159140-82-6

Upstream product

• 352-33-0 1-Chloro-4-fluorobenzene 
• 128101-19-9 5-(4-fluorophenyl)-1,3-oxazole 
• 288-42-6 oxazol 
• 460-00-4 1-Bromo-4-fluorobenzene 

Relevant academic research and scientific papers

Orientation effects on C2(5)-C2?(5?) linked bioxazole isomers synthesized via regioselective and sequential C[sbnd]H arylation

Bis(4-fluorophenyl) substituted oxazole (2,5-Oxz) and C2(5)-C2?(5?) linked bioxazole isomers (C2-C2?_BOxz, C2-C5?_BOxz and C5-C5?_BOxz) were concisely synthesized via palladium-catalyzed regioselective and sequential C[sbnd]H arylation in 1–3 reaction steps along with 20%–83% of total yields from oxazole and 4-bromofluorobenzene. The linking orientation plays a key role in the packing geometry and photophysical properties of C2-C2'_BOxz, C2-C5'_BOxz and C5-C5'_BOxz. These bioxazole isomers in solid state showed significant differences in photoluminescence quantum yields (PLQY) (0.33, 0.25 and 0.04, respectively), delayed fluorescence properties and powder X-ray diffraction (PXRD) patterns, suggesting the divergence in intermolecular interactions. The theoretically calculated gradient isosurfaces and complexation energies indicate the existence of intense π-π interactions between molecular layers, which are in good agreement with the variation trend of optical properties.

Reaction Conditions for the Regiodivergent Direct Arylations at C2- or C5-Positions of Oxazoles using Phosphine-Free Palladium Catalysts

Two sets of reaction conditions for the regiodivergent C2- or C5- direct arylations of oxazole are reported. In both cases, phosphine-free catalysts and inexpensive bases were employed allowing the access to the arylated oxazoles 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 is consistent with a concerted metalation deprotonation mechanism; whereas the C2-arylation likely occurs 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 affords 2,5-diaryloxazoles with two different aryl groups. We 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 is also described. (Figure presented.).

Iodine catalysed intramolecular C(sp3)-H functionalization: synthesis of 2,5-disubstituted oxazoles from N-arylethylamides

Iodine catalyzed synthesis of 2,5-disubstituted oxazoles from N-arylethylamides through intramolecular C(sp3)-H functionalization under metal-free conditions is described. The method is tolerable to a wide range of substrates having a variety of functional groups with moderate to good yields of the products.

Direct C-H bond arylation of (benzo)oxazoles with aryl chlorides catalyzed by N-heterocyclic carbene-palladium(II)-1-methylimidazole complex

The direct C-H bond arylation of (benzo)oxazoles with aryl chlorides was achieved catalyzed by a well-defined NHC-Pd(II)-Im complex. Under the optimal conditions, various aryl chlorides were successfully applied as the arylating reagents to achieve the 2-aryl (benzo)oxazoles in acceptable to high yields, providing a convenient and alternative method for the direct C-H bond arylation of (benzo)oxazoles and enriching the chemistry of the NHC-Pd(II) complex in organic synthesis.