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The first effective and simple method for the direct one-pot transformation of 2-, 3-, and 4-aminopyridines, 2,6-diaminopyridines, and 2-aminoquinoline into the corresponding pyridinyl and quinolinyl trifluoromethanesulfonates and tosylates in solvents was developed. The procedure involves diazotization of the heterocyclic amines with sodium nitrite in mixed hexane-DMSO or hexane-DMF solutions in the presence of trifluoromethanesulfonic acid or p-toluenesulfonic acid. [ABSTRACT FROM AUTHOR]

Convenient access to a variety of 2-arylated pyrazolo[1,5-a]pyridine via pyrazolo[1,5-a]pyridine-2-yl triflate using the Suzuki- Miyaura cross-coupling reaction is described. Fifteen 2-arylpyrazolo[ 1,5-a]pyridine derivatives were synthesized in 52-95% yields. [ABSTRACT FROM AUTHOR]

A series of novel 1'-O-a-methyl isonucleosides were efficiently and stereoselectively synthesized with 1,2,3,5-tetra-Oacetyl-D-ribofuranose as the starting material. The key steps include regioselective and stereoselective deprotection of the 2,4-dichlorobenzyl group at C2, triflation, and substitution with appropriate nucleobases using cesium carbonate as the base. Removal of the residual 2,4-dichlorobenzyl groups and subsequent transformation afforded the title compounds in 30-37% overall yield. The products represent a new type of isonucleosides with 1'-O-substitution. [ABSTRACT FROM AUTHOR]