4165-60-0Relevant academic research and scientific papers
Gold(I)-Catalyzed Oxidative 1,4-Additions of 3-En-1-ynamide with Nitrones via Carbon- versus Nitrogen-Addition Chemoselectivity
Tanpure, Sudhakar Dattatray,Kale, Balaji S.,Liu, Rai-Shung
supporting information, p. 1394 - 1399 (2021/02/20)
This work reports gold-catalyzed 1,4-oxofunctionalizations of 3-en-1-ynamides with nitrones, yielding two distinct E-configured products. We obtained 1,4-oxoarylation products from 3-en-1-ynamides bearing C(4)-electron-donating substituents and 1,4-oxoamination products from those analogues bearing C(4)-aryl substituents. We propose that if vinylgold carbenes are stable, imines undergo a para-arylation on these gold carbenes. If vinylgold carbenes are highly electron-deficient, this N-attack is irreversible to enable 1,4-oxoaminations.
Synthesis of Unprotected and Highly Substituted Indoles by the Ruthenium(II)-Catalyzed Reaction of Phenyl Isocyanates with Diaryl/Diheteroaryl Alkynes/Ethyl-3-phenyl Propiolates
Kumar, Amrendra,Tadigoppula, Narender
supporting information, p. 8 - 12 (2021/01/13)
A one-pot transformation has been developed for the synthesis of unprotected and highly substituted indoles by an in situ installed carbamide-directed Ru(II)-catalyzed intermolecular oxidative annulation of phenyl isocyanates with diaryl/diheteroaryl alkynes/ethyl phenyl propiolates in the presence of Cu(OAc)2·H2O as an oxidant and AgSbF6 as an additive at 120 °C within 3 h.
Benzocarbazole Synthesis via Visible-Light-Accelerated Rh(III)-Catalyzed C-H Annulation of Aromatic Amines with Bicyclic Alkenes
Wang, Yichun,Jia, Deyang,Zeng, Jing,Liu, Yuming,Bu, Xiubin,Yang, Xiaobo
supporting information, p. 7740 - 7745 (2021/10/20)
A visible-light-accelerated Rh(III)-catalyzed C-H annulation of aromatic amines with bicyclic alkenes for the synthesis of benzocarbazole derivatives was developed. In this approach, with the cooperation of rhodium catalysis and visible-light irradiation, various aromatic amines reacted with oxabicyclic alkenes and azabicyclic alkenes smoothly at room temperature, delivering the corresponding bridged oxa or aza tetrahydro benzocarbazoles in good to excellent yields. Moreover, a series of benzo[b]carbazoles were synthesized conveniently through further aromatization in one pot. The potential of this method was demonstrated via directing-group removal, derivatization, a scale-up reaction, and fluorescence investigations.
Copper-Catalyzed Modular Access to N-Fused Polycyclic Indoles and 5-Aroyl-pyrrol-2-ones via Intramolecular N—H/C—H Annulation with Alkynes: Scope and Mechanism Probes
Liu, Yan-Hua,Song, Hong,Zhang, Chi,Liu, Yue-Jin,Shi, Bing-Feng
supporting information, p. 1545 - 1552 (2020/09/09)
Copper-catalyzed intramolecular N—H/C—H annulation with alkynes has been developed. A variety of densely functionalized heterocycles, such as pyrrolo[1,2-a]indoles, indolo[1,2-c]quinazolin-2-ones, oxazolo[3,4-a]indoles, and imidazo[1,5-a]indoles, were synthesized in an atom- and step-economical manner, owing to the high modularized feature of aniline moiety, the linker moiety, as well as the alkyne moiety. By simply changing the oxidant from di-tert-butyl peroxide (DTBP) to 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), the reaction could readily be transformed to the aminooxygenation pathway, which grabs one oxygen atom from the TEMPO to generate 5-aroyl-pyrrol-2-ones. Mechanistic experiments indicate that vinyl radical is involved in this reaction and an amidyl-radical-initiated radical cascade might be responsible for this transformation.
