Nano copper oxide mediated ligand-free C–S cross-coupling and concomitant oxidative aromatization of 4-aryl-3,4-dihydropyrimidin-2(1H)-thione with diaryliodonium salts

Synthesis of Arylthiopyrimidines by Copper‐catalyzed Aerobic Oxidative C–S Cross‐coupling

“…At first, the steric effect of the alkoxy carbonyl group at C5 and alkyl group at C6 was investigated (Scheme ). For the alkoxy carbonyl group, reaction yields decreased as its steric bulk increased‐ an order of t ‐Bu ( 9 ) > i ‐Pr ( 38 ) > Et ( 37 ) > Me ( 36 ). Regarding the substituent at C6, Et and i ‐Pr group afforded 39 and 40 , respectively, in same yield (76%), which are lower than that in the Me group case ( 9 , 85%).…”

Copper-Catalyzed Arylation with Diaryliodonium Salts

“…Karade and co-workers described a method for the arylation of 4-aryl-3,4-dihydropyrimidine-2(1H)-thiones 189 with diaryliodonium salts using CuO nanoparticles as catalyst (Scheme 60). 93 Formation of a mixture of the arylated 2-arylthio-1,4-dihydropyrimidine 190' and aromatized 2-(arylthio)pyrimidine 190 was observed when 1 equivalent of the diaryliodonium triflate was used. With 1.5 equivalents of the hypervalent iodine reagent, however, the aro-…”

Diaryliodonium Salts in Organic Syntheses: A Useful Compound Class for Novel Arylation Strategies

“…dine-2-thiones 20 was also realized by the same research group with diaryliodonium salts and K 2 CO 3 as the base in dimethylformamide, but nano CuO had to be utilized as a catalyst during the transformation.…”