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Organic chemistry: “Introduction to drawing resonance structures”. How to draw resonance structures. |
Resonance structures |
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Organic chemistry: “How to draw resonance structures”. The meaning of resonance. The purpose of resonance is to determine the locations of the charges. How to interpret electron-pushing arrows. Rules for drawing legal and significant resonance structures. |
Resonance structures |
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Organic chemistry: “Orbital hybridization. Sigma and pi bonds”. Hybridization of atomic orbitals: sp3, sp2, and sp hybridizations. Sigma vs. pi bonds. |
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Organic chemistry: “IUPAC alkane nomenclature”. IUPAC alkane nomenclature. Bond-line notation. How to draw all the structural isomers of a compound. Common names for branched substituents (isopropyl, isobutyl, sec-butyl, tert-butyl). Naming cyclic alkanes |
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Organic chemistry: “IUPAC nomenclature for branched substituents” |
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Organic chemistry: “R and S naming” |
Stereochemistry |
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Organic chemistry: “R and S naming problems”. |
Stereochemistry |
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Organic chemistry: “Stereochemistry”. Stereochemistry. Chiral carbons ("stereocenters") vs. chiral molecules. Meso molecules. Enantiomers and diastereomers. R and S naming |
Stereochemistry |
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Organic chemistry: “Stereochemistry and meso molecules” |
Stereochemistry |
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Organic chemistry: “Electron-pushing arrows”. How to use electron-pushing arrows, also known as “curved arrows,” to draw intermediates and products in reaction mechanisms. |
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Organic chemistry: more on electron-pushing arrows |
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Organic chemistry: “SN2—‘ionically bonded’ nucleophiles”. How to use electron-pushing arrows and numbering to draw the product of an SN2 reaction. How to recognize “ionically bonded” nucleophiles. |
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Organic chemistry: Three types of SN2 reaction |
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Organic chemistry: “SN2, SN1, E2, and E1 reactions” |
Reactivity and arrow-pushing |
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SN2, SN1, E2, E1 |
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Organic chemistry: “E2 reactions”. Introduction to the E2 mechanism. E2 stereochemistry--cis vs. trans, determined by anti-periplanar transition state. Protic vs. aprotic solvents. SN2 stereochemistry |
SN2, SN1, E2, E1 (this revised handout differs somewhat from the older version discussed in the video) |
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Organic chemistry: “SN2 and E2 topics”. How to determine whether a reaction will be SN2, SN1, E2, or E1.Sulfonates; the “tosyl” (Ts, toluenesulfonyl) group; “tosylate” (TsOR, toluenesulfonate). How to rank compounds in order of nucleophilicity. |
SN2, SN1, E2, E1 |
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Organic chemistry: “More on SN2, SN1, E2, and E1 reactions” |
Stereochemistry |
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SN2, SN1, E2, E1 (this revised handout differs somewhat from the older version discussed in the video) |
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Organic chemistry: “Some SN2, SN1, E2, and E1 topics”. Polar protic vs. aprotic solvents. Carbocationrearrangements. E2 and E1 regiochemistry (Zaitsev vs. Hofmann). Antiperiplanar transition state for E2; E2 andcyclohexane |
SN2, SN1, E2, E1 |
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Organic chemistry: “Introduction to Grignard reagents”. Reaction of Grignard reagents as bases with protic solvents. Reaction of Grignards as nucleophiles with aldehydes and ketones. Introduction to synthesis with Grignards. |
SN2, SN1, E2, E1 |
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Organic chemistry: “Alcohol nomenclature” |
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Organic chemistry: “Alcohols, oxidation, and reduction”. Oxidation of alcohols (PCC). Reduction of aldehydes andketones with Grignards to form alcohols. Synthesis with Grignards. Reduction of aldehydes with NaBH4 or LiAlH4 to form alcohols. |
Reduction and oxidation with alcohols |
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Organic chemistry: “Alcohols”. Reaction of alcohols with acids and bases. Oxidation and reduction involving alcohols—PCC, Grignard reagents. |
SN2, SN1, E2, E1 |
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Reduction and oxidation with alcohols |
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Organic chemistry: “Grignards”. How to make Grignards and alkyl lithiums (organometallics). Reactions of Grignardsand alkyl lithiums (with protic solvents, aldehydes and ketones, and epoxides/oxacyclopropanes). Synthesis problems—using radical halogenation, E2, SN2, oxidation (PCC), and Grignards for synthesis. The “retrosynthesis” technique for solving synthesis problems. |
