1006-68-4Relevant articles and documents
Copper-mediated dehydrogenative biaryl coupling of naphthylamines and 1,3-azoles
Odani, Riko,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
, p. 11045 - 11052 (2013)
A copper-mediated dehydrogenative biaryl cross-coupling of naphthylamines and 1,3-azoles has been developed. The key to its success is the introduction of N,N-bidentate coordination system based on the picolinamide directing group. The reaction proceeds s
Solution-phase parallel oxazole synthesis with TosMIC
Kulkarni, Bheemashankar A.,Ganesan
, p. 5637 - 5638 (1999)
A quaternary ammonium hydroxide ion exchange resin catalyzes the reaction of p-tolylsulfonylmethyl isocyanide (TosMIC) with aromatic aldehydes to give 5-aryloxazoles. The base and the p-tolylsulfinic acid byproduct are removed by simple filtration, result
CONVERSION OF TRIAZOLIDES INTO OXAZOLES BY FLASH-VACUUM PYROLYSIS.
Maquestiau, A.,Puk, E.,Flammang, R.
, p. 4023 - 4024 (1986)
Flash-vacuum pyrolysis of azolides of 1,2,4-triazole affords 5-monosubstituted oxazoles.
Synthesis and reactivities of 1-(isocyanomethyloxy)benzotriazole as a new source of isocyanomethyl synthon
Sasaki, Hideaki
, p. 1369 - 1371 (1997)
The title compound, 1-(isocyanomethyloxy)benzotriazole (6) as a new source of isocyanomethyl synthon, was synthesized in 65% yield by the dehydration of 1-(formamidomethyloxy)benzotriazole with phosphorus oxychloride in the presence of triethylamine. Unde
Tandem cycloaddition-decarboxylation of α-keto acid and isocyanide under oxidant-free conditions towards monosubstituted oxazoles
Zhang, Ling-Juan,Xu, Mei-Chen,Liu, Jie,Zhang, Xian-Ming
, p. 73450 - 73453 (2016)
An efficient method, tandem [3 + 2] cycloaddition-decarboxylation of α-keto acid and isocyanide promoted by copper salt, has been developed. Under oxidant-free conditions, a series monosubstituted oxazoles have been constructed. Different from the traditional application of α-oxo acids as acyl surrogates, the elegant approach herein ingeniously avoids consuming excess oxidants.
Oxazole synthesis with minimal purification: Synthesis and application of a ROMPgel tosmic reagent
Barrett, Anthony G. M.,Cramp, Susan M.,Hennessy, Alan J.,Procopiou, Panayiotis A.,Roberts, Richard S.
, p. 271 - 273 (2001)
equations presented The synthesis of ring opening metathesis, polymer-supported Tosmic reagent 1 is described. This reagent was utilized in the conversion of aldehydes to oxazoles in good yields and purities.
Improvement of the Van Leusen reaction in the presence of β-cyclodextrin: A green and efficient synthesis of oxazoles in water
Rahimzadeh, Golnaz,Kianmehr, Ebrahim,Mahdavi, Mohammad
, p. 923 - 926 (2017)
An efficient approach for the synthesis of oxazoles through the Van Leusen reaction in the presence of β-cyclodextrin is described. In aqueous medium using β-cyclodextrin as a supramolecular catalyst, tosylmethyl isocyanide was deprotonated by triethylami
Cobalt-catalyzed arylation of azole heteroarenes via direct C-H bond functionalization
Sezen, Bengue,Sames, Dalibor
, p. 3607 - 3610 (2003)
(Equation presented) We herein report a new cobalt-catalyzed method for arylation of azole heteroarenes, including thiazole, oxazole, imidazole, benzothiazole, benzoxazole, and benzimidazole. The direct arylation of thiazole and oxazole was achieved both with iodo- and bromoarenes as the aryl donors in the presence of cobalt catalyst [Co(OAc)2/IMes] and cesium carbonate, while imidazole required the use of zinc oxide as the base. A complete reversal of arylation from C-5 to C-2 was accomplished using the bimetallic Co/Cu/IMes system. A direct comparison of the new cobalt method and the previously developed palladium protocol revealed significant differences, in terms of both chemical yield and selectivity.
An efficient two-step synthesis of 2,5-disubstituted oxazole derivatives involving cu-promoted carbon-carbon single bond formation
Maiti, Jyotirmay,Biswas, Suman,Das, Ranjan
, p. 1519 - 1522 (2016)
Environment sensitive fluorescence probe to detect various organelles is emerging as an excellent tool to attract the attention of a large number of researchers around the globe. The recent developments have shown that oxazole dyes are very competent and can exhibit a useful fluorescence property in this direction. An efficient synthetic procedure towards 2,5-diaryl substituted oxazole derivatives have been reported. It is a two-step technique involving classical van Leusen protocol followed by copper-mediated coupling with aryl halides to introduce the required carbon-carbon single bond. The aryl groups are chosen in such a way so that the aryl functionalities at 2- and 5-positions of oxazole can act as acceptor and donor moiety respectively. Thus, in turn, the extended conjugation from donor moiety to acceptor moiety via the oxazole ring is set up therein. The oxazole derivatives were characterized by various spectroscopic measurements like NMR, IR and MS.
Oxazole Synthesis by Sequential Asmic-Ester Condensations and Sulfanyl-Lithium Exchange-Trapping
Mueller, Louis G.,Chao, Allen,Alwedi, Embarek,Natrajan, Maanasa,Fleming, Fraser F.
, p. 1500 - 1503 (2021/03/08)
Oxazoles are rapidly assembled through a sequential deprotonation-condensation of Asmic, anisylsulfanylmethylisocyanide, with esters followed by sulfanyl-lithium exchange-trapping. Deprotonating Asmic affords a metalated isocyanide that efficiently traps esters to afford oxazoles bearing a versatile C-4 anisylsulfanyl substituent. Interchange of the anisylsulfanyl substituent is readily achieved through a first-in-class sulfur-lithium exchange-electrophilic trapping sequence whose versatility is illustrated in the three-step synthesis of the bioactive natural product streptochlorin.
Reaction Conditions for the Regiodivergent Direct Arylations at C2- or C5-Positions of Oxazoles using Phosphine-Free Palladium Catalysts
Shi, Xinzhe,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 4748 - 4760 (2019/09/12)
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.).