Ultrafast and efficient aza- and thiol-Michael reactions on a polyester scaffold with internal electron deficient triple bonds


Günay U. S. , Cetin M., Daglar O., Hızal G. , Tunca Ü. , Durmaz H.

POLYMER CHEMISTRY, vol.9, no.22, pp.3037-3054, 2018 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 22
  • Publication Date: 2018
  • Doi Number: 10.1039/c8py00485d
  • Title of Journal : POLYMER CHEMISTRY
  • Page Numbers: pp.3037-3054

Abstract

A polyester scaffold possessing electron deficient triple bonds in the main chain was prepared and utilized as a precursor for aza- and thiol-Michael addition reactions. A variety of primary and secondary amines as well as thiol compounds were utilized in the reactions. Very high efficiencies were found for all Michael addition reactions in a reasonably short time (2 min). While aza-Michael addition reactions do not require any catalysts, thiol-Michael addition reactions could be performed in the presence of a catalyst. After a detailed catalyst search, 1,4- diazabicyclo[2.2.2]octane (DABCO) was found to be the most efficient catalyst for thiol-Michael addition reactions. It is also observed that when amidine and guanidine bases were utilized for thiol-Michael addition reactions, a second thiol addition appreciably occurred on the remaining double bonds. Besides, for the first time, one-pot and one-step heterofunctionalization on the polyester was performed either solely by aza-Michael addition reactions employing three or four different secondary amines, or by a combination of aza- and thiol-Michael addition reactions.