Triflimide-Promoted Nucleophilic C-Arylation of Halopurines to Access N7-Substituted Purine Biaryls.

Functionalized nucleobases are utilized in a wide range of fields; therefore, the development of new synthesis methods is essential for their continued application. With respect to the C6-arylation of halopurines, which possess a substituent at the N7-position, only a small number of successful cases have been reported, which is predominately a result of large steric hinderance effects. Herein, we report efficient and metal-free C6-arylations and SNAr reactions of N7-substituted chloropurines in aromatic and heteroatom nucleophiles promoted by triflimide (Tf2NH) in fluoroalcohol.

Nucleophilic Arylation of Halopurines Facilitated by Brønsted Acid in Fluoroalcohol.

Various aryl-substituted purine derivatives were synthesized through the direct arylation of halopurines with aromatic compounds, facilitated by the combination of triflic acid and fluoroalcohol. This metal-free method is complementary to conventional coupling reactions using metal catalysts and reagents for the syntheses of aryl-substituted purine analogues.