71907-23-8Relevant academic research and scientific papers
Bimetallic Cooperative Catalysis for Decarbonylative Heteroarylation of Carboxylic Acids via C-O/C-H Coupling
Liu, Chengwei,Ji, Chong-Lei,Zhou, Tongliang,Hong, Xin,Szostak, Michal
supporting information, p. 10690 - 10699 (2021/04/09)
Cooperative bimetallic catalysis is a fundamental approach in modern synthetic chemistry. We report bimetallic cooperative catalysis for the direct decarbonylative heteroarylation of ubiquitous carboxylic acids via acyl C-O/C-H coupling. This novel catalytic system exploits the cooperative action of a copper catalyst and a palladium catalyst in decarbonylation, which enables highly chemoselective synthesis of important heterobiaryl motifs through the coupling of carboxylic acids with heteroarenes in the absence of prefunctionalization or directing groups. This cooperative decarbonylative method uses common carboxylic acids and shows a remarkably broad substrate scope (>70 examples), including late-stage modification of pharmaceuticals and streamlined synthesis of bioactive agents. Extensive mechanistic and computational studies were conducted to gain insight into the mechanism of the reaction. The key step involves intersection of the two catalytic cycles via transmetallation of the copper–aryl species with the palladium(II) intermediate generated by oxidative addition/decarbonylation.
Synthesis and hplc-ecd study of cytostatic condensed o,n-heterocycles obtained from 3-aminoflavanones
Szappanos,Mándi, Attila,Gulácsi, Katalin,Lisztes, Erika,István Tóth, Balázs,Bíró, Tamás,Kónya-ábrahám, Anita,Kiss-Szikszai, Attila,Bényei, Attila,Antus, Sándor,Kurtán, Tibor
, p. 1 - 42 (2020/10/30)
Racemic chiral O,N-heterocycles containing 2-arylchroman or 2-aryl-2H-chromene subunit condensed with morpholine, thiazole, or pyrrole moieties at the C-3-C-4 bond were synthesized with various substitution patterns of the aryl group by the cyclization of cis- or trans-3- aminoflavanone analogues. The 3-aminoflavanone precursors were obtained in a Neber rearrangement of oxime tosylates of flavanones, which provided the trans diastereomer as the major product and enabled the isolation of both the cis- and trans-diastereomers. The cis- and transaminoflavanones were utilized to prepare three diastereomers of 5-aryl-chromeno[4,3- b][1,4]oxazines. Antiproliferative activity of the condensed heterocycles and precursors was evaluated against A2780 and WM35 cancer cell lines. For a 3-(N-chloroacetylamino)-flavan-4-ol derivative, showing structural analogy with acyclic acid ceramidase inhibitors, 0.15 μM, 3.50 μM, and 6.06 μM IC50 values were measured against A2780, WM35, and HaCat cell lines, and apoptotic mechanism was confirmed. Low micromolar IC50 values down to 2.14 μM were identified for the thiazole- and pyrrole-condensed 2H-chromene derivatives. Enantiomers of the condensed heterocycles were separated by HPLC using chiral stationary phase, HPLC-ECD spectra were recorded and TDDFT-ECD calculations were performed to determine the absolute configuration and solution conformation. Characteristic ECD transitions of the separated enantiomers were correlated with the absolute configuration and effect of substitution pattern on the HPLC elution order was determined.
Method of coupling, and the coupling method using the aromatic group-substituted heterocyclic compound
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Paragraph 0292-0297; 0299, (2020/09/17)
Provided is an easy method (coupling method) capable of easily synthesizing a compound group in which aromatic molecules and aromatic molecules are coupled, a compound group in which aromatic molecules and alkene molecules are coupled, and the like without producing halogen waste and without the need to use scarce and expensive palladium. A compound (A) shown by general formula (A): Ar-H and a compound (B1) shown by general formula (B1): RaOCO-Ar', a compound (B2) shown by general formula (B2): RbCH=C(Ar")2, or a compound (B3) shown by general formula (B3): RcOCOCH=C(Ar")2 are reacted in the presence of a nickel compound.
Br?nsted acid-catalysed conjugate addition of photochemically generated α-amino radicals to alkenylpyridines
Hepburn, Hamish B.,Melchiorre, Paolo
supporting information, p. 3520 - 3523 (2016/03/04)
The conjugate addition of α-amino radicals to alkenylpyridines has been accomplished by the synergistic merger of Br?nsted acid and visible light photoredox catalysis. Key to reaction development was the protonation of the alkenylpyridines that transientl
Access to 2-(het)aryl and 2-styryl benzoxazoles via palladium-catalyzed aminocarbonylation of aryl and vinyl bromides
Neumann, Karoline T.,Lindhardt, Anders T.,Bang-Andersen, Benny,Skrydstrup, Troels
supporting information, p. 2094 - 2097 (2015/05/13)
A sequential one-pot procedure for the synthesis of either 2-(hetero)aryl or 2-styryl benzoxazoles is reported, starting from aryl and vinyl bromides, respectively, involving an initial aminocarbonylation with 2-aminophenols as nucleophiles followed by an acid mediated ring closure to generate the heterocycle. The methodology displays a broad substrate scope in moderate to excellent yields and can be exploited for 13C-isotope labeling. Finally, this carbonylative protocol was applied to the synthesis of a potential Alzheimer's plaque binder and a selective PPAR antagonist including site-specific labeling with 13C-carbon monoxide.
BF3·Et2O-promoted cleavage of the Csp-Csp2 bond of 2-propynolphenols/anilines: Route to C2-alkenylated benzoxazoles and benzimidazoles
Song, Xian-Rong,Qiu, Yi-Feng,Song, Bo,Hao, Xin-Hua,Han, Ya-Ping,Gao, Pin,Liu, Xue-Yuan,Liang, Yong-Min
, p. 2263 - 2271 (2015/03/18)
A novel BF3·Et2O-promoted tandem reaction of easily prepared 2-propynolphenols/anilines and trimethylsilyl azide is developed to give C2-alkenylated benzoxazoles and benzimidazoles in moderate to good yields. Most reactions could be accomplished in 30 min at room temperature. This tandem process involves a Csp-Csp2 bond cleavage and a C-N bond formation. Moreover, both tertiary and secondary propargylic alcohols with diverse functional groups were tolerated under the mild conditions.
C-H alkenylation of azoles with enols and esters by nickel catalysis
Meng, Lingkui,Kamada, Yuko,Muto, Kei,Yamaguchi, Junichiro,Itami, Kenichiro
supporting information, p. 10048 - 10051 (2013/10/01)
Rather u(Ni)que: Two new C-H alkenylation reactions, that is C-H/Ci￡O alkenylation and decarbonylative C-H alkenylation, of azoles are uniquely catalyzed by Ni/dcype. These azole alkenylation reactions are successfully applied to the convergent formal synthesis of siphonazoleB.