Radical halogenation of alkanes |
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SN2, SN1, E2, E1 |
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Reduction and oxidation with alcohols |
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Organic chemistry: “Organometallics”. Halogenation of alcohols (PBr3, SOCl2). Organometallics (Grignards, alkyllithiums, organocuprates). Using the retrosynthesis technique to solve synthesis problems involving organocuprates(Gilman reagents). |
SN2, SN1, E2, E1 |
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R- and H- |
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Reduction and oxidation with alcohols |
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Organic chemistry: “Ethers”. Ethers. Williamson ether synthesis (preparation of ethers via SN2); retrosynthesis. Digression on how to remember the Brønsted-Lowry and Lewis definitions of acids and bases. Cleavage of ethers withhaloacid (HX). Effect of positive formal charges on reactivity. Effect of acid or base on reactivity. |
SN2, SN1, E2, E1 |
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Reactivity and arrow-pushing |
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Organic chemistry: “Oxacyclopropanes, also known as epoxides”. Oxacyclopropanes, also known as epoxides,oxiranes, or ethylene oxides. Ring strain. Synthesis of oxacyclopropanes with peroxycarboxylic acids (“peracids”) such as peracetic acid or MCPBA. Acid-catalyzed ring opening; ring opening with anionic nucleophiles; ring opening with lithium aluminum hydride (LiAlH4). Diol (“glycol”) synthesis--anti dihydroxylation of an alkene via hydrolysis ofoxacyclopropane intermediate; syn dihydroxylation of an alkene with osmium tetroxide (OsO4). Effect of a negative formal charge on reactivity. Regiochemistry of oxacyclopropane ring opening—when does the nucleophile attack the more substituted carbon and when does it attack the less substituted carbon? |
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Organic chemistry: “Introduction to proton NMR spectroscopy”. Introduction to proton NMR (nuclear magnetic resonance) spectroscopy. Equivalent vs. nonequivalent hydrogens; chemical shift; integration; spin-spin splitting. |
Proton NMR spectroscopy |
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Organic chemistry: “Another introduction to proton NMR”. Introduction to proton NMR (nuclear magnetic resonance) spectroscopy. Equivalent vs. nonequivalent hydrogens; chemical shift; integration; spin-spin splitting. Degrees ofunsaturation |
Proton NMR spectroscopy |
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Organic chemistry: “Proton NMR problems”. Proton NMR (nuclear magnetic resonance) problems |
NMR table and problems |
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Proton NMR spectroscopy |
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Organic chemistry: “Infrared spectroscopy problems” |
Problems discussed in the videos |
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Organic chemistry: “Introduction to mass spectrometry”. Mass spectrometry. Molecular/parent ion; base peak. Carbon-13; bromine and chlorine isotopes. Fragmentation and substitution |
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Organic chemistry: “Addition to alkenes: H2, HX, H2O”. Alkene addition reactions. Addition of H2 (hydrogenation).Electrophilic additions: addition of HX (hydrohalogenation); addition of H2SO4, H2O (hydration); addition of H2SO4, ROH. Addition of HX in presence of ROOR (radical addition using peroxide initiator). Regiochemistry: Markovnikovvs. anti-Markovnikov |
Alkenes |
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SN2, SN1, E2, E1 |
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Reactivity and arrow-pushing |
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Organic chemistry: “Alkenes: hydrogenation; addition of HX”. Addition reactions with alkenes: addition of H2(hydrogenation); electrophilic addition of HX (hydrohalogenation). Markovnikov vs. anti-Markovnikov. |
Alkenes |
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Organic chemistry: “Addition of halogens (HX or X2) to alkenes”. Addition to alkenes. Electrophilic addition of HX (halohydrogenation). Addition of H2 (hydrogenation). Addition of HBr with ROOR (radical addition). Addition of Br2or Cl2 (halogenation). |
Reactivity and arrow-pushing |
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Alkenes |
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Organic chemistry: “Alkenes: addition of HBr, BH3, X2”. Alkene addition reactions. Addition of H2 (hydrogenation). Addition of HBr, with or without peroxides. Addition of BH3 to get alcohols (hydroboration-oxidation). Addition of X2. |
Alkenes |
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Reactivity and arrow-pushing |
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Organic chemistry: “Hydrogenation and halogenation”. Alkene addition reactions. Problems involving degrees ofunsaturation and hydrogenation (addition of H2). E/Z naming of alkenes. Problems involving addition of X2(halogenation). Forming alkenes from alcohols via E1 (dehydration with H2SO4) or E2. |
Problems discussed in this video series |
