Highly Enantioselective Immobilized Prolinamide-Catalyzed Aldol Reactions in Continuous-Flow Systems: Effect of Water on Catalyst Lifetime and Application to the Synthesis of a Chiral Fenpentadiol Analogue

2021 ◽  
Author(s):  
Caizhen Yue ◽  
Yasuhiro Yamashita ◽  
Shu Kobayashi
Keyword(s):  
Continuous Flow ◽  
Flow System ◽  
Aldol Reactions ◽  
Flow Conditions ◽  
Effect Of Water ◽  
Flow Systems ◽  
First Time ◽  
Catalyst Lifetime

Catalytic enantioselective aldol reactions of trifluoroacetophenones with ketones under continuous-flow conditions have been developed for the first time by using polystyrene-supported prolinamides. The robustness of the flow system was demonstrated...

Reversal of the enantioselectivity in aldol addition over immobilized di- and tripeptides: studies under continuous flow conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (106) ◽  
pp. 61611-61618 ◽  
Author(s):  
András Gurka ◽  
Imre Bucsi ◽  
Lenke Kovács ◽  
György Szőllősi ◽  
Mihály Bartók
Keyword(s):  
Continuous Flow ◽  
Flow System ◽  
Aldol Reactions ◽  
Flow Conditions ◽  
Continuous Flow System ◽  
System P ◽  
Aldol Addition

The reversal of the enantioselectivity in the heterogeneous asymmetric direct aldol reactions obtained over resin supported di- versus tripeptides was studied in a continuous-flow system.

scholarly journals Cultivation of a cellulolytic microbial community under continuous flow conditions

2021 ◽  
Author(s):  
David Jenkins
Keyword(s):  
Flow Rate ◽  
Continuous Flow ◽  
Microbial Consortium ◽  
Flow System ◽  
Cellulose Degradation ◽  
Cellulose Hydrolysis ◽  
Flow Conditions ◽  
Continuous Flow System ◽  
Enrichment Process ◽  
High Ethanol

A stable microbial consortium capable of cellulose hydrolysis under initial aerobic conditions has been enriched in a continuous flow system. Anaerobic conditions were created and maintained within the flow system using only microbial metabolism. A DGGE community profile of samples taken throughout the enrichment process indicates that the community stabilized upon entry into the continuous flow system, and maintained function and members throughout. The effect of flow rate on cellulose degradation and end product production was assessed. The cellulose degradation rate was found to be notably faster at a flow rate of 0.1 ml/min (D 0.75/hr) than a flow rate of 0.2 ml/min (D1.50/hr). Furthermore, an ethanol to acetate ratio nearly 8 times higher than previously reported values in the literature was also observed at 0.1 ml/min (D0.75/hr). With reduced flow rate and high ethanol to acetate ratios, the enriched community may be well suited for consolidate bioprocessing.

Karst evolution, hydrocarbon and geothermal resources in flow system context (South Hungary)

2021 ◽  
Author(s):  
Katalin Csondor ◽  
Lehel Csobaji ◽  
Brigitta Zentai-Czauner ◽  
Orsolya Győri ◽  
Anita Erőss
Keyword(s):  
Fluid Flow ◽  
Flow System ◽  
Water Discharge ◽  
Regional Scale ◽  
Local Scale ◽  
Karst Area ◽  
Flow Conditions ◽  
Regional Flow ◽  
Basin Scale ◽  
Flow Systems

<p>In South Transdanubia (Hungary) there are remarkable geothermal and hydrocarbon resources. The area is also characterized by natural thermal water discharge at the boundary of outcropping carbonate hills and adjacent sedimentary basin. These regional discharge areas are favourable sites of hypogenic caves as well. These geofluid systems and groundwater related phenomena are usually investigated separately and their interactions are just neglected. The aim of this study is to give all these groundwater-related resources and phenomena a common framework applying the concept of regional hydraulic continuity, and to complete the basin-scale hydraulic assessment of the area based on preproduction archival measured data. Pressure-elevation profiles, tomographic fluid-potential maps and hydraulic cross-sections were constructed to determine the vertical and horizontal fluid-flow conditions. As a result, two kinds of fluid flow systems could be identified. Within the gravitational flow systems, horizontal flow conditions are dominant and the regional flow direction tends toward the S–SE. In deeper basin regions, an overpressured flow system is prevalent, where fluids are driven laterally from the deeper sub-basins towards their margins. Based on the regional-scale evaluation of fluid flow systems, conclusions could be drawn regarding the geothermal and hydrocarbon potential of the area. Additionally, local-scale phenomena could be explained, and the study emphasizes that knowledge on regional groundwater flow systems is essential to understand local scale groundwater-related phenomena such as recent cave formation in an area. A comparison with the marginal Buda Thermal Karst area allows for generalized conclusions regarding the connections between marginal karst reservoirs and the Pannonian Basin. Furthermore, the results of the study can be directly applied in the exploration and sustainable utilization of groundwater related resources, such as thermal waters and hydrocarbons.</p><p>This topic is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 810980. The National Research, Development and Innovation Fund has provided financial support to the research under the grant agreement no. PD 116227.</p>

