915416-45-4Relevant academic research and scientific papers
Synthesis, Catalytic Activity and Comparative Leaching Studies of Calix[8]arene-Supported Pd-NHC Complexes for Suzuki-Miyaura Cross-Couplings
Abi Fayssal, Sandra,Buendia, Julien,Huc, Vincent,Labattut, Axel,Martini, Cyril,Naret, Timothée,Schulz, Emmanuelle
supporting information, p. 947 - 957 (2022/02/05)
A rapid and scalable synthesis of supported NHC?Pd(II)-pyridine complexes on a benzyloxycalix[8]arene macrocycle is reported. Their subsequent use in Suzuki-Miyaura benchmark reactions led to the optimisation of the nature of the ligands around the metal centre, delivering two very active precatalysts. They both promote the cross-coupling of challenging API precursors at low catalytic loadings, when used as insoluble species in EtOH as a green reaction solvent. Moreover, their activity has been shown to be comparable or even superior to that of more conventional homogeneous catalysts. Of main importance, a simple filtration of the insoluble supported catalysts after reaction afforded the lowest Pd contamination values in the target products, in some cases directly approaching the levels authorised by the industrial regulations. Offering furthermore the possibility of easy palladium recovery in the current context of its overconsumption, we are convinced that these calixarene-supported NHC-PEPPSI Pd complexes are valuable tools for the fine chemical industry, to prepare metal-free functionalised biaryl compounds in high yields, ranging from 76 to 94%. (Figure presented.).
Synthesis method of fluxapyroxad intermediate
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Paragraph 0033; 0039; 0045; 0047-0048, (2021/11/21)
The invention relates to a synthesis method of a fluxapyroxad intermediate. In order to solve the problems of harsh and complex conditions, high cost, unsafety and the like of the existing synthesis process, 3, 4, 5-trifluorophenylboronic acid and a compound with a structural formula shown in the specification react in the presence of a catalyst, alkali and a solvent to obtain the fluxapyroxad intermediate with the structural formula shown in the specification, R1 is nitro or amino, R2 is chlorine or bromine, and the catalyst is an amine catalyst and a phase transfer catalyst. According to the invention, the preparation process is simplified, the production cost is reduced, the safety is improved, the yield of the product is improved, the practical value is very high, the industrial production is facilitated, and the application prospect is wide.
Analysis of the Orbital and Electrostatic Contributions to the Lone Pair-Aromatic Interaction Using Molecular Rotors
Karki, Ishwor,Li, Ping,Madukwe, Daniel O.,Shimizu, Ken D.,Tibbetts, Gabriel S.,Vik, Erik C.
supporting information, p. 8179 - 8182 (2021/11/13)
The attractive interaction between carbonyl oxygens and the π-face of aromatic surfaces was studied using N-phenylimide molecular rotors. The C=O···Ar interactions could stabilize the transition states but were half the strength of comparable C=O···C=O interactions. The C=O···Ar interaction had a significant electrostatic component but only a small orbital delocalization component.
PROCESS FOR THE PREPARATION OF BIPHENYLAMINES
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Page/Page column 24-29, (2021/01/29)
The invention relates to a method for the preparation of 2-aminobiphenyls, key intermediates in the preparation of compounds of interest in the agrochemical industry. The process comprises reacting an ortho-substituted aniline and a phenylboro derivative in the presence of a base and a palladium catalyst, said palladium catalyst comprising a palladium source and a biphenyl phosphine ligand of formula (III) or a salt thereof
High Turnover Pd/C Catalyst for Nitro Group Reductions in Water. One-Pot Sequences and Syntheses of Pharmaceutical Intermediates
Gallou, Fabrice,Li, Xiaohan,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 8114 - 8118 (2021/10/25)
Commercially available Pd/C can be used as a catalyst for nitro group reductions with only 0.4 mol % Pd loading. The reaction can be performed using either silane as a transfer hydrogenating agent or simply a hydrogen balloon (μ1 atm pressure). With this technology, a series of nitro compounds was reduced to the desired amines in high chemical yields. Both the catalyst and surfactant were recycled several times without loss of reactivity.
Pd-Catalysed Suzuki-Miyaura cross-coupling of aryl chlorides at low catalyst loadings in water for the synthesis of industrially important fungicides
Goetz, Roland,Hashmi, A. Stephen K.,Orecchia, Patrizio,Petkova, Desislava Slavcheva,Rominger, Frank,Schaub, Thomas
supporting information, p. 8169 - 8180 (2021/11/01)
The Suzuki-Miyaura coupling reaction of electron-poor aryl chlorides in the synthesis of crop protection-relevant active ingredients in water is disclosed. Optimisation of the reaction conditions allowed running the reaction with 50 ppm of Pd-catalyst loading without an additional organic solvent in the cross-coupling reaction step in short reaction times. The system was optimised for the initial cross-coupling step of the large scale produced fungicides Boscalid, Fluxapyroxad and Bixafen up to 97% yield. It is also shown that the Suzuki-Miyaura reaction can be easily scaled up to 50 g using a simple product separation and purification using environmentally benign solvents in the work-up. To show the usability of this method, it was additionally applied in the three-step synthesis of the desired active ingredients.