A New Class of Lanthanide Complexes with Three Ligand Centered Radicals: NMR Evaluation of Ligand Field Energy Splitting and Magnetic Coupling
Hiller, Markus,Sittel, Thomas,Wadepohl, Hubert,Enders, Markus
supporting information, p. 10668 - 10677 (2019/07/12)
Combination of three radical anionic Ph-BIAN ligands (Ph-BIAN=bis-(phenylimino)-acenaphthenequinone) with lanthanoid ions leads to a series of homoleptic, six-coordinate complexes of the type Ln(Ph-BIAN)3. Magnetic coupling data were measured by paramagnetic solution NMR spectroscopy. Combining 1H NMR with 2H NMR of partially deuterated compounds allowed a detailed study of the magnetic susceptibility anisotropies over a large temperature range. The observed chemical shifts were separated into ligand- and metal-centered contributions by comparison with the Y analogue (diamagnetic at the metal). The metal-centered contributions of the complexes with the paramagnetic ions could then be separated into pseudocontact and Fermi contact shifts. The latter is large within the Ph-BIAN scaffold, which shows that magnetic coupling is significant between the lanthanide ion and the radical ligand. Pseudocontact shifts were further correlated to structural data obtained from X-ray diffraction experiments. Ligand-field parameters were determined by fitting the temperature dependence of the observed magnetic susceptibility anisotropies. The electronic structure determined by this approach shows, that the Er and Tm analogues are candidates for single molecule magnets (SMM). These results demonstrate the possibilities for the application of NMR spectroscopy in investigations of paramagnetic systems in general and single molecule magnets in particular.
Halogenated anilines as novel natural products from a marine biofilm forming microalga
Baumeister, Tim U. H.,Staudinger, Mona,Wirgenings, Marino,Pohnert, Georg
, p. 11948 - 11951 (2019/10/14)
The toxic halogenated anilines 2,4,6-tribromoaniline, 2,4,6-trichloroaniline and their dibromochloro and bromodichloro derivatives were considered as compounds of exclusive synthetic origin. Labeling studies and kinetic experiments confirmed that these substances are also biosynthesized by a marine biofilm forming microalga. They represent a novel class of halogenated natural products.
Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
supporting information, p. 237 - 241 (2019/01/10)
Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
Ruthenium(II)-Catalyzed Oxidative Double C-H Activation and Annulation Reaction: Synthesis of Indolo[2,1- a]isoquinolines
Borthakur, Somadrita,Sarma, Bipul,Gogoi, Sanjib
supporting information, p. 7878 - 7882 (2019/10/11)
The first metal-catalyzed double aryl C(sp2)-H bond activation of antipyrine and alkyne annulation reaction is reported. This Ru(II)-catalyzed reaction was accomplished in the presence of 20 mol % phosphine ligand tricyclohexylphosphine tetrafluoroborate to afford indolo[2,1-a]isoquinolines that are very important compounds because of their bioactivity and interesting optical properties.
Stable isotope deuterium labeled sulfanilamide drug and preparation method thereof
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Paragraph 0026; 0027; 0028; 0029, (2018/04/26)
The invention belongs to the technical field of chemical synthesis, and specifically relates to a stable isotope deuterium labeled sulfanilamide drug and a preparation method thereof. The preparationmethod comprises the following steps: (1) subjecting benzene-d6 (I) to a nitratlon reaction so as to prepare deuterium labeled nitrobenzene-d5 (II); (2) reducing nitro of the deuterium labeled nitrobenzene-d5 (II) so as to prepare deuterium labeled aniline-d5 (III); (3) under the conditions of anhydrous sodium acetate and glacial acetic acid, subjecting the deuterium labeled aniline-d5 (III) and acetic anhydride to a reaction so as to prepare deuterium labeled N-acetanilide-d5 (IV); (4) subjecting the deuterium labeled N-acetanilide-d5 (IV) and chlorosulfonic acid to a reaction so as to prepare deuterium labeled 1-chlorosulfonyl-4-acetamidobenzene-d4 (V); and (5) allowing R to substitute chlorine of the deuterium labeled 1-chlorosulfonyl-4-acetamidobenzene-d4 (V), and carrying out hydrolysis so as to prepare an isotope deuterium labeled sulfanilamide drug (VII). The preparation method provided by the invention has the advantages of simple reaction conditions, short reaction time, highconversion efficiency, strong economy, and applicability to mass synthesis.
Ru(II)-Catalyzed C-H Activation and Annulation Reaction via Carbon-Carbon Triple Bond Cleavage
Prakash, Rashmi,Bora, Bidisha R.,Boruah, Romesh C.,Gogoi, Sanjib
supporting information, p. 2297 - 2300 (2018/04/30)
An unprecedented Ru(II)-catalyzed C-H activation and annulation reaction, which proceeds via C-C triple bond cleavage, is reported. This reaction of 2-phenyldihydrophthalazinediones with alkynes, which works most efficiently in the presence of bidented ligand 1,3-bis(diphenylphosphino)propane, affords good yields of substituted quinazolines.