scholarly journals Metal-porphyrin catalyzed aziridination of α-methylstyrene: Batch vs. flow process

2017 ◽  
Vol 21 (04-06) ◽  
pp. 381-390 ◽  
Author(s):  
Daniela Intrieri ◽  
Sergio Rossi ◽  
Alessandra Puglisi ◽  
Emma Gallo
Keyword(s):  
Dft Calculations ◽  
Continuous Flow ◽  
Flow System ◽  
Reaction Times ◽  
Batch Process ◽  
Porphyrin Ring ◽  
Flow Conditions ◽  
Metal Porphyrin ◽  
Flow Process ◽  
Influence Of Substituents

This work describes the aziridination process of [Formula: see text]-methylstyrene by using electron poor aromatic azides in the presence of metal-based porphyrins as catalysts. Different ruthenium and cobalt-based porphyrins were successfully employed for the synthesis of [Formula: see text]-aryl aziridines performed under a traditional batch methodology and under continuous flow conditions. In general, yields obtained using ruthenium-based catalysts in a traditional batch process were higher than those observed when the reaction was performed under flow conditions. However, cobalt-based porphyrins showed better activities and short reaction times when employed in a flow system process. DFT calculations were also performed in order to understand the influence of substituents on the porphyrin ring in the aziridination process.

scholarly journals Cultivation of a cellulolytic microbial community under continuous flow conditions

2021 ◽  
Author(s):  
David Jenkins
Keyword(s):  
Flow Rate ◽  
Continuous Flow ◽  
Microbial Consortium ◽  
Flow System ◽  
Cellulose Degradation ◽  
Cellulose Hydrolysis ◽  
Flow Conditions ◽  
Continuous Flow System ◽  
Enrichment Process ◽  
High Ethanol

A stable microbial consortium capable of cellulose hydrolysis under initial aerobic conditions has been enriched in a continuous flow system. Anaerobic conditions were created and maintained within the flow system using only microbial metabolism. A DGGE community profile of samples taken throughout the enrichment process indicates that the community stabilized upon entry into the continuous flow system, and maintained function and members throughout. The effect of flow rate on cellulose degradation and end product production was assessed. The cellulose degradation rate was found to be notably faster at a flow rate of 0.1 ml/min (D 0.75/hr) than a flow rate of 0.2 ml/min (D1.50/hr). Furthermore, an ethanol to acetate ratio nearly 8 times higher than previously reported values in the literature was also observed at 0.1 ml/min (D0.75/hr). With reduced flow rate and high ethanol to acetate ratios, the enriched community may be well suited for consolidate bioprocessing.

scholarly journals Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

2016 ◽  
Vol 12 ◽  
pp. 2614-2619 ◽  
Author(s):  
Riccardo Porta ◽  
Alessandra Puglisi ◽  
Giacomo Colombo ◽  
Sergio Rossi ◽  
Maurizio Benaglia
Keyword(s):  
Continuous Flow ◽  
Reaction Times ◽  
Nitro Compounds ◽  
Primary Amines ◽  
Flow Conditions ◽  
Metal Free ◽  
Nitro Derivatives ◽  
Aromatic Nitro ◽  
High Yields ◽  
First Time

The metal-free reduction of nitro compounds to amines mediated by trichlorosilane was successfully performed for the first time under continuous-flow conditions. Aromatic as well as aliphatic nitro derivatives were converted to the corresponding primary amines in high yields and very short reaction times with no need for purification. The methodology was also extended to the synthesis of two synthetically relevant intermediates (precursors of baclofen and boscalid).

