The reductive cleavage of benzylic carbon-sulfur bonds via an arene-catalysed lithiation process is described. The benzyllithium reagents generated were reacted with several electrophiles, mainly carbonyl compounds, affording the expected products in moderate to good yields.

The reaction of (5S,6S)-6-isopropyl-5-phenyl-1,4-oxazin-2-ones from glycine and alanine with formaldehyde in the presence of electron-deficient olefins afforded the corresponding adducts obtained by a diastereoselective 1,3-dipolar cycloaddition of the chiral azomethine ylids. Hydrolysis of these adducts allows the synthesis of enantiomerically enriched functionalized prolines

The regioselective allylation of 4-silyloxy quinolinium triflates with allyltri-n-butyltin has been performed to give 2- allyl-4-silyloxy-1,2-dihydroquinolines with excellent yields. Similiar results were obtained with 4-silyloxy benzopyrylium triflates and 4-silyloxy benzothiopyrylium triflates

Hydrolysis of bis(2,2,2-trifluoroethyl) 2,2-dimethylcyclopropane-1,1-dicarboxylate with pig liver esterase afforded (1R)-2,2-dimethyl-1-(2,2,2-trifluoroethoxycarbonyl)-cyclopropane-1-carboxylic acid in high enantiomeric excess. Via a Curtius type reaction with DPPA this compound was rearranged to (1S)-2,2,2-trifluoroethyl-2,2-dimethyl-1-[(N-ethoxycarbonyl)amino]-cyclopropane-1-carboxylate. Final alkaline hydrolysis gave (1S)-1-amino-2,2-dimethylcyclopropane-1-carboxylic acid.

A simple synthesis of cis-3-hydroxy-L-proline has been achieved starting from b -alanine making use of Sharpless asymmetric epoxidation as a key step in the synthesis

The aminopalladation-reductive elimination tandem reaction of internal and terminal alkynes containing proximate nitrogen nucleophiles has been proved to be a powerful and useful tool for the construction of the substituted pyrrole nucleus of the indole system. The fact that the reaction can be carried out with a wide assortment of organopalladium precursors and readily available starting alkynes, the ease of execution and the tolerance of a wide range of functional groups highlights its importance and flexibility and may contribute toward its utilization in the synthesis of complex indole derivatives. The method may provide a versatile complement of well established classical methods such as the Batcho-Limgruber synthesis of indoles from o-nitrotoluenes and dimethylformamide acetals, the Fisher indole synthesis, the Gassman synthesis of indoles from N-halo anilines, the Madelung cyclization of N-acyl-o-toluidines, and the reductive cyclization of o-nitrobenzyl ketones.

In the last few years we have extensively studied the base-promoted isomerization of oxiranyl ethers showing that they can be stereoselectively converted in a number of synthetically useful products by treatment with mixed metal reagents (superbases) [1,2]. Depending on the substrate and the base used oxiranyl ethers 1 can be transformed into hydroxy enethers 2 [3,4] (R’= H), di- and trisubstituted oxetanes 3 via a 4-endo process [5-7] (R’= H or alkyl), 1,4-diols 4 using an excess of base [8], tetrahydrooxepines 5 (R’’= CH=CH2) [9] and terminal allylic alcohols 7 (R’’= SPh) when radical anions are used. The use of superbasic mixtures is essential in order to have processes with a highly regio- and stereoselective behaviour and high yields of converted products.

Novel heterogenized Pd catalyst, palladium supported by hydrotalcite[Pd(II)-hydrotalcite], has been synthesized. The catalyst is found to be effective for the oxidation of a wide range of alcohols using molecular oxygen as a sole oxidant. In this catalytic system, various alcohols are readily converted to the corresponding aldehydes or ketones selectively in high to excellent yields. It is noteworthy that the catalyst is also applicable to the oxidation of unsaturated alcohols such as geraniol and nerol without any isomerization of an alkenic part. Another characteristic property of this heterogeneous catalyst is that a shape selectivity depending on the structure of alcohols is observed in some extent. The catalyst has also advantages such as ease of handling, easy preparation, and reusability for several times without appreciable loss of the catalytic activity.

Several new pyrido[2,3,4-kl]acridines were synthesized by reacting naphthoquinone, juglone and cyclohexan-1,3-dione with b,b’-diaminoketones in a biomimetic reaction. The structure of all new compounds (6a, b, 8, 10, 11, 12, 14, 15, 16, 17a, b, 20, 21) was elucidated by NMR and MS spectroscopy. Elecrophilic substitution, mainly nitration, of the various compounds was undertaken and the substitution positions determined. A series of derivatives were prepared and their cytotoxicity towards P-388 mouse lymphoma cells analysed. The most cytotoxic derivatives were found to have IC50’s of 0.1 ug/ml.

The study of the stereochemistry of substituted prolines, synthesised by 1,3-dipolar cycloaddition reactions between azomethine ylides and alkenes employing substoichiometric amounts of Ag(I) is reported here