Cu-catalyzed arylation of the amino group in the indazole ring: regioselective synthesis of pyrazolo-carbazoles

Arylated aminoindazoles were synthesized by copper-catalyzed C–N bond cross-coupling with boronic acids. These were then transformed to pyrazolo-carbazoles by Pd-catalyzed regioselective cross-dehydrogenative coupling.

Tetrahydropyranyl ether (THPE) formation in hydroxyl group protection and conversion to other useful functionalities

This short review highlights the various methods of formation of tetrahydropyranyl ethers (THPEs) as a method for the protection of simple alcohols as well as a diverse range of complex molecules, using a variety of reagents and reaction conditions including their direct conversion to other useful functionalities.

Synthesis and cytotoxic activity of some new 2,6-substituted purines

A seriesof twenty four acyclic unsaturated 2,6-substututed purines 5a-20b were synthesized. These compounds were evaluated for cytotoxic activity against NCI-60 DTP human tumor cell line screen at 10µMconcentration. N₉-[(Z)-4'-chloro-2'-butenyl-1'-yl]-2,6-dichloropurine(5a), N₉-[4'-chloro-2'-butynyl-1'-yl]-2,6-dichloropurine(10a), N₉-[(E)-2',3'-dibromo-4'-chloro-2'-butenyl-1'-yl]-6-methoxypurine(14)and N₉-[4'-chloro-2'-butynyl-1'-yl]-6-(4-methoxyphenyl)-purine(19)exhibited highly potent cytotoxic activity with GI₅₀ values in the 1-5 µM range for most human tumor cell lines. Other compounds exhibited moderate activity.