Boric Acid / Glycerol as an Efficient Catalyst for Synthesis of Thiomorpholine 1,1-Dioxide by Double Michael Addition Reaction in Water

Abstract

Thiomorpholine 1,1-dioxides were prepared with double Michael addition reaction of aromatic amines to divinyl sulfone catalyzed by boric acid / glycerol in water. This catalyst system was also used for the Michael addition reaction of aromatic amines to electron-deficient alkenes. The reaction is simple and green and gives good to excellent yields.

GRAPHICAL ABSTRACT

Keywords:

• Aromatic amines
• boric acid
• Michael addition
• thiomorpholine 1,1-dioxide
• water

ACKNOWLEDGMENTS

We are grateful to the Research Council of Sharif University of Technology for financial support. We also thank the Faculty of Chemistry of Tarbiat Moallem University for supporting this work.

Notes

^a Isolated yield.

^b Reaction condition: aromatic (3 mmol), divinyl sulfome (3 mmol), boric acid (30 mol%), glycerol (2–3 drops), and water (5 mL).

^a Isolated yield.

^b Reaction condition: aromatic (3 mmol), electron-deficient alkenes (5 mmol), boric acid (30 mol%), (2–3 drops), and water (5 mL).

^c The yields in parentheses are for the the bis-adduct. References are given for the known compounds.