- Activated Self-Resolution and Error-Correction in Catalytic Reaction Networks**
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Understanding the emergence of function in complex reaction networks is a primary goal of systems chemistry and origin-of-life studies. Especially challenging is to create systems that simultaneously exhibit several emergent functions that can be independently tuned. In this work, a multifunctional complex reaction network of nucleophilic small molecule catalysts for the Morita-Baylis-Hillman (MBH) reaction is demonstrated. The dynamic system exhibited triggered self-resolution, preferentially amplifying a specific catalyst/product set out of a many potential alternatives. By utilizing selective reversibility of the products of the reaction set, systemic thermodynamically driven error-correction could also be introduced. To achieve this, a dynamic covalent MBH reaction based on adducts with internal H-transfer capabilities was developed. By careful tuning of the substituents, rate accelerations of retro-MBH reactions of up to four orders of magnitude could be obtained. This study thus demonstrates how efficient self-sorting of catalytic systems can be achieved through an interplay of several complex emergent functionalities.
- Schaufelberger, Fredrik,Ramstr?m, Olof
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p. 10335 - 10340
(2021/05/07)
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- Preparation method of ambroxol hydrochloride
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The invention relates to a preparation method of ambroxol hydrochloride, and the method comprises the following steps: carrying out aldehyde group protection on o-nitrobenzaldehyde, and reducing hydrazine hydrate in the presence of a catalyst NiCoB/TiO2 to obtain a compound 3; carrying out bromination reaction on the compound 3 under the action of molecular bromine and hydrogen peroxide, and carrying out deprotection to generate a compound 2; and carrying out aldehyde reductive amination reaction with trans-4-aminocyclohexanol under the action of catalysts NaBH (OAc) 3 and LiClO4, and salifying to obtain the ambroxol hydrochloride. The method has the advantages of mild conditions, simple steps, environmental friendliness, easily stored raw materials and high yield, and is suitable for industrial production.
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- Synthesis and selective 2H-, 13C-, and 15N-labeling of the Tau protein binder THK-523
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A new synthetic route to the Tau binder, THK-523, is disclosed herein, which can easily be adapted to 13C- and D-isotope labeling. The synthesis proceeds via two key reactions, namely, a Pd-catalyzed carbonylative Sonogashira coupling and a red
- Neumann, Karoline T.,Lindhardt, Anders T.,Bang-Andersen, Benny,Skrydstrup, Troels
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- Chiroptical Asymmetric Reaction Screening via Multicomponent Self-Assembly
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Self-assembly of a stereodynamic phosphine ligand, Pd(II), and a chiral amine, amino alcohol, or amino acid generates characteristic UV and CD signals that can be used for quantitative stereochemical analysis of the bound substrate. A robust mix-and-measure chiroptical sensing protocol has been developed and used to determine the absolute configuration, ee, and yield of an amine produced by Ir-catalyzed asymmetric hydrogenation of an iminium salt. The analysis requires only 1 mg of the crude reaction mixture and minimizes cost, labor, time, and waste.
- De Los Santos, Zeus A.,Wolf, Christian
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p. 13517 - 13520
(2016/10/31)
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- Photoassisted diversity-oriented synthesis: Intramolecular cycloadditions of photogenerated azaxylylenes with oxazole pendants, and subsequent postphotochemical multicomponent modifications
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Photogenerated aza-o-xylylenes undergo intramolecular cycloaddition reactions to tethered oxazoles, with primary photoproducts featuring a reactive cyclic imine moiety suitable for multicomponent postphotochemical transformations. For example, the reactio
- Kumar, N. N. Bhuvan,Kutateladze, Andrei G.