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SN2, SN1, E2, E1 |
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Organic chemistry: “Synthesis of alcohols from alkenes”. Alkene addition reactions. Addition of HX, with or without peroxides. Addition of sulfuric acid and water (hydration). Addition of BH3 (hydroboration-oxidation).Oxymercuration-demercuration. Addition of X2 in alcohol. Creation of expoxides (oxacyclopropanes): from alkenes using MCPBA; from vicinal haloalcohols with base. Ozonolysis. |
Alkenes |
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Reduction and oxidation with alcohols |
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Organic chemistry: “Dihydroxylation of alkenes”. Alkene addition reactions. Addition of OsO4 (osmium tetroxide) to achieve syn dihydroxylation. Using epoxides to achieve anti dihydroxylation. A synthesis problem. The synthetic toolbox. When does steric hindrance block one face of a trigonal planar intermediate? |
Synthetic toolbox |
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Organic chemistry: “Synthesis using addition to alkenes”. Some synthesis problems involving alkenes and electrophilicaddition. |
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Organic chemistry: “Alkyne synthesis and reactions”. Electronegativity of alkyne carbons; acidity of alkynes; use ofalkynyl anions as nucleophiles for SN2 reactions and for attack on oxacyclopropanes (epoxides). Alkyne synthesis from dihaloalkanes by double elimination; alkyne synthesis from alkenes by halogenation-double dehydrohalogenation.Alkyne reactions. Hydrogenation of alkynes; hydrogenation of alkynes with Lindlar catalyst to form cis alkenes; sequential one-electron reduction of alkynes with sodium metal to form trans alkenes. Electrophilic addition of HX to alkynes; electrophilic addition of X2 to alkynes (halogenation). Enols; tautomerization; mercuric ion-catalyzed hydration of alkynes to form ketones |
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Organic chemistry: “Radical halogenation reactions”. Radical halogenation via radical chain mechanisms. Radicalhalogenation of alkanes (a radical substitution reaction). Radical allylic halogenation using NBS (radical substitution). Radical addition of hydrogen bromide to alkenes in the presence of peroxides (an anti-Markovnikov addition). |
Radical halogenation of alkanes |
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Alkenes |
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Organic chemistry: “Synthesis problems”. Single- and multi-step synthesis problems. (First-semester final exam review session.) |
Problems discussed in the videos |
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SN2, SN1, E2, E1 |
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Synthetic toolbox |
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Organic chemistry: “Organic chemistry tips” |
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Organic chemistry: “Electrophilic attack on conjugated dienes”. Conjugation. UV-vis (ultraviolet-visible) spectroscopy.Electrophilic attack on conjugated dienes (1,2- and 1,4-addition). |
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Organic chemistry: “Radical allylic halogenation”. Radical allylic halogenation using NBS (N-bromosuccinimide). |
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Organic chemistry: “A radical allylic halogenation problem”. A synthesis problem involving radical allylic halogenation |
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Organic chemistry: “Conjugated pi molecular orbitals”. Pi molecular orbital diagrams for conjugated systems. HOMO and LUMO |
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Organic chemistry: “Diels-Alder reaction”. Diels-Alder reaction. Dienes, dienophiles; s-cis, s-trans; electron-donating and electron-withdrawing substituents; “outside” vs. “inside” positions; “endo” vs. “exo” approaches. Molecular orbital diagram for Diels-Alder transition state (Frontier Molecular Orbital Theory); molecular orbital diagrams for endo vs.exo transition states. |
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Organic chemistry: “Retro Diels-Alder reaction”. The Diels-Alder and retro Diels-Alder reactions. A synthesis problem. |
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Organic chemistry: “Electrocyclic reactions”. Electrocyclic reactions (a type of “pericyclic” reaction”). Woodward-Hoffmann selection rules; conrotatory vs disrotatory. Molecular orbital explanation for the selection rules, using Frontier Molecular Orbital Theory |
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Organic chemistry: “Huckel’s rule: aromatic vs. antiaromatic”. Using Huckel’s rule to determine whether a molecule is aromatic, antiaromatic, or nonaromatic |
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Organic chemistry: “Benzenes and phenols”. Benzene nomenclature; “phenyl” vs. “benzyl”; ortho, meta, and para. Phenol nomenclature. Acidity of phenols. Deprotonated phenols as nucleophiles; preparation of alkyl aryl ethers using Williamson ether synthesis. Kolbe carboxylation. Hydrogenolysis of benzylic ethers |
