Synlett 2009(6): 937-940  
DOI: 10.1055/s-0028-1088194
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Propargylamines by a Copper-Catalyzed Tandem Anti-Markovnikov Hydroamination and Alkyne Addition

Lei Zhoua,b, D. Scott Bohlea, Huan-Feng Jiang*b, Chao-Jun Li*a
a Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 2K6, Canada
Fax: +1(514)3983797; e-Mail: cj.li@mcgill.ca;
b College of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. of China
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Publikationsverlauf

Received 20 November 2008
Publikationsdatum:
16. März 2009 (online)

Abstract

A highly efficient tandem anti-Markovnikov hydroamination and alkyne addition reaction catalyzed by a Cu(I) or Cu(II) catalyst was developed. Various propargylamines were obtained in moderate to good yields. This tandem process provides a novel and simple approach to propargylamine derivatives from alkynes and amines.

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Representative Experimental Procedure Copper(I) bromide (3.6 mg, 0.025 mmol, 5 mol%) was suspended in toluene (2 mL) in a 10 mL Schlenk tube under nitrogen. Then, diallylamine (49 mg, 0.5 mmol) and phenylacetylene (204 mg, 2 mmol) were added. The resulting solution was stirred at 100 ˚C for 24 h. After cooling to r.t., the resulting mixture was filtered through a short path of SiO2 in a pipette eluting with EtOAc. The volatiles were removed in vacuo, and the residue was purified by column chromatography (SiO2, hexane-EtOAc, 10:1) to give 3a (111.3 mg, 74%) as a pale yellow oil. ¹H NMR (400 MHz, CDCl3): δ = 7.42-7.39 (m, 2 H), 7.31-7.23 (m, 8 H), 5.88-5.79 (m, 2 H), 5.23 (d, J = 17.2 Hz, 2 H), 5.13 (d, J = 10.0 Hz, 2 H), 3.97 (t, J = 7.6 Hz, 1 H), 3.41(dt, J = 14.0, 2.4 Hz, 2 H), 3.11-2.97 (m, 4 H). ¹³C NMR (75 MHz, CDCl3): δ = 139.0, 136.6, 131.8, 129.7, 128.4, 128.3, 128.1, 126.5, 123.6, 117.5, 87.7, 86.2, 55.4, 54.3, 40.6. MS (70 eV): m/z (%) = 301 [M+], 274, 242, 215, 210(100), 191, 168, 154, 128, 115, 91. HRMS (EI): m/z calcd for C22H23N [M+]: 301.1831; found: 301.1814.
The experiments in Table  [²] were carried out analogously. All products were purified by column chromatography and characterized by NMR spectroscopy and standard/high-resolution mass spectrometry.