNOWLEDGMENTS

We thank the National Natural Science Foundation of China (No. 20772088) and the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No. 08KJD150011) for the financial support.

Notes

^a Reaction conditions: indole 1.0 mmol, β-nitrostyrene 1.1 mmol, oil bath heating at 60 °C.

^b Isolated yield.

^c Performed at room temperature.

^a Reaction conditions: indole 1.0 mmol, β-nitrostyrene 1.1 mmol, oil bath heating at 60 °C.

^b Isolated yield.

^c The reaction was carried out at room temperature.

^a Reaction conditions: pyrrole 1.5 mmol, β-nitrostyrene 1.0 mmol, oil bath heating at 60 °C.

^b Isolated yield.

^c The reaction was carried out at room temperature.

^a Reaction conditions: indole 1.0 mmol, β-nitrostyrene 1.1 mmol, oil bath heating at 60 °C.

^b Isolated yield.