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Organic chemistry: “Electrophilic aromatic substitution”. Electrophilic aromatic substitution (EAS) of benzene—halogenation, nitration, sulfonation, Friedel-Crafts alkylation and alkanoylation. Electron-withdrawing and electron-donating groups—activators vs deactivators, ortho/para-directors vs. meta-directors. |
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Organic chemistry: “Electrophilic aromatic substitution problems” |
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Organic chemistry: “Synthetic strategies for substituted benzenes”. Strategies for synthesizing substituted benzenes using electrophilic aromatic substitutions--interconversion of nitro and amino substituents; interconversion of alkanoyland alkyl substituents, Clemmensen reduction, disadvantages of Friedel-Crafts alkylation (rearrangements andoveralkylation); reversible sulfonation as a blocking procedure; moderating the activating power of amino and hydroxysubstituents. Arenediazonium salts; Sandmeyer reactions; synthesis of phenol from an arenediazonium salt. “Phenyl” vs. “benzyl”; oxidation of benzylic carbons to carboxylic acids with hot potassium permanganate (KMnO4) |
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Organic chemistry: “Nucleophilic aromatic substitution”. Nucleophilic aromatic substitution of benzene. Substitution through benzyne intermediates. Summary of methods for synthesis of phenols. Benzylic oxidation to carboxylic acids; synthesis problems involving benzylic oxidation. Radical benzylic halogenation |
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Organic chemistry: “Aldehydes and ketones. Acetals and ketals”. Nucleophilic attack on aldehydes and ketones; the three main categories of nucleophilic attack. A category 1 reaction: attack by a Grignard to form an alcohol. A category 2 reaction: attack by alcohol in acidic conditions to form an acetal or ketal. A category 2 “reverse” reaction: reaction of an acetal or ketal with aqueous acid to form an aldehyde or ketone. How treatment of reagents with acid or base affects reactivity |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “More on aldehydes and ketones”. Nucleophilic attack on aldehydes and ketones; the three main categories of nucleophilic attack. Two category 1 reactions: attack by a Grignard to form an alcohol; attack by LAH to form an alcohol. A category 2 reaction: attack by alcohol in acidic conditions to form an acetal or ketal. A category 2 “reverse” reaction: reaction of an acetal or ketal with aqueous acid to form an aldehyde or ketone |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “Aldehyde and ketone problems”. Aldehyde/ketone nomenclature problems. Spectroscopy problems. Hydration (nucleophilic addition of water to aldehydes and ketones to form geminal diols. Reactivity ofaldehydes and ketones. Effects of acid or base on reactivity. Mass spectrometry of aldehydes and ketones; McLaffertyrearrangement. Nucleophilic addition of thiols to aldehydes and ketones to form thioacetals; desulfurization ofthioacetals with Raney nickel. |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “Attack of amines on aldehydes and ketones”. Nucleophilic attack by amines on aldehydes andketones to form imines (category 3) and enamines (category 4). Wolff-Kishner reduction. Nucleophilic addition by hydrogen cyanide on aldehydes and ketones (category 1). The Wittig reaction (category 3); how to make phosphorusylides |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “Baeyer-Villiger oxidation”. Baeyer-Villiger oxidation of aldehydes and ketones to form esters. Oxidation of aldehydes to form carboxylic acids |
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Organic chemistry: “Enols and tautomerism”. Enols and enolates; tautomerism. Racemization at an a-carbon; deuterium exchange at an a-carbon. Enols as nucleophiles; acid-catalyzed a-halogenation. Boiling point of aldehydesand ketones |
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Organic chemistry: “Aldehydes, ketones, enolates”. Nucleophilic attack on aldehydes and ketones; acetals and ketals.Enolates. Ylides; Wittig reaction. Mechanism problems. |
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Organic chemistry: “Aldol condensation”. Enolates. Tautomerism between aldehydes or ketones and enols. Aldolcondensation |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “1,2- and 1,4-addition”. 1,2-addition and 1,4-addition (“conjugate addition”) to a,ß-unsaturatedaldehydes and ketones. (This video does not cover 1,2- or 1,4-addition to dienes; that material is covered in the video “Electrophilic attack on conjugated dienes”.) |
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Organic chemistry: “Michael addition. Robinson annulation”. Michael addition (conjugate addition of enolate ions). Robinson annulation (Michael addition followed by aldol condensation). |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “Naming aldehydes, ketones, carboxylic acids”. Nomenclature for aldehydes, ketones, carboxylic acids, and ethers. General names for the types of carboxylic acid derivatives |
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Organic chemistry: “Carboxylic acids and acid derivatives”. Acidity of carboxylic acids; ranking compounds in order of acidity. How to synthesize carboxylic acids: oxidation; carbonation; nitrile hydrolysis. The types of carboxylic acid derivative. The general pattern for nucleophilic attack on carboxylic acids and acid derivatives (addition-elimination).Esterification. Ranking carboxylic acids derivatives in order of reactivity |