Regiospecific Introduction of Halogens on the 2-Aminobiphenyl Subunit Leading to Highly Potent and Selective M3 Muscarinic Acetylcholine Receptor Antagonists and Weak Inverse Agonists
Fischer, Oliver,Hofmann, Josefa,Rampp, Hannelore,Kaindl, Jonas,Pratsch, Gerald,Bartuschat, Amelie,Taudte, R. Verena,Fromm, Martin F.,Hübner, Harald,Gmeiner, Peter,Heinrich, Markus R.
, p. 4349 - 4369 (2020/06/08)
Muscarinic M3 receptor antagonists and inverse agonists displaying high affinity and subtype selectivity over the antitarget M2 are valuable pharmacological tools and may enable improved treatment of chronic obstructive pulmonary disease (COPD), asthma, or urinary incontinence. On the basis of known M3 antagonists comprising a piperidine or quinuclidine unit attached to a biphenyl carbamate, 5-fluoro substitution was responsible for M3 subtype selectivity over M2, while 3′-chloro substitution substantially increased affinity through a σ-hole interaction. Resultantly, two piperidinyl-and two quinuclidinium-substituted biphenyl carbamates OFH243 (13n), OFH244 (13m), OFH3911 (14n), and OFH3912 (14m) were discovered, which display two-digit picomolar affinities with Ki values from 0.069 to 0.084 nM, as well as high selectivity over the M2 subtype (46-to 68-fold). While weak inverse agonistic properties were determined for the biphenyl carbamates 13m and 13n, neutral antagonism was observed for 14m and 14n and tiotropium under identical assay conditions.
Regiospecific Introduction of Halogens on the 2-Aminobiphenyl Subunit Leading to Highly Potent and Selective M3 Muscarinic Acetylcholine Receptor Antagonists and Weak Inverse Agonists
Fischer, Oliver,Hofmann, Josefa,Rampp, Hannelore,Kaindl, Jonas,Pratsch, Gerald,Bartuschat, Amelie,Taudte, R. Verena,Fromm, Martin F.,Hübner, Harald,Gmeiner, Peter,Heinrich, Markus R.
, p. 4349 - 4369 (2020/06/08)
Muscarinic M3 receptor antagonists and inverse agonists displaying high affinity and subtype selectivity over the antitarget M2 are valuable pharmacological tools and may enable improved treatment of chronic obstructive pulmonary disease (COPD), asthma, or urinary incontinence. On the basis of known M3 antagonists comprising a piperidine or quinuclidine unit attached to a biphenyl carbamate, 5-fluoro substitution was responsible for M3 subtype selectivity over M2, while 3′-chloro substitution substantially increased affinity through a σ-hole interaction. Resultantly, two piperidinyl- A nd two quinuclidinium-substituted biphenyl carbamates OFH243 (13n), OFH244 (13m), OFH3911 (14n), and OFH3912 (14m) were discovered, which display two-digit picomolar affinities with Ki values from 0.069 to 0.084 nM, as well as high selectivity over the M2 subtype (46-to 68-fold). While weak inverse agonistic properties were determined for the biphenyl carbamates 13m and 13n, neutral antagonism was observed for 14m and 14n and tiotropium under identical assay conditions.
A 3 ', 4', 5' - trifluoro -2 - amino biphenyl chemical synthesis method
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, (2019/07/11)
The invention discloses a 3 ', 4', 5 '- trifluoro - 2 - amino biphenyl chemical synthesis method, it to 3, 4, 5 - trifluoro bromobenzene as the starting material, passes through formatting reaction, reaction and coupling reaction to obtain a sediment 3', 4 ', 5' - trifluoro - 2 - nitro-biphenyl, 3 ', 4', 5 '- trifluoro - 2 - nitro-biphenyl through catalytic reduction reaction to obtain the target product 3', 4 ', 5' - trifluoro - 2 - phenylaniline. The present invention provides compound 3 ', 4', 5' - trifluoro - 2 - amino biphenyl synthesis of new routes, the advantages of the simple process operation, mild reaction conditions, high yield, is simple in separation purification. Wherein the 3 ', 4', 5' - trifluoro - 2 - nitro-biphenyl synthesis in the process, the catalyst consumption is low, and the production cost is reduced, more suitable for large-scale industrial application.
