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.     

Diethyl[trimethylsilylethoxymethyl]phosphonat - ein neuartiges reagens für variable aufbaustrategien von carbonyl-, α-hydroxycarbonylverbindungen und vinylphosphonaten

The carbanion of $\text{2}$ prepared by means of s-BuLi can be transformed stepwise with various electrophiles to the phosphonates $\text{3}$–$\text{5}$, opening via $\text{6}$ new approaches to carbonyl compounds $\text{7}$, phosphates of α-hydroxycarbonylderivatives $\text{8}$ and vinylphosphonates $\text{9}$.     

[11C]Carbonyl Difluoride—a New and Highly Efficient [11C]Carbonyl Group Transfer Agent

Herein, the synthesis and use of [¹¹C]carbonyl difluoride for labeling heterocycles with [¹¹C]carbonyl groups in high molar activity is described. A very mild single‐pass gas‐phase conversion of [¹¹C]carbon monoxide into [¹¹C]carbonyl difluoride over silver(II) fluoride provides easy access to this new synthon in robust quantitative yield for labeling a broad range of cyclic substrates, for example, imidazolidin‐2‐ones, thiazolidin‐2‐ones, and oxazolidin‐2‐ones. Labeling reactions may utilize close‐to‐stoichiometric precursor quantities and short reaction times at room temperature in a wide range of solvents while also showing high water tolerability. The overall radiosynthesis protocol is both simple and reproducible. The required apparatus can be constructed from widely available parts and is therefore well suited to be automated for PET radiotracer production. We foresee that this straightforward method will gain wide acceptance for PET radiotracer syntheses across the radiochemistry community.     

羰基化合物还原偶联为频呐醇反应的研究新进展

综述了近几年来羰基化合物还原偶联为频呐醇反应的研究新进展．     

Formation of β-Lactones by[2+2] Cycloaddition of Dichloroketene with Unreactive Carbonyl Compounds

We report a modified process that dichloroketene generated in situ from trichloroacetyl chloride and Zn powder reacts with unreactivate carbonyl groups to afford dichloro-β-lactones in moderate to good yields. Subsequently, monochloro-β-lactones, β-lactones and β-hydroxy ester are obtained by dechlorination under different reaction conditions.     

Synthesis of Functionalized Diethyl(pyrrolidin-2-yl)phosphonate and Diethyl(5-oxopyrrolidin-2-yl)phosphonate

Short and efficient syntheses of functionalized (pyrrolidin-2-yl)phosphonate and (5-oxopyrrolidin-2-yl)phosphonate have been developed. The synthetic strategy involved the diastereospecific 1,3-dipolar cycloaddition of N-benzyl-C-(diethoxyphosphoryl)nitrone to cis-1,4-dihydroxybut-2-ene and dimethyl maleate, respectively. O,O-Diethyl 3-carbamoyl-4-hydroxy(5-oxopyrrolidin-2-yl)phosphonate was obtained from O,O-diethyl 2-benzyl-4,5-dimethoxycarbonyl(isoxazolidin-3-yl)phosphonate by hydrogenation and subsequent treatment with ammonia, whereas transformation of O,O-diethyl 2-benzyl-4,5-dihydroxymethyl(isoxazolidin-3-yl)phosphonate into O,O-diethyl 3-aminomethyl-4-hydroxy(pyrrolidin-2-yl)phosphonate was accomplished by mesylation followed by hydrogenolysis to undergo intramolecular cyclization and the introduction of amino group via ammonolysis. Stereochemistry of the isoxazolidine cycloadducts, as well as the final functionalized (pyrrolidin-2-yl)- and (5-oxopyrrolidin-2-yl)phosphonates were established based on conformational analyses using vicinal H–H, H–P, and C–P couplings and supported by the observed diagnostic NOESY correlation signals.     

Reduction of Ozonides by Means of Polymeric Triphenylphosphine: Simplified Synthesis of Carbonyl Compounds from Alkenes

A classical system for the preparation of carbonyl compounds from alkenes relies upon ozonolysis of the double bond, followed by reductive cleavage of the ozonide so formed. Among the reagents of choice for such a reduction, triphenylphosphine certainly has enjoyed a widespread use.¹ However, in spite of the simplicity of the method, often one can face problems in the purification of the carbonyl compound from unreacted triphenylphosphine, especially if the polarities of both products are very similar. We have encountered such a problem during the preparation of the (20 S)-6β -ethoxy-3 α, 5-cyclo-5α -pregnane-20-carbaldehyde 4 from the suitably protected stigmasterol3². In this case, when triphenylphosphine was used for reduction of ozonide we never could isolate the aldehyde 2 uncontaninated by tripherylphosphine.     

羰基化合物在新型绿色能源有机钠离子电池中的应用

有机钠离子电池是一种以有机物作为电极材料的新型二次电池。但有机物作为钠离子电池电极材料仍存在较低的氧化还原电位、高的溶解性和低的导电性等问题。解决这些问题通常采用引入吸电子基团来提高氧化还原电位,形成聚合物来降低溶解性和引入导电基底增加导电性等方法。着重关注羰基化合物作为钠离子电池电极材料,分别介绍羰基化合物/聚合物及其与导电基底形成的复合物和柔性电极在钠离子电池中的应用。     

Determination of Carbonyl Compounds by High-Performance Liquid Chromatography

Carbonyl compounds in the form of 2,4-dinitrophenylhydrazones in alcoholic solutions were analyzed by high-performance liquid chromatography. This simple procedure is characterized by high sensitivity and reproducibility.     

A New HPLC Method to Determine Carbonyl Compounds in Air

In this paper,a new HPLC method was established to determine the earbonyl compounds in air.As the absorbent,2,4-dinitrophenylhydrazint(2,4-DNPH)reaeted with earbonyls specifieally,which form the corresponding 2,4-dinitrophenylhydrazones,then analyzed by HPLC.The chromatographic conditions,the recovery rate,stability of samples,reagent blank,sampling efficiency were all studied systematically.The results showed that this established method had high sensitivity and good selectivity compared with other analytical methods,and it can detemine ten earbonyl compounds in air in 26 min simultancously.     

Trifluoromethylsulfenylation of Masked Carbonyl Compounds

Incorporation of fluorine and fluorine containing groups such as trifluoromethyl and trifluoromethylthio moieties considerably enhances the biopharmacological properties of the parent precursors. Trifluoromethylsulfenylation of masked carbonyl functions, such as the enamines using N-(trifluoromethylthio)phthalimide is described in this communication.     

羰基化合物的直接还原氯代反应

在甲基二氯氢硅烷存在下,FeCl3催化羰基化合物(1)的还原氯代反应,合成了氯代烷烃(2)。较适宜的反应条件为:11.00 mmol,甲基二氯氢硅烷1.10 mmol,FeCl30.05 mmol,乙二醇二甲醚20 mL,回流反应3 h~12 h。在该反应条件下,1均可直接转化为2,收率65%~95%。     

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     

New Reactions of (2-Aminophenyl)diphenylmethanol with Carbonyl Compounds

Reactions of (2-aminophenyl)diphenylmethanol with ketones (dimedone, camphor, and 3-bromocamphor) in acetic acid result in the formation of arylimines of camphore and 3-bromocamphore, substituted tetrahydroacridin-1(2H)-one and 2-methyl-4,4-diphenylbenzoxazine.