6307-13-7Relevant academic research and scientific papers
Synthesis and thermally induced structural transformation of phthalimide and nitrile-functionalized benzoxazine: toward smart ortho-benzoxazine chemistry for low flammability thermosets
Zhang, Kan,Liu, Yuqi,Han, Lu,Wang, Jinyun,Ishida, Hatsuo
, p. 1526 - 1535 (2019)
A novel ortho-phthalimide-functionalized benzoxazine monomer containing an ortho-nitrile group has been synthesized in order to further systematically evaluate the thermally induced structural transformation from benzoxazine resin to cross-linked polybenzoxazole. The chemical structure of the synthesized monomer has been confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Also supporting the detailed structure is 1H-13C heteronuclear multiple quantum coherence (HMQC), which identifies the local proton-carbon proximities. The polymerization behaviors, including the ring-opening polymerization of the oxazine rings and the cyclotrimerization of the nitrile functionalities, are studied by differential scanning calorimetry (DSC) and in situ FT-IR. In addition, the subsequent benzoxazole formation after polymerization has also been analyzed using thermogravimetric analysis (TGA) and magic-angle spinning (MAS) solid-state 13C NMR. The resulting cross-linked polybenzoxazole derived from the benzoxazine monomer exhibits exceptionally high thermal stability and low flammability, with an extremely high Td5 temperature (550 °C), a high char yield value (70%) and an extraordinarily low total heat release (THR of 7.6 kJ g?1).
Synthesis of high thermal stability polybenzoxazoles via ortho-imide-functional benzoxazine monomers
Zhang, Kan,Liu, Jia,Ohashi, Seishi,Ishida, Hatsuo,Liu, Xiaoyun,Han, Zhewen
, p. 1330 - 1338 (2015)
We report our work for preparing cross-linked polyimide via a series of imide functional benzoxazine resins as precursors. The structures of synthesized monomers have been confirmed by 1H NMR and FT-IR. Among this class of benzoxazine monomers, the ortho-imide functional benzoxazine resins show useful features both in the synthesis of benzoxazine monomers and the properties of the corresponding thermosets. For the cross-linked polyimides based on ortho-imide functional benzoxazine, an additional route is adopted to form a more thermally stable cross-linked polybenzoxazole with the release of carbon dioxide. The ortho-imide functional benzoxazine resins show the possibility to form high performance and even super high performance thermosets with low cost and easy processability. The thermal properties are evaluated by DSC and TGA.
“On water” nano-Cu2O-catalyzed CO-free one-pot multicomponent cascade cyanation-annulation-aminolysis reaction toward phthalimides
Wen, Xiaowei,Liu, Xiaojuan,Yang, Zhiqi,Xie, Menglan,Liu, Yuxi,Long, Lipeng,Chen, Zhengwang
supporting information, p. 1738 - 1743 (2021/03/14)
An efficient nano-Cu2O-catalyzed cascade multicomponent reaction of 2-halobenzoic acids and trimethylsilyl cyanide with diverse amines was developed using water as a solvent, affording versatileN-substituted phthalimide derivatives in moderate to excellent yields. This novel strategy features carbon monoxide gas-free, environmentally benign, one-pot multistep transformation, commercially available reagents, a cheap catalyst without any additives, wide functional group tolerance, and operational convenience.
One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols
Akai, Shuji,Ikawa, Takashi,Masuda, Shigeaki
, (2020/03/23)
Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.
Ru-Catalyzed Selective C-H Bond Hydroxylation of Cyclic Imides
Yuan, Yu-Chao,Bruneau, Christian,Dorcet, Vincent,Roisnel, Thierry,Gramage-Doria, Rafael
, p. 1898 - 1907 (2019/02/05)
We report on cyclic imides as weak directing groups for selective monohydroxylation reactions using ruthenium catalysis. Whereas acyclic amides are known to promote the hydroxylation of the C(sp2)-H bond enabling five-membered ring ruthenacycle intermediates, the cyclic imides studied herein enabled the hydroxylation of the C(sp2)-H bond via larger six-membered ruthenacycle intermediates. Furthermore, monohydroxylated products were exclusively obtained (even in the presence of overstoichiometric amounts of reagents), which was rationalized by the difficulty to accommodate coplanar intermediates once the first hydroxyl group was introduced into the substrate. The same reactivity was observed in the presence of palladium catalysts.
