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Conjugated Systems; Chapter 10
Linear conjugation versus cross conjugation in extended pi systems; care needs to be taken when deciding the actual extent of conjugation in polyunsaturated molecules. |
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The Diels-Alder Reaction; Chapter 10
Introduction to the Diels-Alder reaction in terms of stereochemical outcome and inference in mechanism. Discussion of endo and exo transition states. |
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The Diels-Alder Reaction; Chapter 10
Further examples of Diels-Alder cycloaddition reactions and stereochemical outcomes. Additional discussion of endo and exo possibilities. |
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Aromaticity; Chapter 11
An introduction to the requirements for aromaticity, Huckel's rule, and the diversity of aromatic and heteroaromatic compounds found in Organic Chemistry and Biochemistry. |
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Aromaticity; Chapter 11
Criteria used for counting the electrons in both aromatic and non-aromatic pi systems, including carbon and heteroaromatic systems with lone pairs. |
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Aromaticity; Chapter 11
The Frost circle, a device for determining the populations of bonding, non-bonding, and antibonding orbitals in conjugated cyclic systems. |
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Electronic Effects in EAS; Chapter 12
A discussion of the different effects that substituents on a benzene system have on the reactivity of the ring, as well as the effect on electron density at each carbon within the cycle. |
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Directing Effects in EAS; Chapter 12
Substituent effects in Electrophilic Aromatic Substitution; how each type of group either stabilizes or destabilizes the intermediate cation and how that influences product distribution. |
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Heteroaromatics: Chapter 12
The aromatic heterocycles pyridine and pyrrole are compared and charaterized as being electron-poor and electron-rich, respectively, based on the resonance possibilities within the cycles. |
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Heteroaromatic Reactivity; Chapter 12
A description of the reactivity of electron-poor and electron-rich heterocyles in the presence of electrophiles and nucleophiles; lone pair inclusion in the aromatic sextet being key. |
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Introduction to Infra-Red Spectroscopy; Chapter 13
Infra-Red spectroscopy is discussed from the basics of bond vibration to the assembly of the IR spectrometer; examples of output (spectra) and interpretation are given. |
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Nuclear Magnetic Resonance Spectroscopy; Chapter 13
A Flash-based exercise on how to determine the number and type of protons in an organic molecule. The examples should be studied in conjunction with the Spectroscopy Sheet. |
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Nuclear Magnetic Resonance Spectroscopy; Chapter 13
A second Flash-based exercise in NMR spectroscopy in which proton spectra are matched to one of three possible molecules. Use the Spectroscopy Sheet to practice working with spectra. |
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Nuclear Magnetic Resonance Spectroscopy; Chapter 13
The superconducting magnets required for modern NMR (Nuclear Magnetic Resonace) spectroscopy need to be cooled to liquid helium temperatures to work; usually a "quench" is very bad news. |
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Mass Spectrometry basics; Chapter 13
Mass spectrometry is a very sensitive technique used in Chemistry and Forensic Science to identify organic and biological molecules; the spectra reveal information about structure and isotope ratios. |
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Acid-base concepts; Chapter 14-20
A review of the important concepts that dictate the pKa of acids as they relate to organometallic stability and protonation of carbonyls in the upcoming chapters. |
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Carbanion stability; Chapter 14-20
Discussion of relative carbanion stability based on hybridization, resonance, and solvation effects; important for upcoming nucleophilic addition chemistry. |
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Organometallic reagents and reactions; Chapter 14
Carbon nucleophiles (carbanions) may be generated by reacting alkyl and aryl halides with metals such as Mg or Li. The polarization in these reagents allows them to react as carbon nucleophiles. |
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Nucleophilic Addition reactions; Chapter 14-15
General concepts of nucleophilic addition to polarized carbonyl groups in aldehydes and ketones. Use of C-nucleophiles for C-C bond formation and of hydride reagents in reduction processes. |
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Esterification reactions; Chapter 15
Mechanisms of esterifications at differing pH. Use of acylation reagents (anhydrides, acyl chlorides) under basic conditions, as well as the Fischer esterification under acidic conditions. MolModAc Project, University of Illinois. |
