Antonella De Mico

Radical Additions to Olefins in the Presence of Iodobenzenediacetate: an Easy Route to Alkyl Dithiocyanates

Abstract We describe a new application of iodobenzenediacetate (IBDA), which is able to oxidize thiocyanate anion to the corresponding radical. Subsequent addition to nucleophilic olefins leads to dithiocyanate derivatives. The radical addition to olefins is more effective when performing the thiocyanation reaction in presence of Mg(ClO 4 ) 2 or TEMPO.

The binary reagent PhI(OAc)2-Mg(CIO4)2:a SET induced ring enlargement of furan derivatives into pyranones

Abstract The binary reagent PhI(OAc) 2 -Mg(CIO 4 ) 2 is very efficient for a high conversion of (2-furyl)-1-alcohols into pyranones. The reaction mechanism can be explained in terms of a SET process, with the generation of a cation radical as key intermediate.

AuNPs-functionalized PANABA-MWCNTs nanocomposite-based impedimetric immunosensor for 2,4-dichlorophenoxy acetic acid detection.

In this work, we developed an impedimetric label-free immunosensor for the detection of 2,4-Dichlorophenoxy Acetic Acid (2,4-D) herbicide either in standard solution and spiked real samples. For this purpose, we prepared by electropolymerization a conductive polymer poly-(aniline-co-3-aminobenzoic acid) (PANABA) then we immobilized anti-2,4-D antibody onto a nanocomposite AuNPs-PANABA-MWCNTs employing the carboxylic moieties as anchor sites. The nanocomposite was synthesized by electrochemical polymerization of aniline and 3-aminobenzoic acid, in the presence of a dispersion of gold nanoparticles, onto a multi-walled carbon nanotubes-based screen printed electrode. Aniline-based copolymer, modified with the nanomaterials, allowed to enhance the electrode conductivity thus obtaining a more sensitive antigen detection. The impedimetric measurements were carried out by electrochemical impedance spectroscopy (EIS) in faradic condition by using Fe(CN)63-/4- as redox probe. The developed impedimetric immunosensor displayed a wide linearity range towards 2,4-D (1-100ppb), good repeatability (RSD 6%), stability and a LOD (0.3ppb) lower than herbicide emission limits.

A facile route to iodohydrins and epoxides by oxidation of olefin-iodine complexes with pyridinium dichromate

Abstract Trisubstituted olefins, activated with I2, are changed into iodohydrins and epoxides by pyridinium dichromate. The conversion shows to proceed in regiospecific and stereospecific manner. Moreover some naturally occurring polyenes, submitted to similar treatment, afford selectively only terminal iodohydrins. These latter are converted into the corresponding epoxides through a new and convenient alumina supported reaction.

Photochemical behaviour of halogeno-thiophenes: synthesis of 5-arylthiophene-2-carboxylic esters

Abstract The arylation of 5-halogenothiophene-2-carbonitrile and methyl 5-halogenothiophene-2-carboxylate by a photochemical process was investigated. Whereas 5-bromothiophene-2-carbonitrile ( 3 ) is completely unreactive, the corresponding iodine derivative ( 4 ) furnishes the dehalogenation product. In contrast, methyl 5-iodothiophene-2-carboxylate ( 6 ) gives the corresponding aryl and heteroaryl derivatives in good yields on irradiation in the presence of various aromatic substrates (benzene, p -xylene, naphthalene, thiophene, 2-bromothiophene and 2-chlorothiophene). The different reactivities of compounds 3 , 4 and 6 can be explained on the basis of the proposed mechanism which involves the formation of an exciplex: compounds 3 and 4 do not give the arylation products probably because of their low intersystem crossing efficiency; the different behaviour of compounds 3 and 4 can be explained by considering the triplet energy of the molecules. An application of this conversion to the synthesis of a naturally occurring bithiophene isolated from Arctium lappa , 5′-(1-propynyl)-2,2′-bithiophene-5-carboxylic acid ( 13 ), is reported.

Hypervalent iodine induced nucleophilic additions to alkenes: Synthesis of 1,2-diperchlorates

Abstract a novel iodine (III) reagent has been developed by the BAIB/Mg(ClO 4 ) 2 reagent combination. Reaction of this reagent with alkenes yielded 1,2-diperchlorates.

Electrophilic assistance for cross-coupling reactions: A simple sythesis of mixed allylic ethers

Abstract Magnesium perchlorate, acting as a mild Lewis acid, is an efficient reagent for the synthesis of unsymmetrical ethers from allylic alcohols.

Photochemical synthesis of bithienyl derivatives

The application of a photochemical arylation of thienyl derivatives to the synthesis of bithienyl compounds is reported. The syntheses of 5-phenyl-2-propynylthiophene and 5-but-3-en-1-ynyl-2,2′bithienyl are described using as starting materials a phenylthienyl and a bithienyl derivative obtained by this method. Furthermore, the photochemical synthesis of halogenobithienyl ketones via the photochemical coupling of a halogenothiophene and 2-acetyl-5-iodothiophene is described. This methodology furnishes a new approach to the synthesis of natural bithienyls. All the synthesized compounds are singlet oxygen photosensitizers, and are, therefore, potentially bioactive compounds.

Photochemical synthesis of 3- and 5-aryl-2-furyl derivatives

Irradiation of 3- and 5-bromofuran-2-carbaldehyde in aromatic solutions furnished, in good yield, 3- and 5-aryl-2-furyl derivatives. Analogously, 4,5-dibromofuran-2-carbaldehyde (3) and 4,5-dibromo-2-furyl methyl ketone (5) are useful starting materials for the synthesis of the previously unknown 5-aryl-4-bromo-2-furyl derivatives. Irradiation (in diethyl ether) of the above compounds furnished the debromination products in high yields. This method represents an efficient procedure for the synthesis of 4-bromofuran-2-carbaldehyde (4).

Studies on the reactivity of 2,5-dimethoxy-2,5-dihydrofuran with phenylselenium reagents: Synthesis of highly functionalised C4 building blocks

Abstract PhSeCl adds stereospecifically to 1 , both in dichloromethane and methanol as solvents. The presence of zinc chloride allows to perform the methoxyphenylselenenylation of 1 .Both linear and cyclic acetals are converted by hydrolysis into C4 building blocks.