C-H arylation of pyridines: high regioselectivity as a consequence of the electronic character of C-H bonds and heteroarene ring

C-H bonds as ubiquitous functionality: preparation of multiple regioisomers of arylated 1,2,4-triazoles via C-H arylation

We describe a general approach for the synthesis of complex aryl 1,2,4-triazoles. The electronic character of the C-H bonds and the triazole ring allows for the regioselective C-H arylation of 1-alkyl- and 4-alkyltriazoles under catalytic conditions. We have also developed the SEM and THP switch as well as trans-N-alkylation, which enable sequential arylation of the triazole ring to prepare 3,5-diaryltriazoles. This new strategy provides rapid access to a variety of arylated 1,2,4-triazoles and well complements existing cyclization methods.

Selective syntheses of no-carrier-added 2- and 3-[18F]fluorohalopyridines through the radiofluorination of halopyridinyl(4'-methoxyphenyl)iodonium tosylates

No-carrier-added 2- and 3-[(18)F]fluorohalopyridines were readily synthesized as potentially useful labeling synthons for prospective PET radiotracers through the selective radiofluorination of halopyridinyl(4'-methoxyphenyl)iodonium tosylates, themselves conveniently prepared in a single pot from iodohalopyridines.

Catalytic arylation of a C-H bond in pyridine and related six-membered N-heteroarenes using organozinc reagents

Despite significant advances in the catalytic direct arylation of heteroarenes, the application of this reaction to pyridines has been met with limited success. An oxidative nucleophilic arylation strategy has been developed to overcome this problem. Pyridine, pyrazine, quinolone, and related electron-deficient N-heteroarenes can be arylated at the most electrophilic site using the developed nickel-catalyzed reaction. This protocol serves as a complementary method to catalytic direct arylation reactions.