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Organic chemistry: “Carboxylic acids”. Acidity of carboxylic acids; ranking compounds in order of acidity; acid/base reactions with carboxylic acids; extraction (laboratory separation technique). Carbonation (reaction of Grignard reagent with carbon dioxide to form carboxylic acid). Reduction of carboxylic acids with lithium aluminum hydride (LiAlH4, or LAH) to form alcohols. Reaction of carboxylic acids with SOCl2 (thionyl chloride) to form acyl chlorides.Decarboxylation |
Reactivity and arrow-pushing |
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Organic chemistry: “Nomenclature for carboxylic acid derivatives”. Nomenclature for acyl halides, anhydrides, esters, amides, nitriles. |
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Organic chemistry: “Carboxylic acid derivatives”. Nucleophilic attack on carboxylic acid derivatives, including hydrolysis, saponification, transesterification. |
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Organic chemistry: “More on carboxylic acid derivatives”. Nucleophilic attack on carboxylic acid derivatives, includingtransesterification, ester hydrolysis, attack by Grignards on esters, amide hydrolysis |
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Organic chemistry: “Hydrolysis of carboxylic acid derivatives”. Hydrolysis of carboxylic acid derivatives (acyl halides, anhydrides, esters, amides, and nitriles) to form carboxylic acids. Nucleophilic attack of alcohols and amines on carboxylic acids and acid derivatives to form esters and amides. Lithium aluminum hydride reduction of aldehydes andketones, carboxylic acids, and esters to form alcohols |
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Organic chemistry: “Claisen condensation. 1,3-dicarbonyls”. Overview of nucleophilic attacks on carboxylic acids and acid derivatives through the addition-elimination mechanism. How to make 1,3-dicarbonyls through the Claisencondensation; the Dieckmann condensation (intramolecular Claisen condensation). Reactions of 1,3-dicarbonyls—acetoacetic ester synthesis; malonic ester synthesis |
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Organic chemistry: “Reactions of enamines and enolates”. Enamine formation through attack of secondary amines onaldehydes and ketones; enamines as nucleophiles; alkylation of enamines; synthesis problems involving enamines. Aldolcondensation; crossed aldol condensation; intramolecular aldol condensation. Claisen condensation; intramolecularClaisen condensation; crossed Claisen condensation; Claisen condensation as a route to ketones. Acetoacetic ester synthesis; malonic ester synthesis. Michael addition; Michael acceptors; Michael donors |
Nucleophilic attack on aldehydes and ketones |
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Organic chemistry: “Introduction to amines”. Amine nomenclature. Nucleophilicity and basicity of amines. Synthesis of amines—through SN2, through lithium aluminum hydride (LAH) reduction of amides or nitriles, through the Gabriel synthesis, or through reductive amination. Overview of LAH reductions—of aldehydes and ketones, of carboxylic acids, of esters, of amides, and of nitriles. |
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Organic chemistry: “Basicity of aliphatic and aromatic amines” |
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Organic chemistry: “Carbohydrates”. Carbohydrates (sugars). D vs. L sugars; epimers. Ring formation; |
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Organic chemistry: “Introduction to amino acids and peptides”. Biochemistry. How to draw amino acids. Acid/base properties of amino acids. Finding net charge of amino acids and peptides (proteins) at a specified pH. pI of amino acids and peptides. Peptide (amide) bonds. Amino acid sequencing with partial digestion by proteolytic enzymes such as trypsin. Total acid hydrolysis (TAH) |
Amino acid table |
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Problem discussed in videos |
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Organic chemistry: “Amino acids and peptides”. Biochemistry--amino acids, peptides, and polypeptide sequencing. Acid/base properties of amino acids. How to draw amino acids at various pH’s. How to determine pI of a peptide;zwitterion. Acylation of the N-terminus; conversion of the C-terminus into an amide. Total acid hydrolysis (TAH). Sanger’s reagent and Dansyl chloride. Hydrazine (NH2NH2). Proteolytic enzymes--chymotrypsin, trypsin, thermolysin. A polypeptide sequencing problem |
Amino acid table |
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Problems discussed in videos |
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Organic chemistry: “Amino acid and polypeptide synthesis”. Amino acid synthesis--Gabriel synthesis; Streckersynthesis. Edman degradation. Polypeptide synthesis--Cbz (carbobenzoxy) and Boc (tert-butoxycarbonyl) amino-protecting groups; protection of the carboxy terminus via ester formation; DCC (dicyclohexylcarbodiimide) carboxy-activating reagent. An example of calculating pI and charge at a specific pH for a long polypeptide |
Amino acid table |