Remarkably Facile Heck Reactions in Aqueous Two-Phase System Catalyzed by Reusable Pd/C Under Ligand-Free Conditions

Abstract

A fast and convenient Heck reaction was achieved catalyzed by Pd/C in aqueous two-phase system. The aqueous two-phase system has been shown to be a highly active solvent for Heck reactions of aryl halides even in the absence of organic ligands.

GRAPHICAL ABSTRACT

Keywords:

• Aqueous two-phase system
• Heck reaction
• Pd/C
• trans-cinnamate

ACKNOWLEDGMENTS

This work was supported by the Natural Science Foundation of Zhejiang Province, China (Project Y407240), and the Key Science Foundation of Lishui University (Project KY07002).

Notes

^a Reaction condition: 3 mmol PhI, 3.3 mmol methyl acrylate, 3 mol% Pd/C, 8 mmol base (or phase separation salts), and solvent (10 mL), reflux at 80 °C for corresponding time by GC or TLC.

^b Isolated yield.

^c Added CTAB.

^a Reaction condition: 3 mmol PhI, 3.3 mmol methyl acrylate, 8 mmol base, 3 mol% Pd/C, ethanol 6 ml, and water 4 ml, reflux at 80 °C for corresponding time by GC.

^b Isolated yield.

^a Reaction condition: 3 mmol ArX, 3.3 mmol olefin, 8 mmol K₂HPO₄, and 3 mol % Pd/C, aqueous two-phase system (10 mL) reflux at 80 °C for corresponding time by GC or TLC.

^b MA: CH₂ = CHCO₂CH₃, BA: CH₂ = CHCO₂(Bu-n), PTEA: CH₂ = CHCO₂CH₂CH₂SPh.

^c Isolated yield.

^d Exit about 1.4–2.0% double-substituted product from the GC/MS.

^a In entry 2, 1.5 mol% Pd/C was used.