1759-68-8Relevant academic research and scientific papers
Exploring the coordination chemistry of 1-benzoyl-4,5-dihydro-3,5- bis(trifluoromethyl)-1H-pyrazol-5-ol to copper
Someya, Chika I.,Inoue, Shigeyoshi,Enthaler, Stephan
, p. 131 - 134 (2013)
The coordination chemistry of the ligand 1-benzoyl-4,5-dihydro-3,5- bis(trifluoromethyl)-1H-pyrazol-5-ol (1a) has been recently investigated. In dependency of the metal (e.g., nickel, zinc, molybdenum) and the added co-ligand (phosphanes, pyridines, amine
CuBr-catalysed oxidative desulfurisation of thiobenzamides
Cheng, Dongping,Sun, Ruirui,Yan, Jizhong
, p. 210 - 212 (2012)
An efficient oxidative desulfurisation of thioamides by CuBr/TBHP is reported. Thioamides containing alkyl or aryl on the nitrogen undergo desulfurisation and give amides with good yields. Thioamides not containing substituent on the nitrogen undergo desulfurisation and give 1,2,4-thiadiazoles in moderate to good yields.
Molecular rearrangement of 1-substituted 3-aminoquinoline-2,4-diones in their reaction with urea and nitrourea synthesis and transformations of reaction intermediates
Klasek, Antonin,Lyoka, Antonin,Holcapek, Michal,Kovar, Michal,Hoza, Ignac
, p. 1251 - 1260 (2006)
1-Substituted 3-alkyl/aryl-3-amino-1H,3H-quinoline-2,4-diones (6) react with nitrourea to give 3-ureido-1H,3H-quinoline-2,4-diones (10), 9b-hydroxy-3,3a,5,9b-tetrahydro-1H-imidazo[4,5-c]quinoline-2,4-diones (11), and 3,3a-dihydro-5H-imidazo[4,5-c]quinoline-2,4-diones (12). Compounds 11 were dehydrated to 12 by the action of phosphorus pentoxide. All three types of compounds rearrange in boiling acetic acid to give three different types of products of molecular rearrangement. A proposed reaction mechanism is discussed.
Gas-phase formation of protonated benzene during collision-induced dissociation of certain protonated mono-substituted aromatic molecules produced in electrospray ionization
Li, Min,Lin, Mingxiang,Rustum, Abu M.
, p. 1707 - 1716 (2010)
Protonated benzene, C6H+7, has been studied extensively to understand the structure and energy of a protonated organic molecule in the gas phase. The formation of C6H+7 is either through direct protonation of benzene, i.e., chemical ionization, or through fragmentation of certain radical cations produced from electron ionization or photon ionization. We report a novel observation of C6H+7 as a product ion formed in the collision-induced dissociation (CID) of protonated benzamide and related molecules produced via electrospray ionization (ESI). The formation of C6H+7 from these even-electron precursor ions during the CID process, which has not been previously reported, is proposed to occur from the protonated molecules via a proton migration in a five-membered ring intermediate followed by the cleavage of the mono-substituent C-C bond and concurrent formation of an ion-molecule complex. This unique mechanism has been scrutinized by examining some deuterated molecules and a series of structurally related model compounds. This finding provides a convenient mean to generate C6H+7, a reactive intermediate of considerable interest, for further physical or chemical investigation. Further studies indicate that the occurrence of C6H+7 in liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) appears to be a rather common phenomenon for many compounds that contain 'benzoyl-type' moieties. Hence, the observation of the C6H+7 ion in LC/ESI-MS/MS can be used as an informative fragmentation pathway which should facilitate the identification of a great number of compounds containing the 'benzoyl-type' and similar structural features. These compounds are frequently present in food and pharmaceutical products as leachable impurities that require strict control and rapid elucidation of their identities.
