67083-40-3Relevant academic research and scientific papers
Reversible Photoswitchable Inhibitors Generate Ultrasensitivity in Out-of-Equilibrium Enzymatic Reactions
Teders, Michael,Pogodaev, Aleksandr A.,Bojanov, Glenn,Huck, Wilhelm T. S.
supporting information, p. 5709 - 5716 (2021/05/07)
Ultrasensitivity is a ubiquitous emergent property of biochemical reaction networks. The design and construction of synthetic reaction networks exhibiting ultrasensitivity has been challenging, but would greatly expand the potential properties of life-like materials. Herein, we exploit a general and modular strategy to reversibly regulate the activity of enzymes using light and show how ultrasensitivity arises in simple out-of-equilibrium enzymatic systems upon incorporation of reversible photoswitchable inhibitors (PIs). Utilizing a chromophore/warhead strategy, PIs of the protease α-chymotrypsin were synthesized, which led to the discovery of inhibitors with large differences in inhibition constants (Ki) for the different photoisomers. A microfluidic flow setup was used to study enzymatic reactions under out-of-equilibrium conditions by continuous addition and removal of reagents. Upon irradiation of the continuously stirred tank reactor with different light pulse sequences, i.e., varying the pulse duration or frequency of UV and blue light irradiation, reversible switching between photoisomers resulted in ultrasensitive responses in enzymatic activity as well as frequency filtering of input signals. This general and modular strategy enables reversible and tunable control over the kinetic rates of individual enzyme-catalyzed reactions and makes a programmable linkage of enzymes to a wide range of network topologies feasible.
Rhodium-Catalyzed Reaction of Azobenzenes and Nitrosoarenes toward Phenazines
Xiao, Yan,Wu, Xiaopeng,Wang, Hepan,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
supporting information, p. 2565 - 2568 (2019/04/30)
A rhodium-catalyzed annulative reaction between azobenzenes and nitrosoarenes has been developed, leading to a series of phenazines in moderate to good yields. This procedure proceeds with sequential chelation-assisted addition of aryl C-H to nitrosoarenes and ring closure by electrophilic attack of azo group to aryl. During this transformation, the azo group served as not only a traceless directing group but also a building block in the final products.
Anion ligand promoted selective C-F bond reductive elimination enables C(sp2)-H fluorination
Mao, Yang-Jie,Luo, Gen,Hao, Hong-Yan,Xu, Zhen-Yuan,Lou, Shao-Jie,Xu, Dan-Qian
supporting information, p. 14458 - 14461 (2019/12/09)
A detailed mechanism study on the anion ligand promoted selective C-H bond fluorination is reported. The role of the anion ligand has been clarified by experimental evidence and DFT calculations. Moreover, the nitrate promoted C-F bond reductive elimination enabled a selective C-H bond fluorination of various symmetric and asymmetric azobenzenes to access diverse o-fluoroanilines.
Coupling of N -Nosylhydrazones with Nitrosoarenes: Transition-Metal-Free Approach to (Z)- N -Arylnitrones
Liu, Tingting,Liu, Zhaohong,Liu, Zhenhua,Hu, Donghua,Wang, Yeming
supporting information, p. 1728 - 1736 (2018/02/14)
An efficient and transition-metal-free protocol for the synthesis of (Z)- N -arylnitrones from the direct coupling of N -nosylhydrazones with nitrosoarenes under mild conditions is described. The protocol is compatible with a wide range of functional groups placed on both the reagents and provided the corresponding nitrones in good to excellent yields by simple recrystallization process. The use of these 1,3-dipoles for the synthesis of substituted indoles is elaborated for 2,3-diphenyl-1 H -indole.
Rh(III)-Catalyzed bilateral cyclization of aldehydes with nitrosos toward unsymmetrical acridines proceeding with C-H functionalization enabled by a transient directing group
Hu, Weiming,Zheng, Qingheng,Sun, Song,Cheng, Jiang
supporting information, p. 6263 - 6266 (2017/07/07)
A Rh(iii)-catalyzed bilateral cyclization was developed for the efficient construction of acridines proceeding with C-H functionalization whereby in situ formation and removal of an imino transient directing group in the presence of catalytic amount of BnNH2 are achieved. In this transformation, a sequential Rh(iii)-catalyzed C-H amination, cyclization, and aromatization process was involved.
