A new general route for the synthesis of novel β-aryl-β-(methylthio)acroleins, a class of stable potential 1,3-dielectrophilic synthons, has been reported. The overall protocol involves treatment of either β-chloroacroleins or their precursor iminium salts (generated in situ from the corresponding active methylene ketones under Vilsmeier–Haack reaction conditions) with S,S-dimethyldithiocarbonates
Base catalyzed reaction of ethyl thioglycolate with β-aryl-β-(methylthio) acroleins: a general method for the synthesis of 2-carbethoxy-5-substituted/4,5-annulated thiophenes in high overall yields
were shown to be stable unlike their counterpart the chloroacroleins and their efficacy as 1,3-dielectrophilic properties have now been examined successfully in this work. They are shown to react with ethyl thioglycolate in the presence of anhydrous potassium carbonate in boiling ethanol to yield the corresponding 5-substituted/4,5-annulated-2-carbethoxy thiophenes in 70–80% overall high yields.
作者:Sarah-Jane Poingdestre、Jonathan D. Goodacre、Andrew S. Weller、Michael C. Willis
DOI:10.1039/c2cc32713a
日期:——
The use of the electron-rich diphosphine ligand, dcpe, allows the efficient and highly linear selective hydroacylative coupling of aldehydes, including aryl examples, with a range of alkynes.