Luigino Troisi

Oxidations by methyl trifluoromethyl dioxirane. Epoxidation of enol ethers

Abstract Isolated methyl trifluoromethyl dioxirane 4b has been employed to achieve the rapid, low temperature epoxidation of enol ethers, such as alkoxy(aryl)methylidene adamantanes 1a–e and methoxy(2-naphthyl)methylidene 2-bornane 1f , affording the corresponding spirooxiranes in excellent (92–97%) yields.

Simultaneous measurement of adenosine, dopamine, acetylcholine and 5-hydroxytryptamine in cerebral mice microdialysis samples by LC–ESI-MS/MS

A rapid and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been developed for the simultaneous measurement of adenosine (ADE), dopamine (DA), acetylcholine (ACh) and 5-hydroxytryptamine (5-HT) in mouse brain microdialysates. High method sensitivity (LLOQ of 0.05nM) was achieved by optimization of chromatographic and mass spectrometric parameters. The method was fully validated for its sensitivity, selectivity, matrix effect and stability. The LC-MS/MS method was successfully applied to evaluate the effect of the systemic administration of cocaine or amphetamine on the extracellular levels of ADE, DA, ACh and 5-HT in the mouse nucleus accumbens by microdialysis.

Electron-transfer chain isomerization of epoxides induced by one-electron oxidizing agents

Abstract One electron oxidizing agents have been employed to achieve the isomerization of epoxides to ketones. The reactions most likely proceed via a radical cation chain electron-transfer mechanism.

Synthesis of oxazolinyl aziridines

Abstract Aziridinyllithiums 4a and 4b , which are stable at low temperature, can be generated by deprotonation of 3a and 3b . Oxazolinyl aziridines 5a-j and 6a-b have been prepared by the reaction of oxazolinyl aziridinyllithiums 4a and 4b with electrophiles. Aziridines 6c and 6d were, instead, synthesized by a Darzens-like reaction from 2-(1-chloroethyl)-2-oxazoline 1b .

Palladium (II) catalyzed regioselective lactonization of steroids. Chemoselective construction of novel estrone derivatives

Abstract Palladium acetate and 1,4-bis(diphenylphosphino)butane (dppb) catalyze regioselective cyclocarbonylation of 4-allylsteroids forming exclusively 7-membered ring lactones with excellent yields (96–98 %). The stereoselective addition of an epoxide ring on the side-chain of steroids is realized by coupling the carbonyl group of the cyclopentanone ring of the steroid with 2-benzothiazolylchloromethyllithium 1 or 4,4-dimethyl-2-oxazolinylchloroalkylithiums 2 and 3 .

Novel and Recent Synthesis and Applications of β-Lactams

In this chapter, a comprehensive overview of the most significant and interesting contributions published from 2000 until now, concerning the preparation of novel β-lactam structures is presented. Among the different synthetic strategies available, either novel or already known but efficient and versatile methodologies are covered. The simple modifications of one or more substituents linked to the nitrogen N-1, the C-3, and the C-4 carbon atoms of the β-lactam nucleus were considered as an alternative synthetic protocol of more complex and polyfunctionalized molecules. Indeed, it is well known and extensively reviewed that the biological activity of this strained four-membered heterocycle is strictly dependent on the nature of the substituent groups that affect the reactivity towards the molecular active sites, increasing or lowering the possibility of interaction with the substrates. Finally, a synthetic survey of the most significant biological and pharmacological applications of the 2-azetidinones is reported.

Oxidation of enol ethers by metal(VI)oxide diperoxides

Abstract Alkoxy(aryl) adamantylidenes react with chromium(VI) or molybenum(VI) oxide diperoxides in CHCl 3 under argon yielding the corresponding 1,2-dioxetanes and/or carbonyl products derived from the fragmentation of the dioxetanes. The reaction most likely proceeds via preliminary epoxidation of the unsaturaled substrates.

Alkylation of heteroaryl alkyl metals by bistrialkylsilylperoxides

Abstract Heteroaryl alkyl metals 3 undergo methylation and ethylation upon treatment with bistrimethylsilylperoxide la and bistriethylsilylperoxide 1b . Benzothiazolylderivatives 3c-d and 3h-j react with la giving trimethylsilyloxylation other than methylation products. The reaction of 3a-b with la leads also to the trimethylsilylation product 1. The reaction of 3g , 3c and 3k with 1b provides the ethylated derivatives 2h , 2d and 2n respectively. No reaction occurred when 3c was treated with lc .

Palladium-catalyzed Cyclocarbonylation of Unsaturated Alcohols and Amines. Chemoselective Synthesis of Heterocycle-substituted γ- and δ-Lactones and Lactams

Unsaturated alcohols and amines react with carbon monoxide and hydrogen, in the presence of a catalytic amount of palladium acetate and a phosphine ligand, to afford selectively heterocycle-substituted γ- and δ-lactones and lactams. The distribution of five- and six-membered ring compounds can be modulated by an appropriate combination of solvent and phosphine ligand. The five-membered products are formed in two isomeric forms trans and cis with a modest diasteroselectivity (trans>cis).

Synthesis of 1,2-dioxetanes via electron-transfer oxygenation

Abstract Thermally stable 1,2-dioxetanes have been synthesized by the reaction of enol-ethers with tris p-bromophenylammoniumyl hexachloroantimonate via a chain oxygenation reaction involving formation of enol-ether cation radicals