Letizia Sambri

Bio: Letizia Sambri is an academic researcher from University of Bologna. The author has contributed to research in topics: Lewis acids and bases & Enantioselective synthesis. The author has an hindex of 40, co-authored 188 publications receiving 4349 citations. Previous affiliations of Letizia Sambri include University of Camerino & University of Calabria.

Organocatalytic Asymmetric Conjugate Addition of 1,3‐Dicarbonyl Compounds to Maleimides

Abstract: The enantioselective construction of quaternary stereogenic centers bonded to four carbon atoms by efficient asymmetric methods is a great synthetic challenge, as the creation of such complex fragments is complicated by steric factors. Currently, despite the substantial progress that has been made in the last few years, only a few catalytic asymmetric C C bondforming strategies have proven to be useful for forming quaternary carbon centers. Among them, the catalytic conjugate addition of compounds with a prochiral trisubstituted nucleophilic carbon atom to b-substituted Michael acceptors constitutes an effective approach for the asymmetric construction of highly functionalized products with adjacent quaternary and tertiary carbon centers. The stereocontrolled, one-step synthesis of such important congested motifs from simple precursors is a formidable synthetic challenge, as the catalyst must provide high levels of stereoselectivity in a sterically demanding C C bond-forming process. To date, the acceptors employed in this powerful type of strategy have been enones, nitroalkenes, and unsaturated imides. Expansion of the scope of such an efficient strategy to other classes of Michael acceptors is a useful and challenging objective. Herein, we report the development of the first asymmetric direct conjugate addition of 1,3-dicarbonyl compounds to

Supramolecular Hydrogelators and Hydrogels: From Soft Matter to Molecular Biomaterials

Abstract: In this review we intend to provide a relatively comprehensive summary of the work of supramolecular hydrogelators after 2004 and to put emphasis particularly on the applications of supramolecular hydrogels/hydrogelators as molecular biomaterials. After a brief introduction of methods for generating supramolecular hydrogels, we discuss supramolecular hydrogelators on the basis of their categories, such as small organic molecules, coordination complexes, peptides, nucleobases, and saccharides. Following molecular design, we focus on various potential applications of supramolecular hydrogels as molecular biomaterials, classified by their applications in cell cultures, tissue engineering, cell behavior, imaging, and unique applications of hydrogelators. Particularly, we discuss the applications of supramolecular hydrogelators after they form supramolecular assemblies but prior to reaching the critical gelation concentration because this subject is less explored but may hold equally great promise for helping ...

Catalytic Functionalization of Indoles in a New Dimension

Abstract: 140 years ago Adolf von Baeyer proposed the structure of a heteroaromatic compound which revolutionized organic and medical chemistry: indole. After more than a century, indole itself and the complexity of naturally occurring indole derivatives continue to inspire and influence developments in synthetic chemistry. In particular, the ubiquitous presence of indole rings in pharmaceuticals, agrochemicals, and functional materials are testament to the ever increasing interest in the design of mild and efficient synthetic routes to functionalized indole derivatives. This Review emphasizes the achievements in the selective catalytic functionalization of indoles (C-C bond-forming processes) over the last four years.

Catalytic Asymmetric Synthesis of Oxindoles Bearing a Tetrasubstituted Stereocenter at the C‐3 Position

Abstract: The 3,3′-disubstituted oxindole structural motif is a prominent feature in many alkaloid natural products, which include all kinds of tetrasubstituted carbon stereocenters, spirocyclic or not, all-carbon or heteroatom-containing. The catalytic asymmetric synthesis of the tetrasubstituted carbon stereocenter at the C-3 position of the oxindole framework integrates new synthetic methods and chiral catalysts, reflects the latest achievements in asymmetric catalysis, and facilitates the synthesis of sufficient quantities of related compounds as potential medicinal agents and biological probes. This review summarizes the recent progress in this area, and applications in the total synthesis of related bioactive compounds.