scholarly journals Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

2016 ◽  
Vol 12 ◽  
pp. 2267-2273 ◽  
Author(s):  
Arne Klinkebiel ◽  
Ole Beyer ◽  
Barbara Malawko ◽  
Ulrich Lüning
Keyword(s):  
Nitro Group ◽  
Carboxylic Acids ◽  
Functional Groups ◽  
Acid Chloride ◽  
Methoxy Group ◽  
Suzuki Coupling ◽  
Tricarboxylic Acid

New triazine-based tricarboxylic acid linkers were prepared as elongated relatives of triazinetribenzoic acid (TATB). Additionally, functional groups (NO2, NH2, OMe, OH) were introduced for potential post-synthetic modification (PSM) of MOFs. Functionalized tris(4-bromoaryl)triazine “cores” (3a,3b) were obtained by unsymmetric trimerization mixing one equivalent of an acid chloride (OMe or NO2 substituted) with two equivalents of an unsubstituted nitrile. Triple Suzuki coupling of the cores 3 with suitable phenyl- and biphenylboronic acid derivatives provided elongated tricarboxylic acid linkers as carboxylic acids 17 and 20 or their esters 16 and 19. Reduction of the nitro group and cleavage of the methoxy group gave the respective amino and hydroxy-substituted triazine linkers.

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

Preparation of Functionalized Diorganomagnesium Reagents in Toluene via Bromine or Iodine/Magnesium-Exchange Reactions

Synthesis ◽  
2021 ◽  
Author(s):  
Alexandre Desaintjean ◽  
Fanny Danton ◽  
Paul Knochel
Keyword(s):  
Exchange Reaction ◽  
Nitro Group ◽  
General Formula ◽  
Functional Groups ◽  
Exchange Reactions ◽  
Acyl Chlorides ◽  
Aryl Iodides ◽  
Highly Sensitive ◽  
Wide Range ◽  
Magnesium Exchange

A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents were prepared in toluene within 10 to 120 min between −78 °C and 25 °C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2Mg (R = sBu, Mes). Highly sensitive functional groups, such as a triazene or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arenes and alkenes derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides.

scholarly journals Palladium(II)-Catalyzed C(sp3)–H Activation of N,O-Ketals towards a Method for the β-Functionalization of Ketones

Synlett ◽  
2019 ◽  
Vol 30 (04) ◽  
pp. 454-458 ◽  
Author(s):  
Danny Ho ◽  
Jonas Calleja ◽  
Matthew Gaunt
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Building Blocks ◽  
Activation Pathway ◽  
Bond Forming ◽  
Aliphatic Ketones ◽  
Palladium Catalyzed

A method for the formal β-functionalization of aliphatic ketones via a palladium-catalyzed sp3 C–H activation pathway is reported. An N,O-ketal directs an aliphatic C–H carbonylation to form γ-lactams which upon hydrolysis generate γ-keto carboxylic acids. This C–C bond-forming reaction is tolerant of a range of functional groups, enabling the synthesis of a range of synthetically important building blocks. Furthermore, the concepts underlying this transformation have also enabled the development of a related C–H alkenylation process to highly functionalised heterocycles.

Reductive Condensation of a Nitro Group with Carboxylic Acids Promoted by Phosphorus(III) Compounds: A Short Route to 5H-Dibenzo[b,e][1,4]diazepin-11(10H)-ones

Synthesis ◽  
2020 ◽  
Author(s):  
Zbigniew Wróbel ◽  
Michał Tryniszewski ◽  
Robert Bujok ◽  
Roman Gańczarczyk
Keyword(s):  
Nitro Group ◽  
Carboxylic Acids ◽  
Carboxyl Group ◽  
Short Route ◽  
Step Method ◽  
One Pot ◽  
Aryl Group ◽  
Intramolecular Condensation ◽  
Reductive Condensation

Tributyl- or triphenylphosphine promotes a one-pot, three-step method for the synthesis of differently substituted dibenzodiazepinones from N-aryl-2-nitroanilines. Pyridine analogues and the corresponding thiazepinones can also be formed using this method. The process involves deoxygenation of the nitro group, then formation of an iminophosphorane intermediate and its intramolecular condensation with a carboxyl group placed in the N-aryl group. The role of the carboxyl group in the formation of the iminophosphorane and the mode of cyclization are discussed.

scholarly journals New Stable Manganese(III) Chelates of Some Pyridine Carboxylic Acids

1981 ◽  
Vol 36 (10) ◽  
pp. 1270-1272 ◽  
Author(s):  
Saktiprosad Ghosh ◽  
Pranab K. Ray ◽  
Tapas K. Bandyopadhyay ◽  
Amal K. Deb
Keyword(s):  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Carboxylic Acids ◽  
Tricarboxylic Acid ◽  
Pyridine Carboxylic ◽  
Physicochemical Methods

Abstract The syntheses of three new and unusually stable Mn(III) complexes of pyridine-2-carboxylic acid, pyridine-2,6-dicarboxylic acid and pyridine-2,4,6-tricarboxylic acid and their characterisation by various standard physicochemical methods is reported

scholarly journals Recent Progress in Nitro-Promoted Direct Functionalization of Pyridones and Quinolones

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 673 ◽  
Author(s):  
Feiyue Hao ◽  
Nagatoshi Nishiwaki
Keyword(s):  
Nitro Group ◽  
Functional Groups ◽  
Recent Progress ◽  
Alder Reaction ◽  
Diels Alder ◽  
Organic Syntheses ◽  
Diels Alder Reaction ◽  
Direct Functionalization ◽  
Nucleophilic Reagents

Nitro group is one of the most important functional groups in organic syntheses because its strongly electron-withdrawing ability activates the scaffold, facilitating the reaction with nucleophilic reagents or the Diels–Alder reaction. In this review, recent progress in the nitro-promoted direct functionalization of pyridones and quinolones is highlighted to complement previous reviews.

scholarly journals A facile and viable approach to fabricate polyamide membranes functionalized with graphene oxide nanosheets

RSC Advances ◽  
2017 ◽  
Vol 7 (84) ◽  
pp. 53463-53471 ◽  
Author(s):  
Ruizhi Pang ◽  
Kaisong Zhang
Keyword(s):  
Graphene Oxide ◽  
Functional Groups ◽  
Acid Chloride ◽  
Primary Amine ◽  
Covalent Binding ◽  
Graphene Oxide Nanosheets ◽  
Ro Membrane ◽  
Viable Approach ◽  
Polyamide Membranes

The covalent binding of GO nanosheets to a PA RO membrane was successfully achieved by reacting the primary amine functional groups of aminated GO (AGO) nanosheets with the unreacted acid chloride groups of the nascent PA membrane.

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