[Hydroxy(tosyloxy)iodo]benzene-mediated regeneration of carbonyl compounds by cleavage of carbon nitrogen double bonds

Abstract

Hydroxy(tosyloxy)iodo]benzene (HTIB, PhI(OH)OTs) is a versatile hypervalent iodine(III) reagent that has numerous applications in organic synthesis [1].

Synthesis of 5-aryl-3-C-glycosyl- and unsymmetrical 3,5-diaryl-1,2,4-triazoles from alkylidene-amidrazones

“…[10][11][12] Construction of ve membered aromatic heterocycles with three heteroatoms in the 1,2,4-(or 1,3,4-) positions is frequently based on oxidative ring closing reactions of N-acyl-hydrazones and analogous compounds (Scheme 2): thus, N-acyl-and Nthioacyl-hydrazones K give the corresponding 1,3,4-oxa-and -thiadiazoles L, respectively. The analogous formation of 1,2,4triazoles is also known, however, this method is almost exclusively used for the synthesis of various condensed 1,2,4-triazoloheterocycles R from cyclic amidrazones Q 13,14 (some literature examples using various oxidants: Br 2 , 15 Pb(OAc) 4 , 16,17 NBS, 18 air (O 2 ), 19 and hypervalent iodine reagents [20][21][22][23] ). Formation of 3,4,5trisubstituted-1,2,4-triazoles from aldehyde tosylhydrazones and Schiff-bases under oxidative conditions (PhIO and NBS) was also reported.…”