scholarly journals Ozone-Mediated Amine Oxidation and Beyond: A Solvent Free, Flow-Chemistry Approach

2021 ◽  
Author(s):  
Eric Skrotzki ◽  
Jaya Kishore Vandavasi ◽  
Stephen Newman
Keyword(s):  
Organic Molecules ◽  
Flow Chemistry ◽  
Packed Bed ◽  
High Reactivity ◽  
Solvent Free ◽  
Packed Bed Reactor ◽  
Primary Amines ◽  
Amine Oxidation ◽  
Synthetic Utility ◽  
Free Oxidation

Ozone is a powerful oxidant, most commonly used for oxidation of alkenes to carbonyls. The synthetic utility of other ozone-mediated reactions is hindered by its high reactivity and propensity to over-oxidize organic molecules, including most solvents. This challenge can largely be mitigated by adsorbing both substrate and ozone onto silica gel, providing a solvent-free oxidation method. In this manuscript, a flow-based packed bed reactor approach is described that provides exceptional control of reaction temperature and time of this reaction to achieve improved control and chemoselectivity over this challenging reaction. A powerful method to oxidize primary amines into nitroalkanes is achieved. Examples of pyridine, C–H bond, and arene oxidations are also demonstrated, confirming the system is generalizable to diverse ozone-mediated processes.<br>

scholarly journals Ozone-Mediated Amine Oxidation and Beyond: A Solvent Free, Flow-Chemistry Approach

2021 ◽  
Author(s):  
Eric Skrotzki ◽  
Jaya Kishore Vandavasi ◽  
Stephen Newman
Keyword(s):  
Organic Molecules ◽  
Flow Chemistry ◽  
Packed Bed ◽  
High Reactivity ◽  
Solvent Free ◽  
Packed Bed Reactor ◽  
Primary Amines ◽  
Amine Oxidation ◽  
Synthetic Utility ◽  
Free Oxidation

Ozone is a powerful oxidant, most commonly used for oxidation of alkenes to carbonyls. The synthetic utility of other ozone-mediated reactions is hindered by its high reactivity and propensity to over-oxidize organic molecules, including most solvents. This challenge can largely be mitigated by adsorbing both substrate and ozone onto silica gel, providing a solvent-free oxidation method. In this manuscript, a flow-based packed bed reactor approach is described that provides exceptional control of reaction temperature and time of this reaction to achieve improved control and chemoselectivity over this challenging reaction. A powerful method to oxidize primary amines into nitroalkanes is achieved. Examples of pyridine, C–H bond, and arene oxidations are also demonstrated, confirming the system is generalizable to diverse ozone-mediated processes.<br>

Solvent-free methanolysis of canola oil in a packed-bed reactor with use of Novozym 435 plus loofa

2009 ◽  
Vol 45 (3) ◽  
pp. 188-194 ◽  
Author(s):  
M. Hajar ◽  
S. Shokrollahzadeh ◽  
F. Vahabzadeh ◽  
A. Monazzami
Keyword(s):  
Canola Oil ◽  
Packed Bed ◽  
Solvent Free ◽  
Packed Bed Reactor ◽  
Novozym 435

scholarly journals Stereoselective organocatalysis and flow chemistry

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Alessandra Puglisi ◽  
Sergio Rossi
Keyword(s):  
Continuous Flow ◽  
Organic Molecules ◽  
Flow Chemistry ◽  
Packed Bed ◽  
Enabling Technology ◽  
Catalytic Reactors ◽  
Continuous Flow Chemistry ◽  
Different Types ◽  
Stereoselective Reactions

AbstractOrganic synthesis has traditionally been performed in batch. Continuous-flow chemistry was recently rediscovered as an enabling technology to be applied to the synthesis of organic molecules. Organocatalysis is a well-established methodology, especially for the preparation of enantioenriched compounds. In this chapter we discuss the use of chiral organocatalysts in continuous flow. After the classification of the different types of catalytic reactors, in Section 2, each class will be discussed with the most recent and significant examples reported in the literature. In Section 3 we discuss homogeneous stereoselective reactions in flow, with a look at the stereoselective organophotoredox transformations in flow. This research topic is emerging as one of the most powerful method to prepare enantioenriched products with structures that would otherwise be challenging to make. Section 4 describes the use of supported organocatalysts in flow chemistry. Part of the discussion will be devoted to the choice of the support. Examples of packed-bed, monolithic and inner-wall functionalized reactors will be introduced and discussed. We hope to give an overview of the potentialities of the combination of (supported) chiral organocatalysts and flow chemistry.

