Cyanotriflation gives versatile acrylonitriles

Chemists in Germany have added a new dimension to preparing acrylonitriles with the first method for adding both a cyano group and a triflate group to an alkyne (J. Am. Chem. Soc. 2016, DOI: 10.1021/jacs.6b00869). Xi Wang and Armido Studer of the University of Münster took advantage of a known aryl(cyano)iodonium triflate reagent that other groups have used to transfer the cyano group or the triflate group. But until now, no one had devised a reaction system to add both groups to another molecule at once, in this case a range of alkynes and diynes. The Münster team’s syn addition proceeds with regio- and stereochemical control at up to gram scale via a radical mechanism mediated by an iron phenanthroline catalyst, leading to a host of triflate-modified acrylonitriles. The researchers found that the triflate provides a handle for further functionalizing the acrylonitriles via palladium-catalyzed cross-coupling reactions (example shown) to make even more complex molecules for pharmaceutical and materials applications.