Rearrangement to Electron Deficient Carbon
Rearrangement to Electron Deficient Nitrogen
Rearrangement to Electron Deficient Oxygen
Rearrangement to Electron-Rich Carbon
Aromatic Rearrangements
Rearrangement to Electron Deficient Carbon
Rearrangement to Electron Deficient Nitrogen
Rearrangement to Electron Deficient Oxygen
Rearrangement to Electron-Rich Carbon
Aromatic Rearrangements
STEREOSPECIFIC REACTION, STEREOSELECTIVE REACTION, OPTICAL PURITY, ENANTIOMERIC EXCESS.. all these topics are explained in this slide with examples and formula.
Molecular Rearrangements of Organic Reactions ppsOMPRAKASH1973
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This PPT is usefull for aspirants of JEE-IIT, CSIR-NET and UPSC exams in CHEMISTRY section. It is also usefull for grduates and Post graduates students of Indian Universities.
An organic species which has a carbon atom bearing only six electrons in its outermost shell and has a positive charge is called carbocation.
The positively charged carbon of carbocation is sp2 hybridized.
The unhybridized p-orbital remains vacant.
They are highly reactive and act as reaction intermediate.
They are also called carbonium ion.
What is a Heterocyclic Compound?
A heterocyclic compound has at least two different elements as a member of its ring.
The most common hetero atoms found on a cyclic ring are Oxygen (O), Nitrogen (N) and Sulphur (S).
Example:
Nucleic Acid that is present in the body responsible for storing and expressing genetic information, is an example of a Heterocyclic compound.
Essential micronutrient, Vitamins is also an example of a heterocyclic compound.
The majority of drugs, pesticides, dyes, and plastics are examples of heterocyclic compounds.
Classification of Heterocyclic Compounds
Based on the electronic arrangement, we can classify Heterocyclic compounds into two types:
Aliphatic Heterocyclic Compounds
Aromatic Heterocyclic Compounds
Aliphatic Heterocyclic Compounds
Aliphatic heterocyclic compounds are those cyclic heterocycles that do not contain any double bond.
The properties of aliphatic heterocyclic compounds are mainly affected due to ring strain.
Examples of aliphatic heterocyclic compounds are Aziridine, Ethylene Oxide, Thiirane, Oxetane, Azetidine, Thietane, Tetrahydrofuran (THF), Dioxane, Pyrrolidine, Piperidine, etc.
Aromatic Heterocyclic Compound
Aromatic heterocyclic compounds, as the name suggests, are cyclic aromatic compounds.
Aromatic Heterocyclic compounds obey Huckels Rule, i.e.
It should be cyclic.
It should be planar.
It should not contain any sp3 hybridised atoms.
It must have (4n+2) 𝛑 electrons.
Aromatic Heterocyclic compounds are analogous to Benzene.
Examples: Furan, Pyrrole, Thiophene, Indole, Benzofuran, Carbazole, Quinoline, Isoquinoline, Imidazole, Oxazole, Pyrazole, Pyridazine, Pyrimidine, Purine, etc.
Based on structure, we can classify Heterocyclic compounds into five types:
Three-Membered Heterocyclic Compounds
Four-Membered Heterocyclic Compounds
Five-Membered Heterocyclic Compounds
Six-Membered Heterocyclic Compounds
Condensed or Fused Heterocyclic Compounds
Three-Membered Heterocyclic Compounds
These heterocyclic compounds contain three atoms which may be saturated or unsaturated.
Based on the number of heteroatoms present, we can further classify them into two categories:
STEREOSPECIFIC REACTION, STEREOSELECTIVE REACTION, OPTICAL PURITY, ENANTIOMERIC EXCESS.. all these topics are explained in this slide with examples and formula.
Molecular Rearrangements of Organic Reactions ppsOMPRAKASH1973
Â
This PPT is usefull for aspirants of JEE-IIT, CSIR-NET and UPSC exams in CHEMISTRY section. It is also usefull for grduates and Post graduates students of Indian Universities.
An organic species which has a carbon atom bearing only six electrons in its outermost shell and has a positive charge is called carbocation.
The positively charged carbon of carbocation is sp2 hybridized.
The unhybridized p-orbital remains vacant.
They are highly reactive and act as reaction intermediate.
They are also called carbonium ion.
What is a Heterocyclic Compound?
