Sodium Percarbonate: A Mild Reagent for Conversion of Tosylhydrazones and Nitroalkanes to Carbonyl Compounds

Sodium percarbonate has been found to be a good reagent for oxidative regeneration of carbonyl compounds from tosyl hydrazones and nitroalkanes.     

Hypervalent Iodine in Synthesis. XIV. Facile Conversion of Tosylhydrazones to Carbonyl Compounds with Phenyliodine (III) Diacetate (PID)

Treatment of tosylhydrazones of ketones with PID in wet acetonitrile affords the corresponding parent ketones in excellent yields under mild conditions.     

A Mild Hydrogenolytic-Hydrolytic Conversion of Oximes to Carbonyl Compounds

Oximes are converted into the corresponding carbonyl compounds in high yields using Raney-nickel and sodium hypophosphite at pH 5.     

Conversion of Carbonyl Compounds to Olefins via Enolate Intermediate

A general and efficient protocol to synthesize substituted olefins from carbonyl compounds via nickel catalyzed C—O activation of enolates was developed. Besides ketones, aldehydes were also suitable substrates for the presented catalytic system to produce di‐ or tri‐ substituted olefins. It is worth noting that this approach exhibited good tolerance to highly reactive tertiary alcohols, which could not survive in other reported routes for converting carbonyl compounds to olefins. This method also showed good regio‐ and stereo‐selectivity for olefin products. Preliminary mechanistic studies indicated that the reaction was accomplished through nickel catalyzed C—O activation of enolates, thus offering helpful contribution to current enol chemistry.     

Rapid Regeneration of Carbonyl Compounds from Tosylhydrazones with Thallium Trinitrate(TTN)

Tosylhydrazones can be rapidly converted into corresponding carbonyl compounds in good to excellent yields with thallium trinitrate (TTN) under mild conditions.     

Direct Conversion of Silyl Ethers Into Carbonyl Compounds with Jones Reagent in the Presence of Potassium Fluoride

Treatment of silyl ethers with Jones reagent in acetone in the presence of potassium fluoride resulted in the silicon-oxygen bond cleavage and oxidation to give carbonyl compounds directly.     

Facile Transformation of N,N-Dimethylhydrazones and Tosylhydrazones to Ketones with Dimethyl Sulfate and Potassium Carbonate

N,N-Dimethylhydrazones and tosylhydrazones can be converted to their ketones in good to excellent yields with dimethylsulfate and K₂CO₃.     

Oxidation of Benzylic Alcohols to Carbonyl Compounds with Potassium Permanganate in Ionic Liquids

Abstract

The selective oxidation of primary and secondary benzylic alcohols with potassium permanganate in ionic liquids to give corresponding aldehydes and ketones in 83–97% yields has been described.     

Selective Protection of Carbonyl Compounds as Azines and Their Facile Regeneration

Carbonyl compounds with freshly prepared hydrazinium formate successfully yielded the corresponding azines in excellent yields. In turn, azines were deprotected to the corresponding carbonyls using triethylammonium chlorochromate chemoselectively.     

A Facile Ester Homologation of Carbonyl Compounds Via Ketene-O,S-Acetals

A usefull extension of the available methods for the conversion of carbonyl compounds into ketene-O,S-acetals^1,2,3 has been found in the Peterson olefination with methoxyphenylthiotrimethylsilyl-methyllithium 1 of aldehydes and ketones. The starting material for this reagent 1 was prepared by reaction of methoxyphenylthio-methyllithium^4,5 with chlorotrimethylsilane at -80°C in THF. Deprotonation of the obtained methoxyphenylthiotrimethylsilyl-methane with n-butyllithium at -80°C in THF gave 1 and subsequent addition of the carbonyl compound at -80°C gave mixtures of Z and E ketene-O,S-acetals 2.     

Microwave Assisted Conversion of Oximes and Semicarbazones to Carbonyl Compounds Using Benzyltriphenylphosphonium Peroxymonosulfate

Summary.  Benzyltriphenylphosphonium peroxymonosulfate in the presence of catalytic amounts of bismuth chloride was found to be an efficient and mild reagent for the oxidative cleavage of oximes and semicarbazones to the corresponding carbonyl compounds under microwave irradiation. Corresponding author. E-mail: haji@cc.iut.ac.ir Received March 4, 2002; accepted (revised) April 8, 2002     

Mild Oxidative Conversion of Nitroalkanes into Carbonyl Compounds in Ionic Liquids

Basic hydrogen peroxide and sodium perborate were found to be cheap and efficient alternatives for the conversion of primary and secondary nitro to carbonyl compounds (Nef reaction) in ionic liquids.     

Facile Metal-Free Synthesis of 3-Aryl-4-Substituted Coumarins from O-Hydroxy Carbonyl Compounds

The intramolecular cyclization of the esters of salicylaldehyde, O-hydroxyacetophenones, methyl salicylate, and 2′-hydroxy chalcones by potassium hydroxide in pyridine leads to a short and convenient synthesis of 3,4-disubstituted coumarins. Twenty 3-phenyl coumarins were synthesized in 80–90% yields. No other by-product, such as 2-benzylchromone or β-diketones, was observed the reactions. The mild reaction condition involves the removal of more acidic benzylic proton, which leads to a relatively cheap, nontoxic, metal-free method for the synthesis of 3-aryl-4-substituted coumarins.     

Facile Conversion of Red Phosphorus into Soluble Polyphosphide Anions by Reaction with Potassium Ethoxide

Soluble polyphosphide anions were successfully generated in a number of organic solvents by the reaction between shelf‐stable red phosphorus and potassium ethoxide. The species were identified by ³¹P NMR spectroscopy in solution and by X‐ray crystal‐structure determination of (Bu₄N)₂P₁₆ in the solid state. The reaction was scaled up to gram quantities by using a flow‐chemistry process.     

A Selective Conversion of Benzylic Alcohols to the Corresponding Carbonyl Compounds by Means of an Ag(III) Complex

 Carbonyl compounds of the type XPhCOR (R = H, Me, Ph; X = H, Me, Cl, Br) are prepared in high yields by reaction of the corresponding benzylic alcohols XPhCHOHR with KNa₄ [Ag(HIO₆)₂]×12H₂O in alkaline solution. This method allows the selective oxidation of benzylic alcohols in compounds containing other types of alcoholic functional groups.     

A Selective Conversion of Benzylic Alcohols to the Corresponding Carbonyl Compounds by Means of an Ag(III) Complex

Summary.  Carbonyl compounds of the type XPhCOR (R = H, Me, Ph; X = H, Me, Cl, Br) are prepared in high yields by reaction of the corresponding benzylic alcohols XPhCHOHR with KNa₄ [Ag(HIO₆)₂]×12H₂O in alkaline solution. This method allows the selective oxidation of benzylic alcohols in compounds containing other types of alcoholic functional groups. Received January 18, 2000. Accepted (revised) February 23, 2000     

Electroinduced Addition of Fluoroalkyltrimethylsilanes to Carbonyl Compounds

Generation of a radical anion of a carbonyl compound in the presence of fluoroalkyltrimethylsilanes results in a chain reaction of addition to the carbonyl group with the generation of corresponding silyl ethers at a current efficiency of up to 7000%. A similar reaction is realized when zinc dust is used as the reductant.