Aqueous Suzuki Reactions: A Greener Approach to Transition Metal-Mediated Aryl Couplings in the Organic Instructional Laboratory

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 14 Issue 6 (2009) pp 258-260

Aqueous Suzuki Reactions: A Greener Approach to Transition Metal-Mediated Aryl Couplings in the Organic Instructional Laboratory

Devin A. Pantess and Christine V. Rich*

Department of Chemistry, University of Louisville, Louisville, KY 40292; christine.rich@louisville.edu
Received May 11, 2009. Accepted November 8, 2009.

Published online: 31 December 2009

Abstract. A microscale organic laboratory experiment for the synthesis of 4'-phenyl-acetanilide via a Suzuki cross-coupling reaction using student-generated para-bromoacetanilide as substrate is presented. The methodology employs recent advances for the “greening” of the Suzuki reaction by using water as solvent, TBAB (tetra-n-butylammonium bromide) for solvation assistance, and a small amount (1 mol %) of palladium acetate as catalyst. The solid product is easily purified by microcolumn chromatography and characterized by melting point, ¹H, and ¹³C NMR spectroscopy. Pedagogical advantages of this multi-step sequence include: student exposure to contemporary trends in organic synthesis employing transition metal-mediated catalysis, interpretation of intermediate-level NMR spectra, and contextual applications of thin layer and gravity column chromatographic techniques. This experiment also reinforces an emphasis on Green Chemistry and microscale practices in modern organic synthesis.

Key Words: Laboratories and Demonstrations; organic chemistry

(*) Corresponding author. (E-mail: christine.rich@louisville.edu)

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Supporting Materials:

The detailed student experimental handout, instructor’s notes, and ¹H and ¹³C NMR spectra of 4'-phenylacetanilide are available (152 KB)