CuI/I₂‐Mediated Intramolecular Oxidative Cyclization Reaction of N‐(2‐pyridyl)amidines by the Direct Double C−H Functionalization of a C(sp³)−H Bond

Abstract

Af acile approacht oarare class of 3,3-disubstituted 2-iminoimidazo[1,2-a]-pyridines bearing ah ydroxyl group at the 3p ositioni ng ood to excellenty ields from N-(2-pyridyl)amidines substrates in the presence of CuI/I 2 /KI/KOtBu is described.A ccording to the investigation, the use of aC u catalyst and the presence of sulfonyl groups in the substrates hasaremarkable influence on the successo ft he oxi-dative cyclization reaction. Moreover,t he oxygen source of the hydroxyl group may be from the incorporation of water in the reaction system or KOtBu. The successful implementation of the reactionf urther indicates that amidines have abundant reactivity under variousr eactionc onditions. The methodology is operationally simple and has ab road substrate scope.Scheme1.Previouswork on the oxidative cyclization of N-(2-pyridyl)amidinesa nd this work.[a] Prof.

Research on extraction of Cr(III) by D2EHPA/n‐octanol/sulphonated kerosene

“…Cr(VI) is highly toxic to humans, easy to accumulate, damaging to cells, skin, and mucosa, and carcinogenic. [13][14][15] China stipulates in the comprehensive wastewater discharge standard that the maximum allowable discharge concentration of total chromium is 1.5 mg/L and the maximum allowable discharge concentration of Cr(VI) is 0.5 mg/L. [16] It is noted that China is seriously short of chromium resources and has a large demand for chromium.…”