scholarly journals Electrophilic Bromination in Flow: A Safe and Sustainable Alternative to the Use of Molecular Bromine in Batch

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2116 ◽  
Author(s):  
Reinout Van Kerrebroeck ◽  
Pieter Naert ◽  
Thomas S. A. Heugebaert ◽  
Matthias D’hooghe ◽  
Christian V. Stevens
Keyword(s):  
Chemical Industry ◽  
Continuous Flow ◽  
Building Blocks ◽  
Molecular Bromine ◽  
Industrial Environment ◽  
Aromatic Substrates ◽  
Bromination Reaction ◽  
Electrophilic Bromination

Bromination reactions are crucial in today’s chemical industry since the versatility of the formed organobromides makes them suitable building blocks for numerous syntheses. However, the use of the toxic and highly reactive molecular bromine (Br2) makes these brominations very challenging and hazardous. We describe here a safe and straightforward protocol for bromination in continuous flow. The hazardous Br2 or KOBr is generated in situ by reacting an oxidant (NaOCl) with HBr or KBr, respectively, which is directly coupled to the bromination reaction and a quench of residual bromine. This protocol was demonstrated by polybrominating both alkenes and aromatic substrates in a wide variety of solvents, with yields ranging from 78% to 99%. The protocol can easily be adapted for the bromination of other substrates in an academic and industrial environment.

In Situ Preparation and Consumption of O-Mesitylsulfonylhydroxylamine (MSH) in Continuous Flow for the Amination of Pyridines

Synlett ◽  
2017 ◽  
Vol 28 (13) ◽  
pp. 1636-1640 ◽  
Author(s):  
Cara Brocklehurst ◽  
Guido Koch ◽  
Stephanie Rothe-Pöllet ◽  
Luigi La Vecchia
Keyword(s):  
Continuous Flow ◽  
Building Blocks ◽  
Safe Method ◽  
In Situ Preparation

The paper demonstrates a safe method in which highly unstable O-mesitylsulfonylhydroxylamine (MSH) can be prepared and consumed in continuous flow. MSH was prepared in situ and used for the flow amination of a range of pyridines, which were subsequently transformed into useful pyrazolopyridine building blocks.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Functional response of Fucus vesiculosus communities to tributyltin measured in an in situ continuous flow-through system

Hydrobiologia ◽  
1989 ◽  
Vol 188-189 (1) ◽  
pp. 277-283 ◽  
Author(s):  
C. Lindblad ◽  
U. Kautsky ◽  
C. André ◽  
N. Kautsky ◽  
M. Tedengren
Keyword(s):  
Functional Response ◽  
Continuous Flow ◽  
Fucus Vesiculosus ◽  
Flow Through

scholarly journals Exploring Cu/Al cluster growth and reactivity: from embryonic building blocks to intermetalloid, open-shell superatoms

2021 ◽  
Author(s):  
Max Schütz ◽  
Christian Gemel ◽  
Maximilian Muhr ◽  
Christian Jandl ◽  
Samia Kahlal ◽  
...  
Keyword(s):  
Closed Shell ◽  
Building Blocks ◽  
Open Shell ◽  
Cluster Growth ◽  
Powerful Technique

Cu/Al cluster growth reactions leading to open- and closed-shell superatoms are investigated. Therein, LIFDI-MS is presented as a powerful technique for the in situ detection of cluster identities and reactivity patterns.

scholarly journals Nanofiltration-Enabled In Situ Solvent and Reagent Recycle for Sustainable Continuous-Flow Synthesis

ChemSusChem ◽  
2017 ◽  
Vol 10 (17) ◽  
pp. 3435-3444 ◽  
Author(s):  
Tamas Fodi ◽  
Christos Didaskalou ◽  
Jozsef Kupai ◽  
Gyorgy T. Balogh ◽  
Peter Huszthy ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Synthesis

Sustainable Aldehyde Oxidations in Continuous Flow Using in Situ-Generated Performic Acid

2021 ◽  
Vol 9 (16) ◽  
pp. 5519-5525
Author(s):  
Michael Prieschl ◽  
Sándor B. Ötvös ◽  
C. Oliver Kappe
Keyword(s):  
Continuous Flow ◽  
Performic Acid
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