87150-14-9Relevant academic research and scientific papers
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.).
Nickel-catalyzed decarboxylative acylation of heteroarenes by sp 2 C-H functionalization
Yang, Ke,Zhang, Cheng,Wang, Peng,Zhang, Yan,Ge, Haibo
supporting information, p. 7241 - 7244 (2014/06/23)
Nickel-catalyzed ligand-free decarboxylative cross-coupling of azole derivatives with α-oxoglyoxylic acids has been developed. This work represents the first example of decarboxylative cross-coupling reactions, in a C-H bond functionalization manner, thro
Nickel-catalyzed decarboxylative arylation of heteroarenes through sp2 C-H functionalization
Yang, Ke,Wang, Peng,Zhang, Cheng,Kadi, Adnan A.,Fun, Hoong-Kun,Zhang, Yan,Lu, Hongjian
supporting information, p. 7586 - 7589 (2015/04/22)
The direct decarboxylative arylation of hetereoarenes with benzoic acids through a nickel-catalyzed sp2 C-H functionalization process was developed. This process provides the first examples of decarboxylative cross-coupling reactions with aroma
Copper-mediated C-H/C-H biaryl coupling of benzoic acid derivatives and 1,3-azoles
Nishino, Mayuko,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information, p. 4457 - 4461 (2013/05/22)
Hot couple: A precious-metal-free copper-mediated intermolecular direct biaryl coupling of benzoic acid derivatives and 1,3-azoles has been developed. The key to success is the installation of an amide-based bidentate coordinating group, which is easily removed and transformed into the parent ester groups after the coupling reaction. Kinetic studies indicate that the rate-limiting step is the aromatic C-H bond cleavage of benzoic acid derivatives. Copyright
Copper-mediated dehydrogenative biaryl coupling of naphthylamines and 1,3-azoles
Odani, Riko,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
, p. 11045 - 11052 (2013/11/19)
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
One-pot sequential direct C-H bond arylation of azoles catalyzed by [Pd(phen)2](PF6)2: Synthetic methods for triarylated azoles
Shibahara, Fumitoshi,Yamauchi, Takayuki,Yamaguchi, Eiji,Murai, Toshiaki
, p. 8815 - 8820,6 (2020/09/15)
Synthetic methods for triarylated azoles containing three different aryl groups via one-pot sequential multiple C-H bond arylations are described. The one-pot sequential diarylation of C5-monoarylated azoles was achieved by the simple sequential addition of two different aryl iodides with a [Pd(phen) 2]PF6 catalytic system. The one-pot triarylation of N-methylimidazole was achieved by the combination of a previously reported Pd(OAc)2-P(2-furyl)3 system and the present [Pd(phen) 2]PF6 system. In this case, portionwise addition of aryl halide, base and the catalyst in the final step significantly improved the overall yield of the desired triarylated product. These protocols led to triarylated azoles without a loss of efficiency compared to the corresponding previously reported stepwise syntheses via direct C-H bond arylation.
Aminooxazole Inhibitors of Cyclin Dependent Kinases
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Page/Page column 27, (2012/12/13)
Oxazole derivatives are described. The inventive compounds are useful as kinase inhibitors, and may be used in the treatment of cancer, such as prostate cancer, lung cancer, breast cancer, colon cancer, leukemia, CNS cancer, melanoma, ovarian cancer, and
Copper-mediated intermolecular direct biaryl coupling
Kitahara, Masanori,Umeda, Nobuyoshi,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information; body text, p. 2160 - 2162 (2011/04/23)
Copper-mediated intermolecular direct biaryl coupling of arylazines and azoles via dual C-H bond cleavage proceeds even without palladium catalysts. The reaction system shows the high potential of copper salts in direct C-H arylation chemistry and provides a new approach to biaryl motifs, which are ubiquitous in pharmaceuticals and functional materials.
Cobalt-catalyzed addition of azoles to alkynes
Ding, Zhenhua,Yoshikai, Naohiko
supporting information; experimental part, p. 4180 - 4183 (2010/11/19)
A ternary catalytic system consisting of a cobalt salt, a diphosphine ligand, and a Grignard reagent promotes syn-addition of an azole C(2)-H bond across an unactivated internal alkyne with high chemo-, regio-, and stereoselectivities under mild conditions. Mechanistic experiments suggest that the reaction involves oxidative addition of the oxazolyl C-H bond to the cobalt center, alkyne insertion into the Co-H bond, and reductive elimination of the resulting diorganocobalt species.
Highly regioselective palladium-catalyzed direct arylation of oxazole at C-2 or C-5 with aryl bromides, chlorides, and triflates
Strotman, Neil A.,Chobanian, Harry R.,Guo, Yan,He, Jiafang,Wilson, Jonathan E.
supporting information; experimental part, p. 3578 - 3581 (2010/11/04)
Complementary palladium-catalyzed methods for direct arylation of oxazole with high regioselectivity (>100:1) at both C-5 and C-2 have been developed for a wide range of aryl and heteroaryl bromides, chlorides, iodides, and triflates. C-5 arylation is pre
