Synlett 2010(8): 1231-1234  
DOI: 10.1055/s-0029-1219784
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Indium-Catalyzed N-Formylation of Amines under Solvent-Free Conditions

Joong-Gon Kima, Doo Ok Jang*b
a Biotechnology Division, Hanwha Chemical R&D Center, Daejeon 305-345, South Korea
b Department of Chemistry, Yonsei University, Wonju 220-710, South Korea
Fax: +82(33)7602182; e-Mail: dojang@yonsei.ac.kr;
Further Information

Publication History

Received 8 February 2010
Publication Date:
23 March 2010 (online)

Abstract

We have developed a simple, mild method for N-formylation of a wide variety of amines in the presence of indium metal as a catalyst under solvent-free conditions. This reaction is applicable to the chemoselective N-formylation of amino groups and α-amino acid esters without epimerization.

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Typical procedure for the formylation of amines: A mixture of amine (2 mmol), formic acid (purity = 99%; 226 µL, 6 mmol), and In metal (23 mg, 0.2 mmol) was stirred at 70 ˚C, and the reaction was monitored by TLC. After completion of the reaction, the mixture was diluted with CH2Cl2 and filtered through Celite. The filtrate was washed with saturated NaHCO3 and brine, then dried over anhydrous MgSO4. After filtration and evaporation of the solvent, the residue was purified by column chromatography on silica gel to give the formylated product.