Benzoic acid resin (BAR): a heterogeneous redox organocatalyst for continuous flow synthesis of benzoquinones from β-O-4 lignin models

2021 ◽  
Vol 23 (6) ◽  
pp. 2308-2316
Author(s):  
Kevin de Aquino Dias ◽  
Marcus Vinicius Pinto Pereira Junior ◽  
Leandro Helgueira Andrade
Keyword(s):  
Benzoic Acid ◽  
Continuous Flow ◽  
Phenol Oxidation ◽  
Tandem Catalysis ◽  
One Pot ◽  
Flow Synthesis ◽  
Acid Resin

Benzoic acid resin (BAR), a redox organocatalyst for both Baeyer–Villiger and phenol oxidation, is described. BAR enabled the continuous-flow synthesis of benzoquinones from β-O-4 lignin models in a one-pot protocol via auto-tandem catalysis.

scholarly journals High Yielding Flow Synthesis of a Macrocyclic Molecular Hinge

2021 ◽  
Author(s):  
Christopher Jones ◽  
Laurence J. Kershaw Cook ◽  
David Marquez-Gamez ◽  
Konstantin V. Luzyanin ◽  
Jonathan Steed ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Continuous Flow ◽  
Kinetic Studies ◽  
Molecular Machines ◽  
High Dilution ◽  
Fluoride Ions ◽  
One Pot ◽  
Flow Synthesis ◽  
Single Isomer ◽  
Molecular Hinge

ABSTRACT: Many molecular machines are built from modular components with well-defined motile capabilities, such as axles and wheels. Hinges are particularly useful, as they provide the minimum flexibility needed for a simple and pronounced conformational change. Compounds with multiple stable conformers are common, but molecular hinges almost exclusively operate via dihedral rotations rather than truly hinge-like clamping mechanisms. An ideal molecular hinge would better reproduce the behavior of hinged devices, such as gates and tweezers, while remaining soluble, scalable and synthetically versatile. Herein, we describe two isomeric macrocycles with clamp-like open and closed geometries, which crystallize as separate polymorphs but interconvert freely in solution. An unusual one-pot addition cyclization reaction was used to produce the macrocycles on a multigram scale from inexpensive reagents, without supramolecular templating or high-dilution conditions. Using mechanistic information from NMR kinetic studies and at-line mass spectrometry, we developed a semi-continuous flow synthesis with maximum conversions of 85-93% and over 80% selectivity for a single isomer. The macrocycles feature voids that are sterically protected from guests, including reactive species such as fluoride ions, and could therefore serve as chemically inert hinges for adaptive supramolecular receptors and flexible porous materials.

scholarly journals A Scalable, Combined-Batch, and Continuous-Flow Synthesis of a Bio-Inspired UV-B Absorber

2019 ◽  
Vol 72 (11) ◽  
pp. 860 ◽  
Author(s):  
Mark York ◽  
Karen E. Jarvis ◽  
Jamie A. Freemont ◽  
John H. Ryan ◽  
G. Paul Savage ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Partial Reduction ◽  
One Pot ◽  
Flow Synthesis ◽  
Sample Throughput

A new, chromatography-free synthesis for the preparation of an experimental UV-B absorber is reported. A key step of the process is a one-pot partial reduction of a symmetrical imide with a sequential dehydration step. The synthesis uses several continuous-flow steps to increase sample throughput and was used to prepare sufficient material to support further testing activities in >99% purity.

Continuous flow synthesis of 2,2′-diselenobis(benzoic acid) and derivatives

2020 ◽  
Vol 5 (4) ◽  
pp. 641-644 ◽  
Author(s):  
Francesca Begini ◽  
Dorota Krasowska ◽  
Aleksandra Jasiak ◽  
Jozef Drabowicz ◽  
Claudio Santi ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Building Block ◽  
Continuous Flow ◽  
Flow Synthesis

The continuous flow synthesis of the key building block 2,2′-diselenobis(benzoic acid) (DSBA) and its analogues is herein reported.

scholarly journals High Yielding Flow Synthesis of a Macrocyclic Molecular Hinge

2021 ◽  
Author(s):  
Christopher Jones ◽  
Laurence J. Kershaw Cook ◽  
David Marquez-Gamez ◽  
Konstantin V. Luzyanin ◽  
Jonathan Steed ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Continuous Flow ◽  
Kinetic Studies ◽  
Molecular Machines ◽  
High Dilution ◽  
Fluoride Ions ◽  
One Pot ◽  
Flow Synthesis ◽  
Single Isomer ◽  
Molecular Hinge

