An Acidity Scale of Triazolium-Based NHC Precursors in DMSO was written by Li, Zhen;Li, Xin;Cheng, Jin-Pei. And the article was included in Journal of Organic Chemistry in 2017.Electric Literature of C17H24BF4N3O The following contents are mentioned in the article:
An acidity scale of triazolium-based N-heterocyclic carbene precursors was established by measuring 25 compounds’ (10a-15b) equilibrium acidities in DMSO solution using overlapping indicator method. The pKa values ranged from 12.08 to 15.5, responding not only to the N-aryl motif, but also to the core structure. Excellent correlation was observed between the pKa values and the Hammett substituent constants (σp). This study involved multiple reactions and reactants, such as (S)-5-Isopropyl-2-mesityl-6,8-dihydro-5H-[1,2,4]triazolo[3,4-c][1,4]oxazin-2-ium tetrafluoroborate (cas: 1631733-83-9Electric Literature of C17H24BF4N3O).
(S)-5-Isopropyl-2-mesityl-6,8-dihydro-5H-[1,2,4]triazolo[3,4-c][1,4]oxazin-2-ium tetrafluoroborate (cas: 1631733-83-9) belongs to triazole derivatives. Triazoles consist of a five-membered ring containing three nitrogen atoms and are biologically active, especially as antifungal, antimicrobial and enzyme inhibitors. 1,2,3-Triazoles are usually prepared following (3+2) cycloaddition protocols. A common technique for unsubstituted triazoles is the Huisgen azide-alkyne 1,3-dipolar cycloaddition: a azide and an alkyne react at high temperature to form a ring. However, the Huisgen strategy produces a mixture of isomers (typically 1,4- and 1,5-disubstituted) when used to produce substituted triazoles.Electric Literature of C17H24BF4N3O
Referemce:
1,2,3-Triazole – Wikipedia,
Triazoles – an overview | ScienceDirect Topics