Myers Oxidation States of Organic Functional Groups and Reactions

Vocabulary flashcards covering organic oxidation functional group transformations, DMSO-mediated oxidations, hypervalent iodine reagents, chromium/ruthenium oxidants, and cleavage/unsaturation methods.

Swern Oxidation

A DMSO-mediated oxidation where 2 equivalents of DMSO are activated with oxalyl chloride in dichloromethane at or below $-60\,^\circ\text{C}$, followed by addition of an alcohol substrate and triethylamine to yield carbonyl compounds.

Pfitzner-Moffatt Procedure

The first reported DMSO-based oxidation procedure, using dicyclohexylcarbodiimide (DCC) as the electrophilic activating agent in conjunction with a Brønsted acid promoter typically at or near $23\,^\circ\text{C}$.

Parikh-Doering Procedure

A DMSO-mediated oxidation method that utilizes sulfur trioxide-pyridine ($SO_3\cdot\text{pyr}$) and triethylamine ($Et_3N$) to activate DMSO at reaction temperatures between $0\,^\circ\text{C}$ and $23\,^\circ\text{C}$.

Dess-Martin Periodinane (DMP)

A hypervalent iodine oxidant prepared from $o$-iodoxybenzoic acid (IBX) used for mild oxidation of sensitive alcohols to aldehydes or ketones with short reaction times while suppressing epimerization.

o-Iodoxybenzoic Acid (IBX)

A hypervalent iodine precursor to DMP that serves as a mild reagent for oxidizing alcohols to carbonyl compounds, converting 1,2-diols without C-C bond cleavage, and forming $\alpha,\beta$-unsaturated carbonyl compounds.

tetra-n-Propylammonium Perruthenate (TPAP)

A mild, catalytic perruthenate salt ($Pr_4N^+RuO_4^-$) used alongside stoichiometric $N$-methylmorpholine-$N$-oxide (NMO) and powdered $4\,\text{\AA}$ molecular sieves for alcohol oxidation at room temperature.

TEMPO (2,2,6,6-Tetramethyl-1-piperidinyloxyl)

A stable nitroxyl radical catalyst that promotes the oxidation of primary and secondary alcohols to carbonyl compounds in the presence of stoichiometric oxidants like BAIB, $NaOCl$, or Oxone.

Active Manganese Dioxide ($MnO_2$)

A heterogeneous, nonstoichiometric material ($MnO_x$, $1.93 < x < 2$) suspended in neutral media to selectively oxidize allylic, benzylic, and other activated alcohols.

Barium Manganate ($BaMnO_4$)

A deep green salt utilized without prior activation for the selective oxidation of primary and secondary allylic and benzylic alcohols to their corresponding aldehydes or ketones.

Oppenauer Oxidation

A classic equilibrium oxidation method achieved by heating an alcohol with a metal alkoxide catalyst in the presence of a carbonyl hydride acceptor, reversing the Meerwein-Pondorf-Verley reduction.

Collins Reagent

A hygroscopic red solid complex ($CrO_3\cdot\text{pyr}_2$) prepared by portionwise addition of solid chromium trioxide to pyridine, used in chlorinated solvents to oxidize alcohols rapidly.

Pyridinium Chlorochromate (PCC)

An air-stable yellow solid ($C_5H_5NH^+ClCrO_3^-$) known as Corey's reagent, used to oxidize primary/secondary alcohols and promote oxidative transposition of tertiary allylic alcohols.

Sodium Hypochlorite Oxidation ($NaOCl$)

An oxidation procedure in acetic acid solution that selectively converts secondary alcohols into ketones in the presence of primary alcohols.

Sodium Chlorite ($NaClO_2$)

A mild and selective reagent used for converting aldehydes into carboxylic acids under ambient conditions, frequently incorporating 2-methyl-2-butene as an electrophilic chlorine scavenger.

