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101.
Tomáš Čarný Dr. Ronan Rocaboy Dr. Antonin Clemenceau Prof. Dr. Olivier Baudoin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19142-19146
The 1,4-palladium shift strategy allows the functionalization of remote C−H bonds that are difficult to reach directly. Reported here is a domino reaction proceeding by C(sp3)−H activation, 1,4-palladium shift, and amino- or alkoxycarbonylation, which generates a variety of amides and esters bearing a quaternary β-carbon atom. Mechanistic studies showed that the aminocarbonylation of the σ-alkylpalladium intermediate arising from the palladium shift is fast using PPh3 as the ligand, and leads to the amide rather than the previously reported indanone product. 相似文献
102.
Dr. Marion Daniel-Bertrand Sébastien Garcia-Argote Dr. Alberto Palazzolo Dr. Irene Mustieles Marin Dr. Pier-Francesco Fazzini Dr. Simon Tricard Dr. Bruno Chaudret Dr. Volker Derdau Dr. Sophie Feuillastre Dr. Grégory Pieters 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21300-21306
Radiolabelling is fundamental in drug discovery and development as it is mandatory for preclinical ADME studies and late-stage human clinical trials. Herein, a general, effective, and easy to implement method for the multiple site incorporation of deuterium and tritium atoms using the commercially available and air-stable iridium precatalyst [Ir(COD)(OMe)]2 is described. A large scope of pharmaceutically relevant substructures can be labelled using this method including pyridine, pyrazine, indole, carbazole, aniline, oxa-/thia-zoles, thiophene, but also electron-rich phenyl groups. The high functional group tolerance of the reaction is highlighted by the labelling of a wide range of complex pharmaceuticals, containing notably halogen or sulfur atoms and nitrile groups. The multiple site hydrogen isotope incorporation has been explained by the in situ formation of complementary catalytically active species: monometallic iridium complexes and iridium nanoparticles. 相似文献
103.
Dr. Shao-Ping Zheng Dr. Ji-Jun Jiang Dr. Arie van der Lee Dr. Mihail Barboiu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(43):19082-19088
Transmembrane protein channels are an important inspiration for the design of artificial ion channels. Their dipolar structure helps overcome the high energy barrier to selectively translocate water and ions sharing one pathway, across the cell membrane. Herein, we report that the amino-imidazole (Imu) amphiphiles self-assemble via multiple H-bonding to form stable artificial Cl−-channels within lipid bilayers. The alignment of water/Cl− wires influences the conduction of ions, envisioned to diffuse along the hydrophilic pathways; at acidic pH, Cl−/H+ symport conducts along a partly protonated channel, while at basic pH, higher Cl−/OH− antiport translocate through a neutral channel configuration, which can be greatly activated by applying strong electric field. This voltage/pH regulated channel system represents an unexplored alternative for ion-pumping along artificial ion-channels, parallel to that of biology. 相似文献
104.
Dr. Toshiro Takao Dr. Yuta Takahashi Masataka Kai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(29):e202200327
A dicationic triruthenium complex containing a μ3-η3-C3 ring, [(Cp*Ru)3(μ3-η3-C3MeH2−)(μ3-CH)(μ-H)]2+ ( 1 a , Cp*=η5-C5Me5), reacted with ammonia to yield a μ-amido complex, [(Cp*Ru)3(μ3-η3-CHCMeCH) (μ3-CH)(μ-NH2)]2+ ( 5 ), via N−H bond scission. Subsequent treatment with base resulted in C−N bond formation to yield a μ3-η2:η2-1-azabutadien-4-yl complex, [(Cp*Ru)3(μ3-CH)(μ3-η2:η2-NH=CH−CMe=CH−)]+ ( 6 a ). The azaruthenacyclopentadiene skeleton was alternatively synthesized by the photolysis of mono-cationic complex [(Cp*Ru)3(μ3-η3-C3RH2−)(μ3-CH)]+ ( 2 a ; R=Me, 2 b ; R=H) in the presence of ammonia. The C3 ring skeleton was broken via the electron transfer to the π*(C−C) orbital in the C3 ring, and a transiently generated unsaturated μ3-allylic species can take up ammonia, resulting in N−H bond scission followed by C−N bond formation. 相似文献
105.
106.
