77896-80-1Relevant academic research and scientific papers
INTRODUCTION OF SUBSTITUENTS INTO 5-MEMBERED AZA-HETEROAROMATICS
Begtrup, Mikael
, p. 573 - 598 (2007/10/02)
With emphasis on mono- and regio-selectively, methods for introduction of substituents at nitrogen and carbon atoms of 5-membered aza-heteroaromatics have been developed.The methods involve application of activation and of assistant groups for direction and protection.Activation has been achieved by the use of quaternary azolium ions and azol-N-oxides as reactive intermediates.If necessary, the N-oxides were further activated by alkylation or acylation.
1,2,3-Triazoles produced from 5-Substituted N-Methoxytriazolium Salts
Begtrup, Mikael
, p. 2749 - 2756 (2007/10/02)
Five reactions, two of which are new, have been observed when 5-substituted 1-methoxy-2-phenyltriazolium salts react with nucleophiles: (i) addition to C-4 with elimination of methanol to give unsymmetrically 4,5-disubstituted triazoles; (ii) displacement of the 5-substituent followed by secondary reactions to give a symmetrically 4,5-disubstituted triazole, a 5-substituted triazole N-oxide, a 4-substituted triazole, or a disubstituted benzeneazoacetonitrile; (iii) deprotonation of the N-methoxy-group with elimination of formaldehyde; (iv) demethylation; (v) abstraction of an α-proton from a 5-alkyl group followed by nucleophilic addition and elimination of methanol to give an α-substituted 5-alkyltriazole.The reactions are of synthetic potential as a means of introducing one or two substituents in the 1,2,3-triazole system.