A heterocyclic compound has at least two different elements as a member of its ring.
The most common hetero atoms found on a cyclic ring are Oxygen (O), Nitrogen (N) and Sulphur (S).
Example:
Nucleic Acid that is present in the body responsible for storing and expressing genetic information, is an example of a Heterocyclic compound.
Essential micronutrient, Vitamins is also an example of a heterocyclic compound.
The majority of drugs, pesticides, dyes, and plastics are examples of heterocyclic compounds.
Classification of Heterocyclic Compounds
Based on the electronic arrangement, we can classify Heterocyclic compounds into two types:
Aliphatic Heterocyclic Compounds
Aromatic Heterocyclic Compounds
Aliphatic Heterocyclic Compounds
Aliphatic heterocyclic compounds are those cyclic heterocycles that do not contain any double bond.
The properties of aliphatic heterocyclic compounds are mainly affected due to ring strain.
Examples of aliphatic heterocyclic compounds are Aziridine, Ethylene Oxide, Thiirane, Oxetane, Azetidine, Thietane, Tetrahydrofuran (THF), Dioxane, Pyrrolidine, Piperidine, etc.
Aromatic Heterocyclic Compound
Aromatic heterocyclic compounds, as the name suggests, are cyclic aromatic compounds.
Aromatic Heterocyclic compounds obey Huckels Rule, i.e.
It should be cyclic.
It should be planar.
It should not contain any sp3 hybridised atoms.
It must have (4n+2) 𝛑 electrons.
Aromatic Heterocyclic compounds are analogous to Benzene.
Examples: Furan, Pyrrole, Thiophene, Indole, Benzofuran, Carbazole, Quinoline, Isoquinoline, Imidazole, Oxazole, Pyrazole, Pyridazine, Pyrimidine, Purine, etc.
Based on structure, we can classify Heterocyclic compounds into five types:
Three-Membered Heterocyclic Compounds
Four-Membered Heterocyclic Compounds
Five-Membered Heterocyclic Compounds
Six-Membered Heterocyclic Compounds
Condensed or Fused Heterocyclic Compounds
Three-Membered Heterocyclic Compounds
These heterocyclic compounds contain three atoms which may be saturated or unsaturated.
Based on the number of heteroatoms present, we can further classify them into two categories:
Chemistry of aromatic amines, Classification of amines, Preparation, reactions of amines, synthetic uses of aromatic amines, basicity of aromatic amines and factor affecting basicity amine.
Cyclohexane exists in different conformations viz chair, boat, twist boat and half chair. These conformations possess different energies. Therefore they differ in energy.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
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The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
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Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
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Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
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In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Embracing GenAI - A Strategic ImperativePeter Windle
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Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
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Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
1. BY
Dr. M. T. Bachute
DEPARTMENT OF CHEMISTRY
K. B. P. Mahavidyalaya, Pandharpur
2. The rearrangement which converts an AMIDE to
an AMINE with one carbon atom less by the action of alkaline
hypohalite or bromine in alkali is known as Hofmann
rearrangement or reaction.
Amides which do not have a substitution on the
NITROGEN display molecular rearrangement to primary amines.
In this rearrangement, the carbonyl carbon
atom of the amide is lost and the R group of amide gets attached to
the nitrogen of the amine.
3. The reaction is as follows :-
O
||
R-C-NH2 + Br2 + 4NaOH R-NH2 + 2NaBr + Na2CO3 + 2H2O
An amide 10 amine
Hofmann Rearrangement
H2O
MECHANISM :- The reaction is believed to proceed through following
steps---
Step 1: Bromination of nitrogen.
Step 2: Extraction of H +by OH - & rearrangement of anion.
Step 3: Hydrolysis.
4. O O
|| ||
R-C-NH2 + Br2 R-C-NH-Br
An amide N-bromamide
..
O O
|| ||(-)
R-C-NH-Br + OH- R-C-N-Br + H2O
N-bromamide Bromamide anion
(UNSTABLE)
..
..
O O
|| ||
R-C-N-Br R-C-N + Br -
Acyl nitrene
..
..
..
..
O
||
R-C-N R-N=C=O
Isocyanate
..
.. ..
Actual
rearrangement
Electron
deficient
..
..
