5350-57-2Relevant articles and documents
Keto-salicylaldehyde azine: Asymmetric substituent effect on their optical properties via electron-donating group insertion
Tong, Jialin,Zhang, Kexin,Wang, Jing,Li, Hui,Zhou, Fan,Wang, Zhiming,Zhang, Xiaojuan,Tang, Ben Zhong
, p. 996 - 1001 (2020)
Organic fluorescent probes have attracted increasing attention owing to their high sensitivity and recognition ability, structurally adjustable flexibility and manifestation in the form of visualization. Salicylaldehyde azine (SAA) and its derivatives exhibit a great potential for practical applications, but the synthesis of SAA asymmetric compounds in low yields, serving multiple functions, is cumbersome. As an alternative building block, Keto-Salicylaldehyde Azine (KSA) was developed by our group for constructing various AIEgens via an excited state intramolecular proton transfer (ESIPT) process to detect some cellular organelles and specific metal ions. For illuminating the structure-property relationship of the two asymmetric sides in a KSA unit, DPAS was employed as a model and the N,N-diethyl group with electron-donating effects was introduced on its salicylaldehyde side (S-terminal) and diphenylketone side (K-terminal). Three new derivatives were obtained and showed different photophysical properties, particularly in AIE performance and metal ion responsiveness, implying that their intrinsic electronic structure can be easily affected by the asymmetric substitution effect. Therefore, this study is a meaningful and valuable reference for KSA modification on expanding fluorescent probes with various functions via the purposeful regulation of their chemical structure, by either modifying the K-terminal or the S-terminal.
Electrochemical Studies of Diazoalkanes: The Formation and Decomposition of Ph2C=N2(radical-anion) and Ph2C=N22-
Cheng, Spencer,Hawley, M. Dale
, p. 3799 - 3804 (1986)
Ph2C=N2 undergoes successive one-electron reductions in DMF-0.1 M (CH3)4NBF4 at subambient temperatures to give a relatively stable anion radical and an unstable dianion.In the absence of added proton donors, Ph2C=N22- undergoes rapid reaction to give an unobserved intermediate, believed to be Ph2CH-, that reacts with Ph2C=N2 to give Ph2CHN-N=CPh2(radical) (k = 5*104 M*s-1 at -37 deg C).Ph2C=N2(radical-anion) reacts under these conditions by abstraction of a hydrogen atom from a component of the solvent-electrolyte system (k = 0.4 s-1 at -23 deg C) to give Ph2C=NNH- as a longer lived intermediate.This species subsequently reacts with Ph2C=N2, giving first Ph2CHN-N=CPh2 and then the final product, Ph2C=NN=CPh2.The transformation of Ph2C=N2 into Ph2C=NN=CPh2 occurs by a chain process and is initiated by both Ph2C=NNH- and Ph2CHN-N=CPh2.Ph2C=NNH- and Ph2CHN-N=CPh2 are proposed to react with Ph2C=N2 by pathways that transfer hydride ion, either directly or indirectly, from the anion to the central carbon of Ph2C=N2.The final steps in the propagation cycle involve the loss of N2 from Ph2CHN2- and the subsequent coupling of Ph2CH- with Ph2C=N2 to regenerate Ph2CHN-N=CPh2.Ph2C=N2(radical-anion) and Ph2(C=N22- behave as ambient bases in the presence of Broensted acids which can effect their protonation and afford, depending upon whether the central carbon or the terminal nitrogen is protonated, Ph2CH2 or Ph2C=NNH2, respectively.The fraction of Ph2C=NNH2 formed increases with decreasing pKa of the proton donor.
POLYAROMATIC UREA DERIVATIVES AND THEIR USE IN THE TREATMENT OF MUSCLE DISEASES
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Page/Page column 125, (2021/01/29)
The current invention provides urea derivatives, in particular compounds having the core structure heteroaryl-NH-CO-NH-aryl-O- heteroaryl, for use in treating, ameliorating, delaying, curing and/ or preventing a disease or condition associated with muscle cells and/or satellite cells, such as Duchenne muscular dystrophy, Becker muscular dystrophy, cachexia or sarcopenia.
Photochemical Carbene Transfer Reactions of Aryl/Aryl Diazoalkanes—Experiment and Theory**
Jana, Sripati,Pei, Chao,Empel, Claire,Koenigs, Rene M.
supporting information, p. 13271 - 13279 (2021/05/10)
Controlling the reactivity of carbene intermediates is a key parameter in the development of selective carbene transfer reactions and is usually achieved by metal complexes via singlet metal-carbene intermediates. In this combined experimental and computational studies, we show that the reactivity of free diaryl carbenes can be controlled by the electronic properties of the substituents without the need of external additives. The introduction of electron-donating and -withdrawing groups results in a significant perturbation of singlet triplet energy splitting of the diaryl carbene intermediate and of activation energies of consecutive carbene transfer reactions. This strategy now overcomes a long-standing paradigm in the reactivity of diaryl carbenes and allows the realization of highly chemoselective carbene transfer reactions with alkynes. We could show that free diaryl carbenes can be readily accessed via photolysis of the corresponding diazo compounds and that these carbenes can undergo highly chemoselective cyclopropenation, cascade, or C?H functionalization reactions. Experimental and theoretical mechanistic analyses confirm the participation of different carbene spin states and rationalize for the observed reactivity.
