Shi, Xinzhe published the artcileReaction Conditions for the Regiodivergent Direct Arylations at C2- or C5-Positions of Oxazoles using Phosphine-Free Palladium Catalysts, Quality Control of 87150-13-8, the main research area is arylated oxazole regioselective preparation; oxazole aryl bromide arylation palladium catalyst.
Two sets of reaction conditions for the regiodivergent C2- or C5- direct arylations of oxazole were reported. In both cases, phosphine-free catalysts and inexpensive bases were employed allowing the access to the arylated oxazoles I [R = H, 4-ClC6H4, 1-naphthyl, etc.; R1 = H, 4-O2NC6H4, 4-pyridyl, etc.] in moderate to high yields. Using Pd(OAc)2/KOAc as catalyst and base, regioselective C5-arylations were observed; whereas, using Pd(acac)2/Cs2CO3 system, the arylation occurred at the C2-position of oxazole. The higher reactivity of C5-H bond of oxazole as compared to the C2-H bond in the presence of Pd(OAc)2/KOAc system was consistent with a concerted metalation deprotonation mechanism; whereas the C2-arylation likely occurred via a simple base deprotonation of the oxazole C2-position. Then, from these C2- or C5-arylated oxazoles, a second palladium-catalyzed direct C-H bond arylation afforded 2,5-diaryloxazoles with two different aryl groups. Also applied these sequential arylations to the straightforward synthesis of 2-arylphenanthro[9,10-d]oxazoles via three C-H bond functionalization steps. The Ru-catalyzed C-H arylation of the aryl unit of 2-aryloxazoles was also described.
Advanced Synthesis & Catalysis published new progress about Aryl bromides Role: RCT (Reactant), RACT (Reactant or Reagent). 87150-13-8 belongs to class nitriles-buliding-blocks, name is 4-(5-Oxazolyl)benzonitrile, and the molecular formula is C10H6N2O, Quality Control of 87150-13-8.
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts