Synthesis of Aminoallenes via Selenium‐π‐Acid‐Catalyzed Cross‐Coupling of N ‐Fluorinated Sulfonimides with Simple Alkynes

A step‐ and redox‐economic route toward aminoallenes from simple alkynes and N‐fluorobenzenesulfonimide (NFSI) was established via selenium‐π‐acid catalysis. This unprecedented method significantly streamlines the assembly of heterosubstituted 1,3‐propadiene motifs and is characterized by a broad functional group tolerance. The facile synthesis of aminoallenes, accomplished by a selenium‐π‐acid‐catalyzed cross‐coupling of an N‐fluorinated sulfonimide with simple, non‐activated alkynes, is reported. Until now, aminoallenes were difficult to be accessed by customary means, inasmuch as pre‐activated and, in part, intricate starting materials were necessary for their synthesis. In sharp contrast, the current study shows that ordinary internal alkynes can serve as simple and readily available precursors for the construction of the aminoallene motif. The operating reaction conditions tolerate numerous functional groups such as esters, nitriles, (silyl)ethers, acetals, and halogen substituents, furnishing the target compounds in up to 86 % yield