5635-16-5Relevant academic research and scientific papers
A Unified Approach for Divergent Synthesis of Heterocycles via TMSOTf-Catalyzed Formal [3+2] Cycloaddition of Electron-Rich Alkynes
Chen, Ping,Cao, Wei,Li, Xiangqian,Shi, Dayong
supporting information, p. 4789 - 4794 (2021/09/02)
We present a synthetic protocol for the construction of polysubstituted five-membered heterocycles via TMSOTf-catalyzed formal [3+2] cycloaddition of electron-rich alkynes, which features free from any metal, atom economy and water as the main by-product. Furthermore, alkenyl ether adduct has been verified as the key intermediate. Notably, by utilizing this approach, we can synthesize a broad range of polysubstituted furans, thiophenes and pyrroles, and extend this transformation to deliver fused-polyheterocycles. This reaction can be achieved on a gram scale and the corresponding products are intermediates for producing diverse potentially useful scaffolds. (Figure presented.).
Palladium-Catalyzed Cross-Coupling of Alkenyl Carboxylates
Becica, Joseph,Heath, Oliver R. J.,Leitch, David C.,Zheng, Cameron H. M.
supporting information, p. 17277 - 17281 (2020/07/31)
Carboxylate esters have many desirable features as electrophiles for catalytic cross-coupling: they are easy to access, robust during multistep synthesis, and mass-efficient in coupling reactions. Alkenyl carboxylates, a class of readily prepared non-aromatic electrophiles, remain difficult to functionalize through cross-coupling. We demonstrate that Pd catalysis is effective for coupling electron-deficient alkenyl carboxylates with arylboronic acids in the absence of base or oxidants. Furthermore, these reactions can proceed by two distinct mechanisms for C?O bond activation. A Pd0/II catalytic cycle is viable when using a Pd0 precatalyst, with turnover-limiting C?O oxidative addition; however, an alternative pathway that involves alkene carbopalladation and β-carboxyl elimination is proposed for PdII precatalysts. This work provides a clear path toward engaging myriad oxygen-based electrophiles in Pd-catalyzed cross-coupling.
Two-step synthesis of π-expanded maleimides from 3,4-diphenylfuran-2(5 H)-ones
Kang, Yang,Zhang, Wei,Wang, Tao,Liang, Yong,Zhang, Zunting
, p. 12387 - 12398 (2019/10/11)
An efficient two-step synthesis of -expanded maleimide derivatives was reported, which proceeded via a photoinduced dehydrogenative annulation of 3,4-diphenylfuran-2(5H)-ones in EtOH at room temperature for 5 h under an argon atmosphere, followed by inter
Structure-activity relationship of celecoxib and rofecoxib for the membrane permeabilizing activity
Yamakawa, Naoki,Suzuki, Koichiro,Yamashita, Yasunobu,Katsu, Takashi,Hanaya, Kengo,Shoji, Mitsuru,Sugai, Takeshi,Mizushima, Tohru
, p. 2529 - 2534 (2014/05/06)
Non-steroidal anti-inflammatory drugs (NSAIDs) achieve their anti-inflammatory effect by inhibiting cyclooxygenase activity. We previously suggested that in addition to cyclooxygenase-inhibition at the gastric mucosa, NSAID-induced gastric mucosal cell death is required for the formation of NSAID-induced gastric lesions in vivo. We showed that celecoxib exhibited the most potent membrane permeabilizing activity among the NSAIDs tested. In contrast, we have found that the NSAID rofecoxib has very weak membrane permeabilizing activity. To understand the membrane permeabilizing activity of coxibs in terms of their structure-activity relationship, we separated the structures of celecoxib and rofecoxib into three parts, synthesized hybrid compounds by substitution of each of the parts, and examined the membrane permeabilizing activities of these hybrids. The results suggest that the sulfonamidophenyl subgroup of celecoxib or the methanesulfonylphenyl subgroup of rofecoxib is important for their potent or weak membrane permeabilizing activity, respectively. These findings provide important information for design and synthesis of new coxibs with lower membrane permeabilizing activity.
