Dramatically Accelerated Addition Under Solvent-Free Conditions: An Efficient Synthesis of (E)-1,2,4-Triazole-Substituted Alkenes from Baylis–Hillman Acetates

Abstract

The addition of 1,2,4-triazole to Baylis–Hillman acetates mediated by Et₃N was dramatically accelerated under solvent-free conditions to afford (E)-1,2,4-triazole-substituted alkenes 3 with excellent yields.

Keywords:

• Acceleration
• Baylis–Hillman acetates
• solvent-free conditions
• (E)-1
• 2
• 4-triazole-substituted alkenes

ACKNOWLEDGMENTS

We are grateful to the National Natural Science Foundation of China (Nos. 20476098 and 20676123) for financial support.

Notes

^a 2.0 mmol of Baylis–Hillman acetates, 2.2 mmol of triazole, and 1.1 mmol of K₂CO₃ or 2.2 mmol of Et₃N were used.

^b Isolated yields based on Baylis–Hillman acetates.

^c Complex mixture was obtained.

^d The starting material was recovered.

^e The ratio of 3a and 4a was determined from the ¹H NMR spectrum.

^a 2.0 mmol of Baylis–Hillman acetates, 2.2 mmol of triazole, and 2.2 mmol of Et₃N were used.

^b Isolated yields based on Baylis–Hillman acetates.

^c The addition was very slow in the absence of Et₃N.