ABSTRACT: Many molecular machines are built from modular components with well-defined motile capabilities, such as axles and wheels. Hinges are particularly useful, as they provide the minimum flexibility needed for a simple and pronounced conformational change. Compounds with multiple stable conformers are common, but molecular hinges almost exclusively operate via dihedral rotations rather than truly hinge-like clamping mechanisms. An ideal molecular hinge would better reproduce the behavior of hinged devices, such as gates and tweezers, while remaining soluble, scalable and synthetically versatile. Herein, we describe two isomeric macrocycles with clamp-like open and closed geometries, which crystallize as separate polymorphs but interconvert freely in solution. An unusual one-pot addition cyclization reaction was used to produce the macrocycles on a multigram scale from inexpensive reagents, without supramolecular templating or high-dilution conditions. Using mechanistic information from NMR kinetic studies and at-line mass spectrometry, we developed a semi-continuous flow synthesis with maximum conversions of 85-93% and over 80% selectivity for a single isomer. The macrocycles feature voids that are sterically protected from guests, including reactive species such as fluoride ions, and could therefore serve as chemically inert hinges for adaptive supramolecular receptors and flexible porous materials.

scholarly journals Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

2018 ◽  
Vol 14 ◽  
pp. 1917-1936 ◽  
Author(s):  
Mrityunjay K Sharma ◽  
Roopashri B Acharya ◽  
Chinmay A Shukla ◽  
Amol A Kulkarni
Keyword(s):  
Detailed Analysis ◽  
Continuous Flow ◽  
Next Generation ◽  
One Pot ◽  
Complex Molecules ◽  
Flow Synthesis ◽  
One Pot Synthesis ◽  
Wide Range ◽  
Line Separation

The multistep flow synthesis of complex molecules has gained momentum over the last few years. A wide range of reaction types and conditions have been integrated seamlessly on a single platform including in-line separation as well as monitoring. Beyond merely getting considered as ‘flow version’ of conventional ‘one-pot synthesis’, multistep flow synthesis has become the next generation tool for creating libraries of new molecules. Here we give a more ‘engineering’ look at the possibility of developing a ‘unified multistep flow synthesis platform’. A detailed analysis of various scenarios is presented considering 4 different classes of drugs already reported in the literature. The possible complexities that an automated and controlled platform needs to handle are also discussed in detail. Three different design approaches are proposed: (i) one molecule at a time, (ii) many molecules at a time and (iii) cybernetic approach. Each approach would lead to the effortless integration of different synthesis stages and also at different synthesis scales. While one may expect such a platform to operate like a ‘driverless car’ or a ‘robo chemist’ or a ‘transformer’, in reality, such an envisaged system would be much more complex than these examples.

Continuous flow synthesis of the lamivudine precursor L-Menthyl Glyoxylate

2021 ◽  
Author(s):  
Lais S. D. Azevedo ◽  
Anderson R. Aguillon ◽  
Marcelo T. Lima ◽  
Raquel A. C. Leão ◽  
Rodrigo O. M. A. de Souza
Keyword(s):  
Continuous Flow ◽  
Flow Synthesis

Both sites must turn over in tandem catalysis: Lessons from one-pot CO2 capture and hydrogenation

2021 ◽  
Author(s):  
Elizabeth A. K. Wilson ◽  
Shawn C. Eady ◽  
Trent Silbaugh ◽  
Levi T. Thompson ◽  
Mark A. Barteau
Keyword(s):  
Co2 Capture ◽  
Tandem Catalysis ◽  
One Pot ◽  
Turn Over

Continuous Flow Synthesis of Persistent Luminescent Chromium-Doped Zinc Gallate Nanoparticles

2021 ◽  
pp. 7067-7075
Author(s):  
Xiaojun Wei ◽  
Stephen V. Kershaw ◽  
Xiaodan Huang ◽  
Mingxia Jiao ◽  
Chau Chun Beh ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Synthesis ◽  
Zinc Gallate

scholarly journals Continuous flow synthesis of azoxybenzenes by reductive dimerization of nitrosobenzenes with gel‐bound catalysts

2021 ◽  
Author(s):  
Carsten J. Schmiegel ◽  
Patrik Berg ◽  
Franziska Obst ◽  
Roland Schoch ◽  
Dietmar Appelhans ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Synthesis ◽  
Reductive Dimerization
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