Synthesis of novel isoindolone-based medium-sized macromolecules and triazole containing heterocyclic compounds
Boddu, Lingaiah,Potlapati, Varakumar,Subhashini
, p. 3197 - 3205 (2019/11/11)
A series of novel isoindolone-based macromolecules of medium-sized heterocyclic rings, such as 7,8-dihydro-6H-benzo[4,5][1,6,3]dioxazonino[2,3-a]isoindol-14(9aH)-one derivatives (5a-l), were synthesized and its frame work incorporating with a triazole moiety on phenol, ie, 2-(4-((1-(2-methoxyphenyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)isoindoline-1,3-dione (9a-f) and also a triazole moiety on carboxylic acid, ie, (1-(2-methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl 4-(1,3-dioxoisoindolin-2-yl)benzoate derivatives (13a-e) with various substitutions on aryl ring system have synthesized. All the synthesized compounds were characterized and confirmed with IR, 1H NMR, 13C NMR, and ESI mass spectral analysis.
Stereoselective Synthesis of Functionalized Benzooxazepino[5,4- a] isoindolone Derivatives via Cesium Carbonate Catalyzed Formal [5 + 2] Annulation of 2-(2-Hydroxyphenyl)isoindoline-1,3-dione with Allenoates
Yao, Chao,Bao, Yishu,Lu, Tao,Zhou, Qingfa
supporting information, p. 2152 - 2155 (2018/04/30)
In this work, we present a strategy for the stereoselective synthesis of functionalized benzooxazepino[5,4-a]isoindolone derivatives via a Cs2CO3-catalyzed domino β-addition and γ-aldol reaction of 2-(2-hydroxyphenyl)isoindoline-1,3-dione derivatives with allenoates, which offers an avenue for a combination of the structural unity between benzooxazepine and isoindolone motifs in synthetically useful yields with high stereoselectivities under mild conditions. Remarkably, it is the first example of highly stereoselective Cs2CO3-catalyzed formal [5 + 2] annulation of 2-(2-hydroxyphenyl)isoindoline-1,3-dione with allenoates.
Synthesis of 2-aminophenols and heterocycles by Ru-catalyzed C-H mono- and dihydroxylation
Yang, Xinglin,Shan, Gang,Rao, Yu
supporting information, p. 2334 - 2337 (2013/07/04)
A novel and efficient synthesis of 2-aminophenols, 2-aminobenzene-1,3- diols, and heterocycles through Ru-catalyzed C-H mono- and dihydroxylation of anilides has been developed with a new directing group strategy. The reaction demonstrates excellent reactivity, regioselectivity, good functional group tolerance, and high yields.
Syntheses and characterization of nimesulide derivatives for dual enzyme inhibitors of both cyclooxygenase-1/2 and 5-lipoxygenase
Li, Yue,Chen, Shu-Han,Ou, Tian-Miao,Tan, Jia-Heng,Li, Ding,Gu, Lian-Quan,Huang, Zhi-Shu
experimental part, p. 2074 - 2083 (2011/05/05)
Cyclooxygenase-1/2 (COX-1/2) and 5-lipoxygenase (5-LOX) are enzymes in two different pathways in the inflammatory process. In the present study, a variety of new nimesulide derivatives were synthesized through incorporation of a 5-LOX pharmacophore into nimesulide followed with some structural modifications, which were then characterized for dual enzyme inhibitors for these two types of enzymes. Their structure-activity relationships (SARs) were studied, and compound 20f was found to be an excellent dual enzyme inhibitor. Its binding conformation and interaction mode were studied with molecular docking experiments. Compound 20f could become a lead compound for further development for potential anti-inflammatory drugs.
First synthesis of bi- and tricyclic α,β-unsaturated δ-oxacaprolactams from cyclic imines via ring-closing metathesis
Watzke, Martin,Schulz, Knut,Johannes, Katharina,Ullrich, Pasqual,Martens, Juergen
experimental part, p. 3859 - 3867 (2009/04/08)
A new class of α,β-unsaturated δ-oxacaprolactams was synthesized from imines as starting material. The synthetic procedure is based on an acyl chloride addition in the first step, followed by a ring-closing metathesis using a ruthenium catalyst. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
