The Birch reduction is a reaction where aromatic compounds undergo partial reduction to unconjugated cyclohexadiene compounds in the presence of alkali metals like sodium or lithium in liquid ammonia. The solvated electrons from the reaction of the metal with liquid ammonia give the solution an intense blue color. The mechanism begins with single electron transfer from the metal to the aromatic ring, forming a radical anion. Regioselectivity in the reduction depends on whether substituents on the aromatic ring are electron donating groups or electron withdrawing groups. The Birch reduction can selectively reduce the less electron-rich ring in bicyclic aromatic compounds.
STEREOSPECIFIC REACTION, STEREOSELECTIVE REACTION, OPTICAL PURITY, ENANTIOMERIC EXCESS.. all these topics are explained in this slide with examples and formula.
STEREOSPECIFIC REACTION, STEREOSELECTIVE REACTION, OPTICAL PURITY, ENANTIOMERIC EXCESS.. all these topics are explained in this slide with examples and formula.
THIS SLIDE HAVE GOOD CONTENT. THIS SLIDE CONTAIN INTRODUCTION, STRUCTURE, RESONANCE, AROMATICITY, PHYSICAL AND CHEMICAL PROPERTIES, SYNTHESIS AND APPLICATION OF QUINOLINE.
This slides discusses about Isoquinoline nucleus (fused heterocyclic compound). this ring contain benzene ring fused with pyridine nucleus with nitrogen atom
This slide discusses about basic indole nucleus, its chemistry, synthesis, reactions and medicinal uses of Indolyl derivatives..Indole is basically fused heterocyclic compound
The ppt is made for college purposes. I'm a student and I had to present Birch Redution Mechanism. The ppt gives an insight to Birch Reduction. The sturctures of Mechanism is drawn is such a way that they are useful for better understanding of the topic. Thank you, I hope you like and and it will help you study better.
THIS SLIDE HAVE GOOD CONTENT. THIS SLIDE CONTAIN INTRODUCTION, STRUCTURE, RESONANCE, AROMATICITY, PHYSICAL AND CHEMICAL PROPERTIES, SYNTHESIS AND APPLICATION OF QUINOLINE.
This slides discusses about Isoquinoline nucleus (fused heterocyclic compound). this ring contain benzene ring fused with pyridine nucleus with nitrogen atom
This slide discusses about basic indole nucleus, its chemistry, synthesis, reactions and medicinal uses of Indolyl derivatives..Indole is basically fused heterocyclic compound
The ppt is made for college purposes. I'm a student and I had to present Birch Redution Mechanism. The ppt gives an insight to Birch Reduction. The sturctures of Mechanism is drawn is such a way that they are useful for better understanding of the topic. Thank you, I hope you like and and it will help you study better.
This presentation has all the points covered under the heading of halogenoalkanes from the syllabus of AS Level Chemistry 2014-15 as alloted by Cambridge.
Full study material of Alkyl and aryl halides, preparation, properties, polyhalo compounds, their uses with complete explanation with the relevant examples.
Theories of coordination compounds, CFSE, Bonding in octahedral and tetrahedral complex, color of transition metal complex, magnetic properties, selection rules, Nephelxeuatic effect, angular overlap model
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
3. The Birch reduction is an organic reaction where
aromatic compounds undergo partial reduction to 1,4-
unconjugated cyclohexadiene compounds in presence of
alkali metals in liquid ammonia i.e. solvated electrons.
M liq. NH3 M [H3N-------e-------NH3]
M = Na / Li (Solvated Electron)
H H
H H
M / Liq. NH3
(Aromatic) (Non-aromatic)
M = Na / Li
The reduction is conducted by Sodium or Lithium metal
in liquid ammonia at -33oC
3
4. The solvated electrons give an intense blue color to the
solution and have to be captured as the metal releases
them, otherwise with time the blue color fades as the
electrons reduce the ammonia to NH2
- and H2.
Li Li e [NH3]n
NH3 e NH2 H
1/2 H2
(Blue solution)
(Colorless solution)
4
5. The mechanism begins with a single electron transfer
(SET) from the metal to the aromatic ring, forming a
radical anion.
The anion then picks up a proton from the alcohol which
results in a neutral radical intermediate.
Formed neutral radical intermediate picks up one electron
to form anion followed by abstraction of proton from
alcohol results in the final unconjugated cyclohexadiene.
MECHANISM
5
7. Regioselectivity arises when there are substituents around
the aromatic ring.
REGIOSELECTIVITY
Electron Donating Groups such as alkyl or alkoxy groups
remains on the unreduced or Sp2 hybridised carbon atom
or ortho and meta carbon atoms are reduced.
EDG EDG
EDG = -OH, -OR, -NR2, -SR, -PR2, -alkyl, -CHO, -COOR
M / liq.NH3
Ortho Carbon reduced
from Sp2 to Sp3
Meta Carbon reduced
from Sp2 to Sp3
7
8. The Aldehydes and ester groups are in the electron
donation side because these are reduced to the
corresponding alcohols in Birch reduction prior to the
reduction of aromatic ring.
CHO CH2OH
M / liq.NH3 M / liq.NH3
CH2OH
COOR CH2OH
M / liq.NH3 M / liq.NH3
CH2OH
8
9. Electron Withdrawing Groups such as carboxylic acid
or primary amide groups remains on the reduced or Sp3
hybridised carbon atom or ipso and para carbon atoms
are reduced.
EWG EWG
EWG = -COOH, -CONH2
M / liq.NH3
Ipso Carbon reduced
from Sp2 to Sp3
Para Carbon reduced
from Sp2 to Sp3
9
10. If both Electron Withdrawing Groups and Electron
Donating Groups are present on the same ring.
COOH
COO
Li / liq.NH3
COOH
OMe
OMe
H3O+
O
COOH
Li / liq.NH3
COO
OMe
O O
OMe
Li / liq.NH3
COOH
10
11. COOH COOH
Li / liq.NH3
OMe OMe
Different products are obtained depending upon the
positions of EDG.
In case of both EWG & EDG present in the same ring.
EWG placed on reduced carbon and EDG on the
unreduced carbon
11
12. Selective reduction of less electron rich aromatic ring
occurs in the case of bicyclic aromatic compounds.
Li / liq.NH3
OH OH
Li / liq.NH3
N N
H
EtOH
EtOH
Electron rich due
to EDG OH
Electron poor due
to electronegative
atom Nitrogen
12
13. If one wants conjugated dienes, it is quite simple to
isomerise them using an acid catalyst.
Li / liq.NH3
EtOH
OMe OMe
H3O+
OMe
13
14. REFERENCES
Birch, A. J. J. Chem. Soc. 1944, 430–436.
https://www.name-reaction.com/birch-reduction
https://en.wikipedia.org/wiki/Birch_reduction
14