5. R-N=C=O + H2O R-NH2 + CO32-
Isocyanate Amine Carbonate
ion
.. ..2OH-
The Hofmann rearrangement involves a 1,2-shift of group with its
electron pair to an electron-deficient NITROGEN.
6. STEREOCHEMISTRY :-
An interesting stereochemical observation is that if
the migrating group (R) is chiral , its configuration is retained in the
product amine.
Thus this rearrangement is INTRAMOLECULAR ,
the migrating group does not become free , but remains attached with
the substrate in some way e.g. via bridged transition state.
7. That the rearrangement is intramolecular has been supported by following
evidences:--
1.When the HR is carried out with mixture of m-deuteriobenzamide
& benzamide, only m-deuterioaniline & aniline are formed. This shows
that the rearrangement is intramolecular, if it is intermolecular then the
cross-products such as aniline & m-deuterioaniline are formed.
D
CONH2
+
CONH2
D
D
NH2
NH2 NH2
NH2
m-deuteriobenzamide benzamide
Intramolecular
Intermolecular
m-deuterioaniline aniline
Cross-products not formed
HR
8. 2.When optically active α-phenylpropionamide undergoes HR, then
α-phenylethylamine having the same configuration is formed.
CH3 O CH3
||
H C C NH2 H C NH2
C6H5 C6H5
Br2
KOH
α-Phenylpropionamide α-Phenylethylamine
9. RATE OF HOFMANN REACTION:-
In Hofmann rearrangement, N-Bromamide rearranges to
isocyanate is one step with a loss of bromide ion.This is a slow step.
Further, in arylamides,i.e., when the migrating group is aryl,
then the rate of Hofmann reaction gets increased by presence of
electron-releasing substituents in the aromatic ring.
For e.g.,in the case of substituted benzamide as :--
CONH2G NH2GOBr-
10. The reactivity of G is of the following order :---
OCH3 > CH3 > H > Cl > NO2
3. In the preparation of anthranilic acid from phthalamide
2. Preparation of aldehyde
APPLICATIONS :-
1. Synthesis of 10 aliphatic & aromatic amines
11. APPLICATIONS:-
1. Synthesis of 10 aliphatic & aromatic amines:-
The HR is useful for conversion of carboxylic acids &
their derivatives into 10 amines having one carbon atom less than the
starting material.
COOH COOH
Br Br Br
CONH2 NH2
Benzoic acid P-Bromoaniline
Br2
FeBr3
i) SOcl2
ii) NH3
Br2
KOH
12. i) Preparation of methylamine, aniline, benzylamine, etc. :-
CH3CONH2 CH2NH2
C6H5CONH2 C6H5NH2
C6H5CH2CONH2 C6H5CH2NH2
H2N.CO.NH2 H2N-NH2
UREA HYDRAZINE
Br2/KOH
13. ii) Preparation of β-aminopyridine :-
It is prepared from the nicotinamide, because it
cannot be produced in good yield via the nitration of pyridine.
Br2 / KOH (65-70%)
iii) Preparation of amino acids ;-
β-Alanine is prepared (45% yield) by treating
succinimide with bromine & aq.caustic potash, reaction takes place
through the haloamide of succinic acid.
14. CH2-CO CH2CONH2 CH2NH2
CH2-CO CH2COO- CHCOO-
NH
OH-
Br2
KOH
β-Alanine
iv) Synthesis of anthranilic acid :-
Anthranilic acid is basic starting material for
preparation of ortho-disubstituted benzene derivatives.
C
C
O
O
||
||
O
C
C
NH
||
O
COOH
CONH2
O
||
COOH
NH2
Phthalic anhydride Phthalimide Anthranillic acid
NH3
-H2O
Cl2
NaOH
HR
Succinimide
15. 2. Preparation of aldehyde:-
Hofmann reaction is used to convert α,β-unsaturated acids
& α-hydroxy acid amides into aldehyde.
R.CH=CH.CONH2 R.CH=CH.NHCOCH3
R-CHO
Cl2/NaOH
HCl
16. REFERENCES:-
1. Organic chemistry by MORRISON & BOYD ; 6th edition ; 874-877.
2. Reaction mechanism & reagents in organic chemistry by
GURDEEP R.CHATWAL ; 725-729.
3. Advanced organic chemistry by JERRY MARCH ; 4th edition ; 1090-
1091.
4. Organic name reactions and molecular rearrangement by
GURDEEP RAJ .