1,4-Michael additions of cyclic-β-ketoesters catalyzed by DNA in aqueous media
摘要:
In this work, we describe the 1,4-Michael addition of the 1,3-dicarbonyl compounds to activated ethylenes under st-DNA catalysis in water. The reaction of the beta-ketoester 4 with nitroolefins and conjugated carbonyls proceeds quite well, whereas other less activated ethylenes exhibit low or null reactivity. The catalyst can be recovered and reused for several catalytic cycles without significantly diminishing its efficiency. These reactions are similarly catalyzed by GMP, methyl-adenine and ethyl guanine, which suggests that the catalytic activity of st-DNA could be associated to the basic nature of their nucleotides' integrants. (C) 2013 Elsevier B.V. All rights reserved.