Stereoselective Direct N‐Trifluoropropenylation of Heterocycles with a Hypervalent Iodonium Reagent

The availability and synthesis of fluorinated enamine derivatives such as N-(3,3,3-trifluoropropenyl) heterocycles are challenging, especially through direct functionalization of the heterocyclic scaffold. Herein, a stereoselective N-trifluoropropenylation method based on the use of a bench-stable trifluoropropenyl iodonium salt is described. This reagent enables the straightforward trifluoropropenylation of various N-heterocycles under mild reaction conditions, providing trifluoromethyl enamine type moieties with high stereoselectivity and efficiency

Efficient Copper-Catalyzed Trifluoromethylation of Aromatic and Heteroaromatic Iodides: The Beneficial Anchoring Effect of Borates

Efficient copper - catalyzed trifluoromethylation of aromatic iodides was achieved with TMSCF 3 in the presence of trimethoxyborane. The Lewis acid was used to anchor the in situ generated trifluoromethyl anion and suppress its rapid decomp os i- tion. Broad applicability of the new trifluoromethylating reaction was demonstrated in the functionali zation of different aromatic and heteroaro matic iodides

Understanding and Exploitation of Neighboring Heteroatom Effect for the Mild N-arylation of Heterocycles with Diaryliodonium Salts under Aqueous Conditions: A Theoretical and Experimental Mechanistic Study.

The mechanism of arylation of N-heterocycles with unsymmetric diaryliodonium salts is elucidated. The fast and efficient N-arylation reaction is interpreted in terms of the bifunctionality of the substrate: The consecutive actions of properly oriented Lewis base and Brønsted acid centers in sufficient proximity result in the fast and efficient N-arylation. The mechanistic picture points to a promising synthetic strategy where suitably positioned nucleophilic and acidic centers enable functionalization, and it is tested experimentally

Transition-Metal-Free N-Arylation of Pyrazoles with Diaryliodonium Salts

A new synthetic method was developed for the N-arylation of pyrazoles using diaryliodonium salts. The transformation does not require any transition-metal catalyst and provides the desired N-arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodonium salts was also explored with large number of examples