N-Heteroaromatic Fluoroalkylation through Ligand Coupling Reaction of Sulfones

Ligand coupling on hypervalent main group elements has emerged as a pivotal methodology for the synthesis of functionalized N-heteroaromatic compounds in recent years due to the avoidance of transition metals and the mildness of the reaction conditions. In this direction, the reaction of N-heteroaryl sulfur(IV) and N-heteroaryl phosphorus(V) compounds has been well studied. However, the ligand coupling of sulfur(VI) is still underdeveloped and the reaction of alkyl N-heteroarylsulfones is still elusive, which does not match the high status of sulfones as the chemical chameleons in organic synthesis. Here we present a ligand coupling-enabled formal SO2 extrusion of fluoroalkyl 2-azaheteroarylsulfones under the promotion of Grignard reagents, which not only enriches the chemistry of sulfones, but also provides a novel and practical synthetic tool towards N-heteroaromatic fluoroalkylation.

Merging Fluorine Incorporation and Functional Group Migration

Fluorine incorporation by concomitant fluoroalkyl radical addition to alkene or alkyne and functional group migration (FGM) represents an ingenious and robust strategy for the synthesis of structurally diverse fluorinated compounds. This account gives an overview of related studies in our group, in which three main reaction modes are discussed: 1) radical fluoroalkylative difunctionalization of unactivated alkenes via intramolecular FGM; 2) alkene difunctionalization by docking-migration process using fluoroalkyl-containing bifunctional reagents; 3) incorporation of fluoroalkyl group into C(sp3 )-H bond via consecutive hydrogen atom transfer (HAT) and FGM. Relying on these methods, a variety of trifluoromethylation and di-/mono-fluoroalkylation reactions along with the migration of cyano, heteroaryl, oximino, formyl, alkynyl, and alkenyl groups have been accomplished under mild conditions.

Modular Approach for Diversity-Oriented Synthesis of β-Fluoroalkylated Arenes via Pd/Norbornene Cooperative Catalysis

Herein, we disclose the first versatile and expeditious modular approach for the rapid diversity-oriented synthesis (DOS) of the difunctionalized β-fluoroalkylated arenes via Pd/norbornene cooperative catalysis. This protocol features an excellent functional group tolerance, as well as a broad ipso termination scope. Moreover, this methodology can be expanded to the late-stage modification of biorelevant molecules. Of particular note, this protocol could also streamline the rapid modular assembly of the 13 and 14-membered fluorinated macrolactones, which was extremely challenging otherwise and the resulted β-fluoroalkylated phenylacetylenes could undergo diverse transformations to provide interesting scaffolds.