Dr. Matthieu Jouffroy Dr. Jongrock Kong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(9):2217-2221
Nucleophilic radical additions at innately electrophilic C(sp2) centers are perfectly suited for the direct functionalization of heterocycles. Using bench stable and commercially available alkyl oxamate and oxamic acid derivatives in combination with photoredox catalysis, a direct carbamoylation of heterocycles yielding amide functionalized pharmacophores in a single step is reported. The reaction conditions reported are compatible with structurally complex heterocyclic substrates of pharmaceutical interest. Notably, derivatives containing functional groups incompatible with standard amidation reactions, such as carboxylic acids and unprotected amines, were found to be amenable to this reaction paradigm. 相似文献
107.
Da-Liang Zhu Qi Wu Prof. Hai-Yan Li Prof. Dr. Hong-Xi Li Prof. Dr. Jian-Ping Lang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(16):3484-3488
Diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (HEH) has been utilized as a visible-light photoredox catalyst for the cross coupling of arylhalides and arylsulfinates without transition metal, sacrificial agent, and mediator. This method is compatible with various functional groups and provides diaryl sulfones in good to high yields. Mechanistic studies indicate that this reaction undergoes the stepwise light irradiation of HE−, single electron transfer (SET) in donor–acceptor complex (DAC) from *HE− to arylhalide, trapping of aryl radical with sulfinate, and SET oxidation of sulfone radical anion by HE. to sulfone by the DAC method. 相似文献
108.
Dr. Joseph N. Capilato Stefan A. Harry Dr. Maxime A. Siegler Prof. Thomas Lectka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202103922
As appreciation for nonclassical hydrogen bonds has progressively increased, so have efforts to characterize these interesting interactions. Whereas several kinds of C−H hydrogen bonds have been well-studied, much less is known about the R3N+−C−H⋅⋅⋅X variety. Herein, we present crystallographic and spectroscopic evidence for the existence of these interactions, with special relevance to Selectfluor chemistry. Of particular note is the propensity for Lewis bases to engage in nonclassical hydrogen bonding over halogen bonding with the electrophilic F atom of Selectfluor. Further, the first examples of 1H NMR experiments detailing R3N+−C−H⋅⋅⋅X (X=O, N) hydrogen bonds are described. 相似文献
109.
Honghua Zhang Huihong Wang Yi Jiang Fei Cao Weiwei Gao Longqing Zhu Yuhang Yang Xiaodong Wang Yongqiang Wang Jinhong Chen Yiyue Feng Xuemei Deng Yingmei Lu Xiaoling Hu Xiangxiang Li Juan Zhang Tao Shi Prof. Zhen Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(72):17289-17317
Sulfur-containing scaffold, as a ubiquitous structural motif, has been frequently used in natural products, bioactive chemicals and pharmaceuticals, particularly C−S/N−S bonds are indispensable in many biological important compounds and pharmaceuticals. Development of mild and general methods for C−S/N−S bonds formation has great significance in modern research. Iodine and its derivatives have been recognized as inexpensive, environmentally benign and easy-handled catalysts or reagents to promote the construction of C−S/N−S bonds under mild reaction conditions, with good regioselectivities and broad substrate scope. Especially based on this, several new strategies, such as oxidation relay strategy, have been greatly developed and accelerated the advancement of this field. This review focuses on recent advances in iodine and its derivatives promoted hybridized C−S/N−S bonds formation. The features and mechanisms of corresponding reactions are summarized and the results of some cases are compared with those of previous reports. In addition, the future of this domain is discussed. 相似文献
110.
Yuqing Yang Ehsan Raee Prof. Tianbo Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(10):e202104332
A unique trend in the binding affinity between cationic metal−organic cages (MOCs) and external counteranions in aqueous media was observed. Similar to many macroions, two MOCs, sharing similar structures but carrying different number of charges, self-assembled into hollow spherical single-layered blackberry-type structures through counterion-mediated attraction. Dynamic and static light scattering and isothermal titration calorimetry measurements confirm the stronger interactions among less charged MOCs and counteranions than that of highly charged MOCs, leading to larger assembly sizes. DOSY NMR measurements suggest the significance of thick hydration shells of highly charged MOCs, inhibiting the MOC-counterion binding and weakening the interaction between them. This study demonstrates that the greater role played by hydration shell on ion-pair formation comparing with charge density of MOCs. 相似文献