Renata Riva

Tandem reduction/intramolecular hydroxyalkylation of (3-hydroxyphenyl)alkanoates : a new regioselective approach to 1,8-dihydroxytetralins

Abstract 4-(3-hydroxyphenyl)-butanoates 4 , on treatment with DIBALH, followed by hydrolytic work-up, undergo a novel completely regioselective intramolecular hydroxyalkylation reaction to give 1,8-dihydroxytetralins. The yield of the reaction depends heavily on the structure of starting material, best results being achieved with 3,3-disubstituted butanoates.

Combination of Cross-Coupling and Metal Carbene Transformations for the Development of New Multicomponent Reactions

Multicomponent reactions (MCRs) are convergent chemical processes that involve condensation of more than two reactants to form a product, in which basically all or most of the atoms contribute to the newly formed molecule. Usually, MCRs involve the formation of multiple bonds in a single operation without isolating the intermediates or changing the reaction conditions, allowing the straightforward creation of molecular diversity and complexity from simple and readily available substrates. Moreover, the sustainable aspects of MCRs have been recently highlighted: atom economy and step efficiency reduce the number of intermediate steps, functional group manipulations, and use of protecting groups. All these characteristics explain the renewed interest of the synthetic community for MCRs in recent years.

Design of Multi-Component Reactions

Multi-component reactions (MCRs) have now been well established as a powerful synthetic tool for creating molecular complexity and diversity and are undoubtedly well suited for the drug discovery program. Another potential that has probably received less attention among synthetic chemists is the opportunity offered by MCRs for the development of new fundamentally important transformations (reactions). Indeed, although an MCR is composed of a series of known bimolecular reactions, the overall transformation could be novel. Consequently, it provides chemists the opportunities to uncover transformations that were otherwise difficult to realize. In this talk, we will present our recent work in this field, including: (1) the oxidative homologation of aldehydes to amides, (2) the oxidative coupling of aldehydes and isocyanides to α-ketoamides, (3) oxidative isocyanide-based MCRs, and (4) the enantioselective Passerini reaction.

Novel Reagents for Multi-Component Reactions

Ketenimines are a class of versatile and highly reactive intermediates that can participate in a variety of organic reactions, such as nucleophilic additions, radical additions, [2 + 2] and [2 + 4] cycloadditions, and sigmatropic rearrangements. In this presentation, we report on a series of multi-component reactions that involve a ketenimine intermediate. These reactions could furnish diverse heterocyclic compounds, including functionalized iminocoumarin, iminodihydroqunolines, iminothiochromens, pyrrolines, isoquinolines, pyridines, β-lactams, imino-1,2-dihydrocoumarins, and benzimidazoles.