Facile synthesis of phosphaamidines and phosphaamidinates using nitrilium ions as an imine synthon
Van Dijk, Tom,Burck, Sebastian,Rong, Mark K.,Rosenthal, Amos J.,Nieger, Martin,Slootweg, J. Chris,Lammertsma, Koop
, p. 9068 - 9071 (2014)
Readily accessible nitrilium triflates are convenient imine building blocks for the expedient synthesis of a novel class of 1,3-P,N ligands as demonstrated for the reaction with primary phosphanes. This procedure allows variation of all substituents. X-ray crystal structures are reported for nitrilium ions, phosphaamidines, and three phosphaamidinate complexes. The lithium phosphaamidinate is N coordinated and its reaction with [AuCl(tht)] (tht=tetrahydrothiophene) gives a unique P-bridged gold trimer, while a P,N-bidentate complex results from [{RhCl(cod)}2]. The nitrilium ion methodology allows extension of the 1,3-P,N motive to bis(imino)phosphanes, which are the neutral phosphorus analogues of the valuable β-diketiminate ligand.
AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
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Paragraph 0008-0009; 0063-0064, (2022/03/04)
The present invention generally relates to a process for selective and direct activation and subsequent amidation of aliphatic and aromatic carboxylic acids to afford an amide R3CONR1R2. That the process is capable of delivering gaseous or low-boiling point amines provides a major advantage over existing methodologies, which involves an intermediate of triacyloxyborane-amine complex [(R3CO2)3—B—NHR1R2]. This procedure readily produces primary, secondary, and tertiary amides, and is compatible with the chirality of the acid and amine involved. The preparation of known pharmaceutical molecules and intermediates has also been demonstrated.
Photocatalysis in Aqueous Micellar Media Enables Divergent C-H Arylation and N-Dealkylation of Benzamides
Cybularczyk-Cecotka, Martyna,Predygier, J?drzej,Crespi, Stefano,Szczepanik, Joanna,Giedyk, MacIej
, p. 3543 - 3549 (2022/03/27)
Photocatalysis in aqueous micellar media has recently opened wide avenues to activate strong carbon-halide bonds. So far, however, it has mainly explored strongly reducing conditions, restricting the available chemical space to radical or anionic reactivity. Here, we demonstrate a controllable, photocatalytic strategy that channels the reaction of chlorinated benzamides via either a radical or a cationic pathway, enabling a chemodivergent C-H arylation or N-dealkylation. The catalytic system operates under mild conditions with methylene blue as a photocatalyst and blue LEDs as the light source. Factors determining the reactivity of substrates, their selectivity, and preliminary mechanistic studies are presented.
Crystal structure of 1-(2,4,6-trichlorobenzoyloxy) benzotriazole (TCB-OBt): observation of uncommon intermolecular oxygen-oxygen interaction and synthetic application in amidation
Dolai, Gobinda,Giri, Rajat Subhra,Mandal, Bhubaneswar,Roy, Sayanta,Sen, Srijit
, p. 19804 - 19811 (2021/11/12)
Herein, we investigated the supramolecular assembly of a modified Yamaguchi reagent TCB-OBt. Interestingly, each molecule is interconnected through novel chalcogen-chalcogen (O?O) interaction, π-π stacking, and aromatic C-H?O interaction. Hirshfeld surface analysis confirmed the existence of uncommon O?O interactions. A well-organized supramolecular layer structure and helical arrangement were observed in the crystal structure. TCB-OBt crystallized in the O-substituted desmotropic form. DFT calculations suggest that the O-substituted form is more stable than theN-substituted form (TCB-(N)-OBt). Morphology analysis indicates the formation of a fantastically well organized, continuous block-shaped system. Furthermore, the designed reagent works as an efficient activating reagent for amide bond formation with good yields under mild reaction conditions. Use of this reagent avoided intractable acid chlorides, and this new mixed-anhydride-based reagent may further be applicable for many other organic transformations.
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Zhang, Xiao,Rovis, Tomislav
supporting information, p. 21211 - 21217 (2021/12/27)
Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
Weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis
Park, Jin,Park, Sehoon,Jang, Gwang Seok,Kim, Ran Hui,Jung, Jaehoon,Woo, Sang Kook
supporting information, p. 9995 - 9998 (2021/10/06)
The selective rearrangement of oxaziridines to amidesviaa single electron transfer (SET) pathway is unexplored. In this study, we present a weak base-promoted selective rearrangement of oxaziridines to amidesviavisible-light photoredox catalysis. The developed method shows excellent functional group tolerance with a broad substrate scope and good to excellent yields. Furthermore, control experiments and density functional theory (DFT) calculations are performed to gain insight into the reactivity and selectivity.
