Mauro Panunzio

Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their “metallo-imines” variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as “privileged” ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

Inversion of configuration of alcohols through nucleophilic displacement promoted by nitrate ions.

Abstract Inversion of configuration of hydroxy functionalities in biologically significant structures has been performed under mild conditions through nucleophilic displacement by nitrate ion.

A synthetic approach to azetidinones from nitriles and lithiumtriethoxyaluminium hydride.

Abstract A convenient one-pot process for direct conversion of nitriles to 3,4-disubstituted azetidinones has been developed.

β-Lactam Antibiotics Renaissance

Since the 1940s β-lactam antibiotics have been used to treat bacterial infections. However, emergence and dissemination of β-lactam resistance has reached the point where many marketed β-lactams no longer are clinically effective. The increasing prevalence of multidrug-resistant bacteria and the progressive withdrawal of pharmaceutical companies from antibiotic research have evoked a strong reaction from health authorities, who have implemented initiatives to encourage the discovery of new antibacterials. Despite this gloomy scenario, several novel β-lactam antibiotics and β-lactamase inhibitors have recently progressed into clinical trials, and many more such compounds are being investigated. Here we seek to provide highlights of recent developments relating to the discovery of novel β-lactam antibiotics and β-lactamase inhibitors.

Chemistry of iron carbonyl anions: Selective reduction of nitroarenes and α, β-unsaturated carbonyl compounds, and reductive dehalogenation of organic halides by (C2H5)4N+ HFe3(CO)11−

Abstract The tetraethylammonium undecacarbonylhydridotriferrate [(C 2 H 5 ) 4 N + HFe 3 (CO) 11 − ] (I): which can be easily prepared in a two-step sequence from iron pentacarbonyl, triethylamine and tetraethylammonium chloride, selectively reduces nitroarenes to amines and α, β-unsaturated carbonyl compounds to the corresponding saturated compounds both in good yield. I reacts with some organic halides to give dehalogenated products.

Synthesis of perhydroxazin-4-ones. Competitive Mukaiyama versus hetero Diels–Alder reaction in the cycloaddition of 2-aza-3-trimethylsilyloxy-1,3-butadiene and aldehydes

Abstract The reactions of 2-aza-3-trimethylsilyloxy-1,3-butadiene with carbonyl dienophiles are described. 2-Aza-1,3-butadienes participate as dienes in the [4+2] cycloaddition with aldehydes to afford perhydroxazin-4-ones in good yields. Experimental results, however, show that a Mukaiyama type two-step reaction must be taken into account. The cycloadducts obtained have proved to be useful intermediates in the synthesis of α-amino-β-hydroxy acids.

N-Heteroarylmethyl-5-hydroxy-1,2,5,6-tetrahydropyridine-3-carboxylic acid a novel scaffold for the design of uncompetitive α-glucosidase inhibitors.

The enzyme α-glucosidase has attracted interest owing to its involvement in the digestive process of carbohydrate, its role in intracellular glycoprotein trafficking, tumorigenesis and viral infection. In this study, several members of a new family of N-heteroarylmethyl substituted azasugars were synthesized and evaluated as α-glucosidase inhibitors. We systematically investigated the effect of different N-substituents as well as the role of hydroxyl and carboxylate moieties on the piperidine ring. The compounds N-heteroarylmethyl-5-hydroxy-1,2,5,6-tetrahydropyridine-3-carboxylic acid emerged as potent α-glucosidase inhibitors. Unlike Acarbose and other clinically relevant α-glucosidase inhibitors, these compounds act through a reversible uncompetitive mechanism of inhibition which make them attractive candidates for drug development.

Synthesis of (1,5-cis-5,6-trans-6,7-trans)-2-oxa-3-methoxy-6-ethoxycarbonyl-7-benzoyl oxy bicyclo /3.3.0/ octane : An useful synthon in the prostaglandins field

Abstract The target molecule ( 11 ), a precursor of PG, has been prepared by a novel fully stereoselective methodology “via” cyclopentandione ( 2 ), starting from ethyl acetoacetate and ethyl-2-bromo-pentenoate.

Chemistry of alkali metal tetracarbonylferrates. A simple method for alkylating and arylating carbonyl compounds and active methylene compounds

Alkylation and arylation of carbonyl compounds and active methylene compounds by means of aldehydes in the presence of potassium tetracarbonylhydridoferrate is described. This reagent reduces benzylideneacetone to benzylacetone under the same conditions. A reaction scheme is suggested. An alternative approach utilizes disodium pentacarbonylchromate to prepare 1,3-diphenylpropan-1-one.

Reduction of 5-Nitrosalicylic Acid in Water to Give 5-Amino-salicylic Acid*

In the course of a general programme aimed to find new protocols for environmentally friend chemistry [1-3] we were looking for a clean, high yielding method of reduction of 5-nitrosalicylic acid (1) to 5-aminosalicylic acid (5-ASA) in industrial scale [4].[...]