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Ring-opening of Epoxides; Chapter 16
Discussion of the different ring-opening reactions that epoxides undergo. Acid-catalyzed opening at the more highly-substituted carbon (SN1-control); base-promoted opening at the less-hindered carbon (SN2 control). |
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Summary of Carbonyl Functional Groups; Chapters 17-20
A summary of the different classes of carbonyl compound encountered in the remaining chapters of the second semester. Classified generally as aldehydes/ketones and compounds with a heteroatom (potential leaving group) attached. Definition of alpha carbon. MolModAc Project, University of Illinois. |
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Acetals and Ketals; Chapter 17
Reactions of aldehydes and ketones to produce acetals and ketals, respectively. Mechanism of acid-catalyzed formation using alcohols and acid and experimental details of synthesis. Stability and use as protecting groups, as well as hydrolysis back to carbonyl. MolModAc Project, University of Illinois. |
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Formation of Imines; Chapter 17
Treatment of aldehydes and ketones to form imines and enamines. Nucleophilic addition of different amines followed by loss of water to produce C=N functional groups or elimination at the alpha C to give enamine species. MolModAc Project, University of Illinois. |
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The Wittig reaction; Chapter 17
The use of phosphonium ylides in addition to alkenes is discussed. The formation of the stable R3P=O species allows for a carbonyl to be turned into an alkene. The Wittig reaction mechanism is discussed in detail. MolModAc Project, University of Illinois. |
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Classes of Carbonyl Functional Groups; Chapters 17-20
Definitions of different carbonyl functional groups found in chemistry and biology. Overview of reactivity with nucleophiles and bases. Definition of alpha carbon and alpha,beta-unsaturated systems. MolModAc Project, University of Illinois. |
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Carboxylic Acids and Derivatives; Chapters 18-19
Classification of carboxylic acids and their derivatives such as esters, acid chlorides, anhydrides, and amides. Interconversion of each class of compound through nucleophilic acyl substitution. Effect of leaving group and nucleophile strength. MolModAc Project, University of Illinois. |
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Carboxylic Acids and Derivatives; Chapters 18-19
Reactivity of carboxylic acids and their derivatives. Nucleophilic acyl substitution mechanism to describe interconversion; discussion of leaving group ability as related to base and conjugate-acid strength. Reaction profiles to describe energetic changes. MolModAc Project, University of Illinois. |
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Carboxylic Acids and Derivatives; Chapters 18-19
Mechanisms of ester formation at different pH. Review of Fischer esterification process under acidic catalysis, and also of esterification in base using anhydrides and acid chlorides. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Discussion of the acidity of alpha protons in aldehydes, ketones, esters, etc. Effect of EWG on pKa and conjugate base strength. Relationship between enols and enolates and their use as nucleophiles in upcoming nucleophilic addition-type reactions. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Details of keto-enol tautomerism and the potential nucleophilicity of the alpha carbon. Similarity between enols and enamines (formed from aldehydes/ketones and secondary amines). Carbonyls with alpha H may therefore be sources of both electrophiles and nucleophiles. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Details of keto-enol tautomerism and the potential nucleophilicity of the alpha carbon. Similarity between enols and enamines (formed from aldehydes/ketones and secondary amines). Carbonyls with alpha H may therefore be sources of both electrophiles and nucleophiles. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Aldol reactions with two enolizable carbonyl starting materials. Equilibrium produces two nucleophiles and a mixture of products usually results. Reaction is made useful by employing one substrate that has an enolizable H and one that does not to limit mucleophilic species possible. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Claisen condensations with two enolizable ester starting materials. Equilibrium produces two nucleophiles and a mixture of products usually results. Reaction is made useful by employing one substrate that has an enolizable H and one that does not to limit mucleophilic species present. MolModAc Project, University of Illinois. |
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Enols and Enolates; Chapter 20
Michael reaction using stabilized enolates from 1,3-dicarbonyl compounds. 1,2- versus 1,4-addition (kinetic versus thermodynamic processes). Formation of enol and subsequent tautomerism to reveal ketone product. MolModAc Project, University of Illinois. |