Ionic Thiourea Organocatalysis of the Morita–Baylis–Hillman Reaction
2016; CSIRO Publishing; Volume: 69; Issue: 7 Linguagem: Inglês
10.1071/ch15596
ISSN1445-0038
AutoresTrevor A. McGrath, Katherine N. Robertson, Jason D. Masuda, Jason A. C. Clyburne, Robert D. Singer,
Tópico(s)Carbohydrate Chemistry and Synthesis
ResumoAn ionic thiourea based organocatalyst has been shown to promote a 1,4-diazabicyclo[2.2.2]octane, (DABCO) catalysed Morita-Baylis-Hillman reaction between benzaldehyde and cyclohex-2-en-1-one. The ionic thiourea catalyst was easily prepared from a pyrrolidinium salt containing an arylamine moiety and 3,5-di(trifluoromethyl)phenylisothiocyanate. X-ray crystallographic analysis of the ionic thiourea catalyst shows an acetone molecule doubly hydrogen bonded to the Lewis acidic thiourea N-H protons. Entrainment of the ionic thiourea co-catalyst in the ionic liquid N-butyl-N-methylpyrrolidinium bistriflimide, [BMPyr][N(Tf)2], facilitates catalyst recycling and affords very good yields with reaction times reduced through use of microwave heating.
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