Highly chemoselective Baylis-Hillman and aldol reactions of 2H-thiopyran-4(3H)-one using tertiary amine catalysts in aqueous media.
For the first time, the Baylis-Hillman (BH) reaction of 2H-thiopyran-4(3H)-one is investigated, and surprisingly, the reaction of 2H-thiopyran-4(3H)-one with aldehydes in the presence of different tertiary amines shows excellent chemo- and regioselectivity in water. At room temperature, DBU affords BH adducts, but with DABCO, aldol products were obtained. In the case of DABCO, Et(3)N, or DMAP, domino aldol-rearrangement reactions occurred at 45-50 °C.
Eftekhari-Sis
Bagher
B
Department of Chemistry, Faculty of Science, University of Maragheh, Golshar, P.O. Box. 55181-83111, Maragheh, Iran. eftekharisis@maragheh.ac.ir
Akbari
Ali
A
Harms
Klaus
K