Substituted alkyne synthesis under nonbasic conditions: copper carboxylate-mediated, palladium-catalyzed thioalkyne-boronic acid cross-coupling.
[figure: see text] A new methodology for the synthesis of substituted alkynes is described. In the presence of copper(I) thiophene-2-carboxylate (CuTC) or copper (I) 3-methylsalicylate (CuMeSal), the palladium-catalyzed cross-coupling of thioalkyne derivatives with boronic acids affords functionalized alkynes in yields ranging from 39 to 91%. This coupling occurs efficiently under mild, nonbasic conditions with a wide variety of thioalkynes and boronic acids, providing a reaction complementary to the Sonogashira protocol.
Savarin
C
C
Department of Chemistry, Emory University, 1515 Pierce Drive, Atlanta, Georgia 30322, USA.
Srogl
J
J
Liebeskind
L S
LS
D000480:Alkynes / Q000138:chemical synthesis*; D001897:Boronic Acids / Q000737:chemistry*; D002264:Carboxylic Acids; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D012459:Salicylates / Q000737:chemistry; D013329:Structure-Activity Relationship; D013457:Sulfur Compounds / Q000737:chemistry; D013876:Thiophenes / Q000737:chemistry
D000480:Alkynes; D001897:Boronic Acids; D002264:Carboxylic Acids; D012459:Salicylates; D013457:Sulfur Compounds; D013876:Thiophenes; C550746:2-thiophene carboxylic acid; D010165:Palladium; D003300:Copper; C033069:methyl salicylate