Syntheses of Isoxazoline-Based Amino Acids by Cycloaddition of Nitrile Oxides and Their Conversion into Highly Functionalized Bioactive Amino Acid Derivatives

The present account illustrates the syntheses of isoxazoline- based amino acids by the cycloaddition of 1,3-dipolar nitrile oxides to the C–C double bond of unsaturated amino acid derivatives, with focus on the regio- and stereoselectivities of the transformations. Emphasis is also placed on the syntheses of highly functionalized amino acids by means of isoxazoline ring opening. The syntheses of various pharmacologically active compounds and their analogues via the above strategies are described

Synthesis of novel fluorinated building blocks via halofluorination and related reactions

A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine- containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities

Ring-opening metathesis of some strained bicyclic systems; stereocontrolled access to diolefinated saturated heterocycles with multiple stereogenic centers

Ring-opening metathesis (ROM) of various unsaturated, constrained bicyclic ring systems has been investigated with the use of commercial ruthenium-based catalysts. Starting from various cyclodienes, the corresponding derived bicyclic lactone, lactam, and isoxazoline derivatives were submitted to ROM under ethenolysis. These functionalized, strained bicyclic systems afforded novel highly-functionalized diolefinated heterocyclic scaffolds in ROM reactions with stereocontrol, through the conservation of the configuration of the stereogenic centers of the starting compounds

Fluorination of some highly functionalized cycloalkanes: chemoselectivity and substrate dependence

A study exploring the chemical behavior of some dihydroxylated beta-amino ester stereo-and regioisomers, derived from unsaturated cyclic beta-amino acids is described. The nucleophilic fluorinations involving hydroxy-fluorine exchange of some highly functionalized alicyclic diol derivatives have been carried out in view of selective fluorination, investigating substrate dependence, neighboring group assistance and chemodifferentiation

Selective Functionalizations of Cycloalkene-Fused β-Lactams and their Transformations into Densely- Substituted Three-Dimensional Molecular Entities

Highly-functionalized, three-dimensional molecules have had an increasing impact in synthetic organic chemistry and pharmaceutical research over the past decades. Their syntheses and the development of novel synthetic approaches towards versatile, small molecules with chemical and structural diversity have generated great interest. We have designed various selective and stereocontrolled methodologies for the function- alization of cycloalkene-fused β-lactams with a common C C bond, as three-dimensional, functionalized scaffolds, involving the transformation of their ring olefin bond. The synthetic methodologies developed to access various pharmacologically interesting derivatives with multiple chiral centers might be valuable protocols for the preparation of other classes of organic compounds as well