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supporting information
p. 460 - 463
(2016/02/18)
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- Intramolecular cycloadditions of photogenerated azaxylylenes with oxadiazoles provide direct access to versatile polyheterocyclic ketopiperazines containing a spiro-oxirane moiety
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Photogenerated azaxylylenes undergo intramolecular cycloadditions to 1,3,4-oxadiazole pendants, which are accompanied by concomitant release of dinitrogen, yielding functionalized ketopiperazinoquinolinols containing an oxirane moiety fused to the quinolinole moiety while spiro-connected to diketopiperazine. These primary photoproducts are reactive versatile intermediates which can be further derivatized under nucleophilic SN1- or SN2-like ring opening of the oxirane moiety. The oxidized quinolinones undergo new rearrangements under the conditions of the Schmidt reaction, leading to unprecedented triazacanoindolinones.
- Kumar, N. N. Bhuvan,Kuznetsov, Dmitry M.,Kutateladze, Andrei G.
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supporting information
p. 438 - 441
(2015/03/03)
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- Photoassisted synthesis of enantiopure alkaloid mimics possessing unprecedented polyheterocyclic cores
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Enantiopure alkaloid mimics are synthesized via high yielding intramolecular cycloadditions of photogenerated azaxylylenes tethered to pyrroles, with further growth of molecular complexity via post-photochemical transformations of primary photoproducts. This expeditious access to structurally unprecedented polyheterocyclic cores is being developed in the context of diversity-oriented synthesis, as the modular design allows for rapid "pre-assembly" of diverse photoprecursors from simple building blocks/diversity inputs.
- Kumar, N.N. Bhuvan,Mukhina, Olga A.,Kutateladze, Andrei G.
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supporting information
p. 9608 - 9611
(2013/07/26)
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- Rapid photoassisted access to N,O,S-polyheterocycles with benzoazocine and hydroquinoline cores: Intramolecular cycloadditions of photogenerated azaxylylenes
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Ring the changes: A new photoassisted approach to give conformationally constrained N,O,S-polyheterocyclic scaffolds of unprecedented topologies was achieved by intramolecular [4+4] and [4+2] cycloadditions of photogenerated o-azaxylylenes (23 examples; see scheme). The precursors can be readily assembled by simple and high-yielding reactions, thus making this a powerful synthetic method amenable to high-throughput diversity-oriented synthesis.
- Mukhina, Olga A.,Bhuvan Kumar,Arisco, Teresa M.,Valiulin, Roman A.,Metzel, Greg A.,Kutateladze, Andrei G.
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supporting information; experimental part
p. 9423 - 9428
(2011/11/06)
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- Relaying stereochemistry through aromatic ureas: 1,9 and 1,15 remote stereocontrol
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The well-defined conformation of an N,N′-diarylurea allows a chiral sulfinyl substituent to influence diastereoselectivity in the formation of new stereogenic centres up to 14 bond lengths away. The Royal Society of Chemistry.
- Clayden, Jonathan,Pickworth, Mark,Jones, Lyn H.
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supporting information; experimental part
p. 547 - 549
(2009/06/17)
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- Design and synthesis of novel N-benzylidenesulfonohydrazide inhibitors of murC and murD as potential antibacterial agents
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A series of novel N-benzylidenesulfonohydrazide compounds were designed and synthesized as inhibitors of UDP-N-acetylmuramic acid:L-alanine ligase (MurC) and UDP-N-acetylmuramoyl-L-alanine:D-glutamate ligase (MurD) from E. coli, involved in the biosynthes
- Frlan, Rok,Kovac, Andreja,Blanot, Didier,Gobec, Stanislav,Pecar, Slavko,Obreza, Ales
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- New arylsulfonohydrazide inhibitors of enzymes MurC and MurD
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This invention belongs to the field of pharmaceutical chemistry and relates to new arylsulfonohydrazides as inhibitors of UDP-N-acetylmuramyl:L-alanine ligaze (MurC) and UDP-N-acetylmuramyl-L-alanine:D-glutamate ligaze (MurD), to procedures for their preparation and pharmaceutical preparations containing the same. The enzymes MurC and MurD are the key enzymes involved in the synthesis of bacterial peptidoglycan, so arylsulfonohydrazide inhibitors possess antibacterial activity. Compounds of general formula I and the pharmaceutically acceptable salts are described. The appropriate substituents are clearly presented in the body of the text and in claims.
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Page/Page column 27
(2008/06/13)
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