- Rh(I)-bisphosphine-catalyzed asymmetric, intermolecular hydroheteroarylation of α-substituted acrylate derivatives
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Asymmetric hydroheteroarylation of alkenes represents a convenient entry to elaborated heterocyclic motifs. While chiral acids are known to mediate asymmetric addition of electron-rich heteroarenes to Michael acceptors, very few methods exploit transition metals to catalyze alkylation of heterocycles with olefins via a C-H activation, migratory insertion sequence. Herein, we describe the development of an asymmetric, intermolecular hydroheteroarylation reaction of α-substituted acrylates with benzoxazoles. The reaction provides 2-substitued benzoxazoles in moderate to excellent yields and good to excellent enantioselectivities. Notably, a series of mechanistic studies appears to contradict a pathway involving enantioselective protonation of a Rh(I)-enolate, despite the fact that such a mechanism is invoked almost unanimously in the related addition of aryl boronic acids to methacrylate derivatives. Evidence suggests instead that migratory insertion or beta-hydride elimination is enantiodetermining and that isomerization of a Rh(I)-enolate to a Rh(I)-heterobenzyl species insulates the resultant α-stereocenter from epimerization. A bulky ligand, CTH-(R)-Xylyl-P-Phos, is crucial for reactivity and enantioselectivity, as it likely discourages undesired ligation of benzoxazole substrates or intermediates to on- or off-cycle rhodium complexes and attenuates coordination-promoted product epimerization.
- Filloux, Claire M.,Rovis, Tomislav
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- Synthesis of Highly Functionalized N,N-Diarylamides by an Anodic C,N-Coupling Reaction
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We report an innovative, sustainable and straightforward protocol for the synthesis of N,N-diarylamides equipped with nonprotected hydroxyl groups by using electrosynthesis. The concept allows the application of various substrates furnishing diarylamides with yields up to 57 % within a single and direct electrolytic protocol. The method is thereby easy to conduct in an undivided cell with constant current conditions offering a versatile and short-cut alternative to conventional pathways.
- D?rr, Maurice,Lips, Sebastian,Martínez-Huitle, Carlos Alberto,Schollmeyer, Dieter,Franke, Robert,Waldvogel, Siegfried R.
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- Copper-catalyzed oxidative decarboxylative C-H arylation of benzoxazoles with 2-nitrobenzoic acids
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A copper-catalyzed oxidative decarboxylative coupling of benzoxazoles with 2-nitrobenzoic acids was developed. This methodology favors electron-rich benzoxazoles and electron-deficient benzoic acids and enables the preparation of a variety of arylated benzoxazoles in good yields. The trends in product yields suggest a delicate balance between the decarboxylation and C-H arylation steps.
- Chen, Lijun,Ju, Lin,Bustin, Katelyn A.,Hoover, Jessica M.
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- Method for synthesizing benzoxazole through microwave radiation of benzamide compound in water phase
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The invention discloses a method for synthesizing benzoxazole through microwave radiation of a benzamide compound in a water phase. The benzamide compound is added into the water phase under the microwave condition to be subjected to a cyclization reaction for generating the benzoxazole under the alkali condition, and the method for preparing the benzoxazole is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applied to a large number of functional groups, the yield is high, the number of by-products is small, and the method is easy to operate, safe, low in cost and environmentally friendly. (Please see the specifications for the formula).
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Paragraph 0076
(2019/03/08)
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- 1H-PYRAZOLO[4,3-B]PYRIDINES AS PDE1 INHIBITORS
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The present invention provides 1H-pyrazolo[4,3-b]pyridines of formula (I) as PDE1 inhibitors and their use as a medicament, in particular for the treatment of neurodegenerative disorders and psychiatric disorders.
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Paragraph 0705-0706
(2019/07/10)
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- COMPOUND HAVING ZNF143 INHIBITORY ACTIVITY AND USE THEREOF
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PROBLEM TO BE SOLVED: To provide a compound having a ZNF143 inhibitory activity as well as to provide a ZNF143 inhibitory agent and pharmaceutical composition containing the same. SOLUTION: Provided is a compound represented by formula (I) or a salt thereof as well as a ZNF143 inhibitory agent containing the same and a pharmaceutical composition having the same as an active ingredient. A-B-C-D (I)[A is H, a methyl group, a naphthyl group, a phenyl group or a nitrogen-containing heterocyclic ring; B is as shown below, and C is an amide bond or a heteroaromatic ring containing N and O; D is a substituted/unsubstituted phenyl group or a monocyclic heteroaromatic ring containing N or S; and C and D are both fused heterocyclic ring or the like optionally having a substituent group.]. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0090; 0121; 0122
(2016/10/27)
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- Direct C-H iodination of 1,3-azoles catalysed by CuBr2
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A mild method was developed for the direct C-H iodination of 1,3-azoles catalysed by CuBr2. Compared with the traditional metalation/iodination sequences carried out with nBuLi or TMPLi (TMP = 2,2,6,6-tetramethylpiperidino), a relatively weaker base, LiOtBu, was used in the presence of 1,10-phenanthroline. Five series of 1,3-azoles, including benzoxazole, benzothiozole, N-methyl-benzoimidazole, 5-phenyloxazole and 2-phenyl-1,3,4-oxadiazole were tested and afforded the corresponding iodination products.
- Zhao, Xia,Ding, Fang,Li, Jingyu,Lu, Kui,Lu, Xiaoyu,Wang, Bin,Yu, Peng
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supporting information
p. 511 - 513
(2015/02/19)
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