[Structure: see text] An efficient and regioselective procedure for the synthesis of 1,2,3-triazoles via a [3+2] cycloaddition of polymer-bound vinyl sulfone and sodium azide is described. Microwave irradiation provided significant rate enhancement in all steps of the three-step protocol. A representative set of 23 compounds was prepared.

The reaction of 5-benzenesulfonyl-3,4-dihydro-1 H-pyridin-2-one derivatives with azides or isocyanides provided two new classes of compounds, triazolo[4,5-b]pyridin-5-ones 3 or pyrrolo[3,4-b]pyridin-2-ones 4, respectively, in good yields and regioselectivity. A representative set of 20 compound 3 and 12 compound 4 was prepared.

An efficient preparation of a new recyclable polymer-supported oxidizing agent based on Nphenylsulfonyloxaziridine has been developed. This new polymer-supported oxidant was shown to effect a clean and selective conversion of a range of sulfides, selenides, amines, phosphines and enolates to the corresponding sulfoxides, selenoxides, N-oxides, phosphine oxides and a-hydroxy carbonyl compounds. It also enabled tetrahydrobenzimidazoles to be oxidatively rearranged to spiro-fused 5-imidazolones. Recycling of the polymer-supported oxidant is possible with minimal loss of activity after several reoxidations.

No abstract

Fused pyridine derivatives R 0450 [3 + 2] Cycloaddition Reactions in the Synthesis of Triazolo[4,5-b]pyridin-5-ones and Pyrrolo[3,4-b]pyridin-2-ones. -The cycloaddition reaction of pyridine-2-ones (I) with azides or isocyanides provides a representative set of 20 compounds of triazolopyridinones and 12 compounds of pyrrolopyridinone, respectively, in good yields and regioselectivities. -(GAO, Y.; LAM*, Y.; J. Comb. Chem. 10 (2008) 2, 327-332; Dep. Chem., Natl. Univ. Singapore, Singapore 117543, Singapore; Eng.) -Bartels 32-153