[3+2] Dipolar cycloadditions of an unstabilised azomethine ylide under continuous flow conditions

Autor:	Andrew C. Mansfield, M. Jonathan Fray, Mark Grafton
Rok vydání:	2010
Předmět:	Continuous flow Organic Chemistry Azomethine ylide Methacrylate Biochemistry Medicinal chemistry Cycloaddition Catalysis chemistry.chemical_compound chemistry Drug Discovery Trifluoroacetic acid Ethyl acrylate Organic chemistry Amine gas treating
Zdroj:	Tetrahedron Letters. 51:1026-1029
ISSN:	0040-4039
DOI:	10.1016/j.tetlet.2009.12.071
Popis:	The [3+2] dipolar cycloaddition reactions of the unstabilised azomethine ylide precursor benzyl(methoxymethyl)(trimethylsilylmethyl)amine with 12 electron-deficient alkenes in the presence of catalytic trifluoroacetic acid are examined under continuous flow conditions (20–100 °C, 10–60 min residence time). The more reactive and hazardous alkenes such as ethyl acrylate, N -methylmaleimide and ( E )-2-nitrostyrene afford substituted N -benzylpyrrolidine products in 77–83% yields, whereas less reactive dipolarophiles such as ( E )-crotononitrile and ethyl methacrylate give lower yields (59–63%). Under optimised conditions, the reaction with ethyl acrylate is scaled up to afford ethyl N -benzylpyrrolidine-3-carboxylate (30 g, 87%) in 1 h.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::70e63dff02f0c12d05ebdaf2ff1014df https://doi.org/10.1016/j.tetlet.2009.12.071 Zobrazit plný text záznamu Full Text from ScienceDirect