B₂O₃/Al₂O₃ as an Efficient and Recyclable Catalyst for the Synthesis of β-Amino Alcohols under Solvent-Free Conditions

Abstract

A convenient and efficient procedure for the solvent-free synthesis of β-amino alcohols has been achieved via B₂O₃/Al₂O₃-promoted highly regioselective ring opening of epoxides with aromatic amines in good to excellent yields at room temperature. Additionally, the catalyst can be recycled without affecting the catalytic property.

Keywords:

• β-Amino alcohols
• Anilines
• B₂O₃/Al₂O₃, Epoxides, Solvent-free conditions

ACKNOWLEDGMENT

We are grateful to the National Natural Science Foundation of China (Nos. 20476098 and 20504023), and Natural Science Foundation of Zhengjiang Province (Nos. Y405015 and Y405113), and Science and Technology Program of Zhengjiang Province (No. 2003C31026) for financial support.

Notes

^a Isolated yield.

^b Regioisomers were determined using ¹H NMR.

^c 0.01 g of B₂O₃/Al₂O₃ was used as a catalyst.

^d 0.05 g of B₂O₃/Al₂O₃ was used as a catalyst.

^e In the absence of catalyst.

^f 0.03 g of Al₂O₃ was used as a catalyst.

^a Isolated yields.

^b Regioisomers were determined using ¹H NMR.

^c At 60 °C.

^a Isolated yields.