Trifluoromethylselenylative Difunctionalization of Arynes with Me 4 N SeCF 3 †

Comprehensive Summary A general protocol for the trifluoromethylselenylative difunctionalization of aryne with the nucleophilic Me 4 NSeCF 3 reagent is described. The NiCp 2 ‐catalyzed cross‐couplings of o ‐silylaryl triflates, Me 4 NSeCF 3 , and CsF with H 2 O/CH 3 CN, D 2 O/CD 3 CN, and n ‐C 4 F 9 I or C 6 F 13 Br or CCl 4 afforded the hydrotrifluoromethylselenylated products, deuterotrifluoromethylselenylated products, and halotrifluoromethylselenylated products, respectively, while the metal‐free reaction of o ‐silylaryl triflates and Me 4 NSeCF 3 with NFSI provided the bis(trifluoromethylselenylated) products. These reactions allowed for the facile synthesis of diverse difunctionalized SeCF 3 products in good yields, which are unprecedented and difficult to synthesize by other methods. In the Ni‐catalyzed reactions, the key aryne intermediate is generated from o ‐silylaryl triflate in the presence of fluoride ion, coordinates with the nickel catalyst, undergoes ligand exchange with the – SeCF 3 anion, and is inserted into the carbon‐carbon triple bond to form an o ‐trifluoromethylselenylaryl‐nickel complex, which is then protonated with H 2 O/CH 3 CN to yield the hydrotrifluoromethylselenylated product, deuterated with D 2 O/CD 3 CN to produce the deuterotrifluoromethylselenylated product, or halogenated with n ‐C 4 F 9 I, C 6 F 13 Br or CCl 4 to afford the halotrifluoromethylselenylated product. In the metal‐free reaction, the – SeCF 3 anion is first oxidized with NFSI to yield •SeCF 3 radical and fluoride ion, which activates o ‐silylaryl triflate in situ to form the aryne species, followed by radical addition with •SeCF 3 and subsequent trapping by another •SeCF 3 radical to produce the bis(trifluoromethylselenylated) product. The moisture‐sensitive Me 4 NSeCF 3 salt was successfully tolerated in the reactions with H 2 O or D 2 O. This work further demonstrated the rich chemistry of Me 4 NSeCF 3 and the power of aryne‐based functionalization as a linchpin step in the production of multi‐substituted SeCF 3 ‐arenes.