scholarly journals Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

2011 ◽  
Vol 7 ◽  
pp. 1486-1493 ◽  
Author(s):  
Xacobe C Cambeiro ◽  
Rafael Martín-Rapún ◽  
Pedro O Miranda ◽  
Sonia Sayalero ◽  
Esther Alza ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Optical Purity ◽  
Batch Process ◽  
Packed Bed ◽  
Catalyst Loading ◽  
Residence Times ◽  
Packed Bed Reactors ◽  
Effective Catalyst ◽  
Fold Reduction

The application of polystyrene-immobilized proline-based catalysts in packed-bed reactors for the continuous-flow, direct, enantioselective α-aminoxylation of aldehydes is described. The system allows the easy preparation of a series of β-aminoxy alcohols (after a reductive workup) with excellent optical purity and with an effective catalyst loading of ca. 2.5% (four-fold reduction compared to the batch process) working at residence times of ca. 5 min.

Designing continuous flow reaction of xylan hydrolysis for xylooligosaccharides production in packed-bed reactors using xylanase immobilized on methacrylic polymer-based supports

2018 ◽  
Vol 266 ◽  
pp. 249-258 ◽  
Author(s):  
Maria Romero-Fernández ◽  
Sonia Moreno-Perez ◽  
Alejandro H. Orrego ◽  
Sandro Martins de Oliveira ◽  
Ramón I. Santamaría ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Packed Bed ◽  
Packed Bed Reactors ◽  
Xylan Hydrolysis ◽  
Flow Reaction

Packed-Bed Reactors for Continuous-Flow CN Cross-Coupling

2010 ◽  
Vol 49 (49) ◽  
pp. 9469-9474 ◽  
Author(s):  
John R. Naber ◽  
Stephen L. Buchwald
Keyword(s):  
Continuous Flow ◽  
Cross Coupling ◽  
Packed Bed ◽  
Packed Bed Reactors

Studying the Morita-Baylis-Hillman Reaction in Continuous Flow Using Packed Bed Reactors

2018 ◽  
Vol 22 (11) ◽  
pp. 1524-1533
Author(s):  
Rasmus A. T. Verdier ◽  
Jesper H. Mikkelsen ◽  
Anders T. Lindhardt
Keyword(s):  
Continuous Flow ◽  
Packed Bed ◽  
Packed Bed Reactors

Packed-Bed Reactors for Continuous-Flow CN Cross-Coupling

2010 ◽  
Vol 122 (49) ◽  
pp. 9659-9664 ◽  
Author(s):  
John R. Naber ◽  
Stephen L. Buchwald
Keyword(s):  
Continuous Flow ◽  
Cross Coupling ◽  
Packed Bed ◽  
Packed Bed Reactors

scholarly journals Bismuth Subnitrate-Catalyzed Markovnikov-Type Alkyne Hydrations under Batch and Continuous Flow Conditions

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2864
Author(s):  
Zsanett Szécsényi ◽  
Ferenc Fülöp ◽  
Sándor B. Ötvös
Keyword(s):  
Continuous Flow ◽  
Reaction Medium ◽  
Batch Process ◽  
Packed Bed ◽  
Methyl Ketones ◽  
Flow Conditions ◽  
Efficient Catalyst ◽  
Ready Availability ◽  
Bismuth Subnitrate ◽  
Terminal Acetylenes

Bismuth subnitrate is reported herein as a simple and efficient catalyst for the atom-economical synthesis of methyl ketones via Markovnikov-type alkyne hydration. Besides an effective batch process under reasonably mild conditions, a chemically intensified continuous flow protocol was also developed in a packed-bed system. The applicability of the methodologies was demonstrated through hydration of a diverse set of terminal acetylenes. By simply switching the reaction medium from methanol to methanol-d4, valuable trideuteromethyl ketones were also prepared. Due to the ready availability and nontoxicity of the heterogeneous catalyst, which eliminated the need for any special additives and/or harmful reagents, the presented processes display significant advances in terms of practicality and sustainability.

Smoothing of stationary random signal in continuous flow mixer with gamma-distribution of residence times

1985 ◽  
Vol 50 (11) ◽  
pp. 2545-2557
Author(s):  
Pavel Hasal ◽  
Vladimír Kudrna ◽  
Jitka Vyhlídková
Keyword(s):  
Theoretical Analysis ◽  
Gamma Distribution ◽  
Continuous Flow ◽  
Random Signal ◽  
Linear Filter ◽  
Residence Times ◽  
Statistical Parameters ◽  
Basic Parameters

The paper is focused on a theoretical analysis of the function of continuous flow mixer with the so-called gamma-distribution of fluid residence times, used as a linear filter smoothing undesirable fluctuations of input properties. A relation is derived expressing the degree of smoothing of the signal passing through the system, as a function of statistical parameters of this signal and of gamma-distribution of fluid-residence times in the mixer. The analysis of this relation leads to conclusions concerning the prediction of the operation of smoothing mixers or the design of their basic parameters.

Design of a continuous flow immobilized-cell reactor for biosynthetical production of L-aspartic acid

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová
Keyword(s):  
Aspartic Acid ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Scale Up ◽  
Fixed Bed ◽  
Packed Bed ◽  
Fixed Bed Reactor ◽  
Experimental Program ◽  
Design Parameters ◽  
Immobilized Cell

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.

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