scholarly journals Performance of an enzymatic packed bed reactor running on babassu oil to yield fatty ethyl esters (FAEE) in a solvent-free system

2015 ◽  
Vol 2 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Aline Simões ◽  
Lucas Ramos ◽  
Larissa Freitas ◽  
Julio C. Santos ◽  
Gisella M. Zanin ◽  
...  
Keyword(s):  
Packed Bed ◽  
Solvent Free ◽  
Ethyl Esters ◽  
Packed Bed Reactor ◽  
Free System ◽  
Babassu Oil ◽  
Solvent Free System

scholarly journals Continuous Production of 2-Phenylethyl Acetate in a Solvent-Free System Using a Packed-Bed Reactor with Novozym® 435

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 714 ◽  
Author(s):  
Shang-Ming Huang ◽  
Hsin-Yi Huang ◽  
Yu-Min Chen ◽  
Chia-Hung Kuo ◽  
Chwen-Jen Shieh
Keyword(s):  
Chemical Synthesis ◽  
Flow Rate ◽  
Packed Bed ◽  
Solvent Free ◽  
Packed Bed Reactor ◽  
Packed Bed Bioreactor ◽  
Free System ◽  
Phenethyl Alcohol ◽  
Solvent Free System ◽  
Molar Conversion

2-Phenylethyl acetate (2-PEAc), a highly valued natural volatile ester, with a rose-like odor, is widely added in cosmetics, soaps, foods, and drinks to strengthen scent or flavour. Nowadays, 2-PEAc are commonly produced by chemical synthesis or extraction. Alternatively, biocatalysis is a potential method to replace chemical synthesis or extraction for the production of natural flavour. Continuous synthesis of 2-PEAc in a solvent-free system using a packed bed bioreactor through immobilized lipase-catalyzed transesterification of ethyl acetate (EA) with 2-phenethyl alcohol was studied. A Box–Behnken experimental design with three-level-three-factor, including 2-phenethyl alcohol (2-PE) concentration (100–500 mM), flow rate (1–5 mL min−1) and reaction temperature (45–65 °C), was selected to investigate their influence on the molar conversion of 2-PEAc. Then, response surface methodology and ridge max analysis were used to discuss in detail the optimal reaction conditions for the synthesis of 2-PEAc. The results indicated both 2-PE concentration and flow rate are significant factors in the molar conversion of 2-PEAc. Based on the ridge max analysis, the maximum molar conversion was 99.01 ± 0.09% under optimal conditions at a 2-PE concentration of 62.07 mM, a flow rate of 2.75 mL min−1, and a temperature of 54.03 °C, respectively. The continuous packed bed bioreactor showed good stability for 2-PEAc production, enabling operation for at least 72 h without a significant decrease of conversion.

scholarly journals Improving Productivity of Multiphase Flow Aerobic Oxidation Using a Tube-in-Tube Membrane Contactor

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 95 ◽  
Author(s):  
Michael Burkholder ◽  
Stanley Gilliland ◽  
Adam Luxon ◽  
Christina Tang ◽  
B. Gupton
Keyword(s):  
Flow Reactor ◽  
Aerobic Oxidation ◽  
Flow Chemistry ◽  
Packed Bed ◽  
Space Time ◽  
Catalytic Reactions ◽  
Packed Bed Reactor ◽  
Membrane Contactor ◽  
Flow Reactors ◽  
Space Time Yield

The application of flow reactors in multiphase catalytic reactions represents a promising approach for enhancing the efficiency of this important class of chemical reactions. We developed a simple approach to improve the reactor productivity of multiphase catalytic reactions performed using a flow chemistry unit with a packed bed reactor. Specifically, a tube-in-tube membrane contactor (sparger) integrated in-line with the flow reactor has been successfully applied to the aerobic oxidation of benzyl alcohol to benzaldehyde utilizing a heterogeneous palladium catalyst in the packed bed. We examined the effect of sparger hydrodynamics on reactor productivity quantified by space time yield (STY). Implementation of the sparger, versus segmented flow achieved with the built in gas dosing module (1) increased reactor productivity 4-fold quantified by space time yield while maintaining high selectivity and (2) improved process safety as demonstrated by lower effective operating pressures.

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