Silver Oxide ($Ag_2O$)

A classic oxidant used under strongly basic conditions ($NaOH$) to transform aldehydes directly into carboxylic acids.

Pyridinium Dichromate (PDC)

A bright orange solid ($(\text{pyr}H^+)_2Cr_2O_7^{2-}$) that converts non-conjugated aldehydes and primary alcohols to carboxylic acids in DMF, or alcohols to aldehydes when suspended in $CH_2Cl_2$.

Manganese Dioxide-NaCN-$CH_3OH$ Oxidation

A method to convert unsaturated aldehydes directly into methyl esters via cyanohydrin and acyl cyanide intermediates while preventing cis/trans isomerization.

Baeyer-Villiger Oxidation

An oxidative transformation converting ketones into esters or lactones via oxygen insertion into an acyl C-C bond using peroxyacids, proceeding with retention of stereochemistry at the migrating center.

Ruthenium Tetroxide ($RuO_4$)

A powerful oxidant generated in situ from catalytic $RuCl_3$ or $RuO_2$ with stoichiometric $NaIO_4$ in $CH_3CN/CCl_4/H_2O$ to convert alcohols into carboxylic acids or cleave alkenes.

Jones Oxidation

An oxidation procedure using Jones reagent (chromic acid in aqueous $H_2SO_4$) in acetone to convert primary alcohols/aldehydes to carboxylic acids and secondary alcohols to ketones.

Davis Oxaziridine

An $N$-sulfonyloxaziridine reagent used to perform $\alpha$-hydroxylation of enolates (particularly potassium enolates) to yield $\alpha$-hydroxy ketones.

MoOPH

Oxodiperoxymolybdenum(pyridine)hexamethylphosphoramide ($MoO_5\cdot\text{pyr}\cdot\text{HMPA}$), a peroxymolybdenum complex utilized to oxidize enolates into $\alpha$-hydroxy carbonyl compounds.

Rubottom Oxidation

A sequence involving the epoxidation of a silyl enol ether followed by silyl migration via an oxocarbenium ion intermediate to furnish $\alpha$-hydroxy ketones.

Fetizon's Reagent

Silver carbonate ($Ag_2CO_3$) absorbed on Celite, employed to selectively oxidize primary diols or lactols to lactones in refluxing nonpolar solvents like benzene or toluene.

Lead Tetraacetate ($Pb(OAc)_4$)

A strong oxidant employed for the oxidative cleavage of 1,2-diols and $\alpha$-hydroxyketones, as well as promoting oxidative cyclization via homolytic RO-Pb bond cleavage.

Sodium Periodate ($NaIO_4$)

A common stoichiometric reagent utilized for the selective oxidative cleavage of vicinal 1,2-diols into two carbonyl fragments.

Ozonolysis

The oxidative cleavage of alkenes using ozone ($O_3$) at low temperatures ($0\text{ to }-78\,^\circ\text{C}$) via a molozonide to an ozonide intermediate, followed by reductive or oxidative workup.

Lemieux-Johnson Oxidation ($OsO_4/NaIO_4$)

An alkene cleavage protocol combining catalytic osmium tetroxide ($OsO_4$) for initial dihydroxylation to 1,2-diols followed by periodate ($NaIO_4$) cleavage to form aldehydes or ketones.

Saegusa Oxidation

A two-step oxidation converting ketones into $\alpha,\beta$-unsaturated ketones via silyl enol ether formation followed by treatment with catalytic or stoichiometric $Pd(II)$.

Selenation/Oxidation/Elimination

A method to introduce $\alpha,\beta$-unsaturation to carbonyl compounds via enolate selenation (using $PhSeCl$ or $PhSeBr$), oxidation to a selenoxide, and syn-specific elimination.

Selenium Dioxide ($SeO_2$) Allylic Oxidation

A method for oxidizing alkenes to allylic alcohols proceeding via an initial ene reaction followed by a [2,3]-sigmatropic rearrangement.