scholarly journals A Novel, Domino Synthesis of Tricyclic Benzimidazole Derivatives Using Continuous Flow

2019 ◽  
Vol 64 (1) ◽  
pp. 1-8
Author(s):  
Balázs Szabó ◽  
Kiara Szakter ◽  
Angelika Thurner ◽  
Ferenc Faigl ◽  
János Éles ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Flow System ◽  
Flow Chemistry ◽  
Benzimidazole Derivatives ◽  
Flow Conditions ◽  
One Pot ◽  
Continuous Flow Reactor ◽  
Novel Method ◽  
The One

A novel method for synthesis of tricyclic benzimidazole derivatives by using continuous flow reactor is reported. Disadvantages of the well-known batch methods have been avoided utilizing the flow chemistry technology. Beside the one pot reductive cyclization using H-Cube Pro®, the dehydration step was also optimized producing the desired lactam compounds. Then the acylation was optimized under microwave conditions and that reaction was also integrated into the flow system using an Asia heater module. This acylation dramatically reduced the reaction time under continuous-flow conditions, with a residence time of 30 min.

scholarly journals Synthesis in mesoreactors: Ru(porphyrin)CO-catalyzed aziridination of olefins under continuous flow conditions

2016 ◽  
Vol 6 (13) ◽  
pp. 4700-4704 ◽  
Author(s):  
S. Rossi ◽  
A. Puglisi ◽  
M. Benaglia ◽  
D. M. Carminati ◽  
D. Intrieri ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Conditions ◽  
Aryl Azides ◽  
First Time

The Ru(porphyrin)CO-catalyzed addition of aryl azides to styrenes to afford N-aryl aziridines was successfully performed for the first time in mesoreactors under continuous flow conditions.

Nitrification and Autotrophic Denitrification in Calcium Alginate Beads

1987 ◽  
Vol 19 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Z. Lewandowski ◽  
R. Bakke ◽  
W. G. Characklis
Keyword(s):  
Calcium Carbonate ◽  
Calcium Ions ◽  
Continuous Flow ◽  
Calcium Alginate ◽  
Microbial Respiration ◽  
Flow System ◽  
Alginate Beads ◽  
Alginate Gel ◽  
Gel Beads ◽  
Calcium Alginate Gel

Immobilization of nitrifiers and autotrophic denitrifiers (Thiobacillus denitrificans) within calcium alginate gel was demonstrated. Calcium carbonate reagent was immobilized along with bacteria as the stabilizing agent. Protons released as a result of microbial respiration reacted with calcium carbonate producing calcium ions which internally stabilized the calcium alginate gel. The microbially active gel beads were mechanically stable and active for three months in a continuous flow system without addition of calcium.

Groundwater flow systems analysis on a regional and nation-wide scale in the Netherlands; the use of flow systems analysis in wetland management

1995 ◽  
Vol 31 (8) ◽  
pp. 375-378 ◽  
Author(s):  
F. H. Kloosterman ◽  
R. J. Stuurman ◽  
R. van der Meijden
Keyword(s):  
The Netherlands ◽  
Groundwater Flow ◽  
Systems Analysis ◽  
System Analysis ◽  
Drainage Basin ◽  
Flow System ◽  
Wetland Management ◽  
Groundwater Flow Systems ◽  
Flow Systems ◽  
Strong Relation

The project “National Groundwater Flow System Analysis” in The Netherlands was initiated in 1991 and will last until 1995. Financed by three Dutch Ministries, the project aims at the mapping of the regional groundwater flow systems to support policy makers at national levels and water/nature resources management. Much emphasis is put on biotic aspects such as the relation between groundwater and patterns in vegetation. The results are used in a detailed flow system analysis of the eco-hydrological valuable drainage basin of the brooks Beerze and Reusel in the southern parts of the country. In this study vegetation patterns and hydrological situations were analyzed in present and in historical settings to unravel the changes in the last decades leading to severe deterioration of habitats and wetlands. Historical data on flora from the beginning of this century on the basis of km-grid cells show a strong relation with the historical exfiltration areas where deep alkaline groundwaters rich in calcium-carbonate emerged. Agriculture and man-made changes to the natural drainage systems have led to diminishing nature values. Combining a sound understanding of the groundwater flow systems and the changes in the last decades produced a number of practical and viable measures to restore historical wetland settings and to preserve existing ones.

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