Palladium-catalyzed annulation of 2-(aryldiazenyl) aniline with dimethyl sulfoxide to access N-aryl-1H-benzo[d]imidazol-1-amine
Wang, Hepan,Sun, Song,Cheng, Jiang
supporting information, p. 3875 - 3878 (2017/09/15)
A palladium-catalyzed annulation of 2-(aryldiazenyl) aniline and dimethyl sulfoxide was developed to access N-aryl-1H-benzo[d]imidazol-1-amine in moderate to good yields. Activated by 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO), DMSO served as a “[dbnd]CH[sbnd]” fragment during this procedure. It represents a facile pathway leading to benzimidazoles.
Attraction or Repulsion? London Dispersion Forces Control Azobenzene Switches
Schweighauser, Luca,Strauss, Marcel A.,Bellotto, Silvia,Wegner, Hermann A.
supporting information, p. 13436 - 13439 (2015/11/09)
Large substituents are commonly seen as entirely repulsive through steric hindrance. Such groups have additional attractive effects arising from weak London dispersion forces between the neutral atoms. Steric interactions are recognized to have a strong influence on isomerization processes, such as in azobenzene-based molecular switches. Textbooks indicate that steric hindrance destabilizes the Z isomers. Herein, we demonstrate that increasing the bulkiness of electronically equal substituents in the meta-position decreases the thermal reaction rates from the Z to the E isomers. DFT computations revealed that attractive dispersion forces essentially lower the energy of the Z isomers.
Facile synthesis of unsymmetrical acridines and phenazines by a Rh(III)-catalyzed amination/cyclization/aromatization cascade
Lian, Yajing,Hummel, Joshua R.,Bergman, Robert G.,Ellman, Jonathan A.
supporting information, p. 12548 - 12551 (2013/09/23)
We report formal [3 + 3] annulations of aromatic azides with aromatic imines and azobenzenes to give acridines and phenazines, respectively. These transformations proceed through a cascade process of Rh(III)-catalyzed amination followed by intramolecular electrophilic aromatic substitution and aromatization. Acridines can be directly prepared from aromatic aldehydes by in situ imine formation using catalytic benzylamine.
In situ generation of nitroso compounds from catalytic hydrogen peroxide oxidation of primary aromatic amines and their one-pot use in hetero-Diels-Alder reactions
Zhao, Dongbo,Johansson, Mikael,Baeckvall, Jan-E.
, p. 4431 - 4436 (2008/04/13)
A method for in situ generation of nitroso compounds from organoselenium-catalyzed oxidation of anilines by hydrogen peroxide was developed. The generated nitroso compounds were subsequently used in hetero-Diels-Alder reactions. A variety of oxazines were synthesized in reasonable to good yields by this one-pot procedure using primary aromatic amines with different substituents and various conjugated dienes. This strategy might facilitate the current methodologies for nitroso chemistry since no isolation or purification of the nitroso compounds is required. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
DIKETIMINATO CU(I) AND CO(I) CARBENE CATALYSTS, AND CYCLOPROPANATION METHODS USING THEM
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Page/Page column 50, (2008/06/13)
The present invention described herein employs employs Cu(I) complexes of an electron-rich, bidentate N,N-donor ligand (P-diketiminates) that react with both heteroatomcontaining a-substituted diazomethanes and ary1diazomethanes to yield a unique metal-carbene complex stabilized by two metal fragments that selectively reacts with alkenes. These examples are the first of isolable Cu-carbene complexes that react with alkenes to give cyclopropanes. Furthermore, electron-rich, bidentate N,N-donor ligands can be designed to impart stereo- and enantio-selectivity in the cyclopropanation of alkenes with diazoalkanes.
