Synlett 2014; 25(13): 1863-1868
DOI: 10.1055/s-0034-1378274
letter
© Georg Thieme Verlag Stuttgart · New York

Nucleophilic Addition Reactions of Nitriles to Nitrones under Mild Silylation Conditions

Fumihiko Yoshimura*
a  Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan   Fax: +81(11)7064920   Email: fumi@sci.hokudai.ac.jp   Email: ktanino@sci.hokudai.ac.jp
,
Taiki Abe
b  Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
,
Keiji Tanino*
a  Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan   Fax: +81(11)7064920   Email: fumi@sci.hokudai.ac.jp   Email: ktanino@sci.hokudai.ac.jp
› Author Affiliations
Further Information

Publication History

Received: 09 April 2014

Accepted after revision: 07 May 2014

Publication Date:
24 June 2014 (online)


Abstract

In the presence of triethylsilyl trifluoromethanesulfonate and triethylamine, aliphatic nitriles undergo addition reactions with aldonitrones under non-basic, mild conditions, providing O-tri­ethylsilyl ethers of β-N-hydroxyamino nitriles with high yield. The reaction appears to proceed through formation of an N-silyl ketene imine in situ followed by a Mannich-type reaction.

Supporting Information

 
  • References and Notes


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  • 19 General Procedure (Table 1, entry 6): To a mixture of nitrone 10 (0.4 mmol), nitrile 13 (0.4 mmol), and Et3N (0.8 mmol) in DCE (2 mL), was added TESOTf (0.8 mmol) at –30 °C, and the reaction mixture was stirred at this temperature for 30 min. Sat. aq sodium bicarbonate (1 mL) was added to the mixture, and the product was extracted with EtOAc. The combined organic layers were dried over MgSO4 and concentrated under reduced pressure. Purification by flash column chromatography (SiO2; hexane–Et2O, 15:1) afforded O-TES β-hydroxyamino nitrile 14c (0.377 mmol, 94%).