Design of fluorine-containing 3,4-diarylfuran-2(5H)-ones as selective COX-1 inhibitors
Uddin, Md. Jashim,Elleman, Anna V.,Ghebreselasie, Kebreab,Daniel, Cristina K.,Crews, Brenda C.,Nance, Kellie D.,Huda, Tamanna,Marnett, Lawrence J.
supporting information, p. 1254 - 1258 (2015/04/27)
We report the design and synthesis of fluorine-containing cyclooxygenase-1 (COX-1)-selective inhibitors to serve as prototypes for the development of a COX-1-targeted imaging agent. Deletion of the SO2CH3 group of rofecoxib switches the compound from a COX-2- to a COX-1-selective inhibitor, providing a 3,4-diarylfuran-2(5H)-one scaffold for structure-activity relationship studies of COX-1 inhibition. A wide range of fluorine-containing 3,4-diarylfuran-2(5H)-ones were designed, synthesized, and tested for their ability to selectively inhibit COX-1 in purified protein and human cancer cell assays. Compounds containing a fluoro-substituent on the C-3 phenyl ring and a methoxy-substituent on the C-4 phenyl ring of the 3,4-diarylfuran-2(5H)-one scaffold were the best COX-1-selective agents of those evaluated, exhibiting IC50s in the submicromolar range. These compounds provide the foundation for development of an agent to facilitate radiologic imaging of ovarian cancer expressing elevated levels of COX-1.
New compounds for inhibiting differentiation of osteoclast and pharmaceutical composition comprising thereof
-
Paragraph 0260; 0261; 0262, (2014/02/16)
New compounds and pharmaceutical compositions comprising active ingredients having inhibition effects on osteoclast differentiation are provided. The pharmaceutical compositions comprising the new compounds can be used as medicines for treating metabolic bone diseases such as bone metastatic cancer, solid cancer bone metastasis, musculoskeletal complication by solid cancer bone metastasis, hypercalcemia by malignant tumor, multiple myeloma, primary bone tumor, osteoporosis, rheumatoid arthritis, osteoarthritis, periodontal disease, inflammatory resorption of alveolar bone, inflammatory resorption of bone, and Paget's disease.
Optimizing P,N-bidentate ligands for oxidative gold catalysis: Efficient intermolecular trapping of α-oxo gold carbenes by carboxylic acids
Ji, Kegong,Zhao, Yulong,Zhang, Liming
supporting information, p. 6508 - 6512 (2013/07/27)
Control confirmed: Optimization of P,N-bidentate ligands (L) reveals the importance of conformation control for intermolecular trapping of reactive α-oxo gold carbene intermediates. As a result, the highly efficient and broadly applicable synthesis of car
Synthesis of substituted 3-iodocoumarins and 3-iodobutenolides via electrophilic iodocyclization of ethoxyalkyne diols
Reddy, Maddi Sridhar,Thirupathi, Nuligonda,Hari Babu, Madala,Puri, Surendra
, p. 5878 - 5888 (2013/07/26)
A convenient and general synthesis of various 4-substituted 3-iodocoumarins and 4,5-disubstituted 3-iodobutenolides is described via an exclusive 6-endo-dig iodocyclization of 3-ethoxy-1-(2-alkoxyphenyl)-2-yn-1-ols and 5-endo-dig iodocyclization of 1-alkoxy-4-ethoxy-3-yn-1,2-diols, respectively. The reaction is carried out under very mild conditions using I2 in CH2Cl2 or toluene at room temperature. Oxygens in OMe and OMOM groups were used as efficient nucleophiles for this intramolecular cyclization to obtain the products in good to excellent yields.
Efficient direct asymmetric vinylogous Michael addition reactions of γ-butenolides to chalcones catalyzed by vicinal primary-diamine salts
Wang, Junfeng,Qi, Chao,Ge, Zemei,Cheng, Tieming,Li, Runtao
supporting information; experimental part, p. 2124 - 2126 (2010/07/13)
The first direct organocatalytic asymmetric vinylogous Michael addition reactions of γ-butenolides to chalcones have been developed by using chiral 1,2-diaminocyclohexane as a novel organocatalyst via a di-iminium transition state to provide syn-Michael p
Au-catalyzed isomerization of cyclopropenes: a novel approach to indene derivatives
Li, Changkun,Zeng, Yi,Wang, Jianbo
scheme or table, p. 2956 - 2959 (2009/08/09)
AuPPh3Cl/AgOTf-catalyzed reaction of cyclopropenes is found to be highly efficient, giving indene derivatives in high yields. The reaction is suggested to proceed through gold vinyl carbenoid intermediate.
