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The rich reactivity profile of cyclopropanes has been extensively explored to trigger new organic transformations that enable unusual disconnective approaches to synthesize molecular motifs that are not easily reached through conventional reactions. In particular, the chemistry of cyclopropanes has received special attention in the last decade, with multiple new approaches that capitalize on the use of organocatalysis for the activation of the cyclopropane scaffold. This situation has also opened the possibility of developing enantioselective variants of many reactions that until now were only carried out in an enantiospecific or diastereoselective manner. Our group has been particularly active in this field, focusing more specifically on the use of aminocatalysis and Brønsted acid catalysis as major organocatalytic activation manifolds to trigger new unprecedented transformations involving cyclopropanes that add to the current toolbox of general methodologies available to organic chemists for the enantioselective synthesis of chiral compounds. [ABSTRACT FROM AUTHOR]

We have demonstrated that the catalytic and enantioselective vinylcyclopropane‐cyclopentene rearrangement can be carried out on (vinylcyclopropyl)acetaldehydes through activation via enamine intermediates. The reaction makes use of racemic starting materials that, upon ring opening facilitated by the catalytic generation of a donor‐acceptor cyclopropane, deliver an acyclic iminium ion/dienolate intermediate in which all stereochemical information has been deleted. The final cyclization step forms the rearrangement product, showing that chirality transfer from the catalyst to the final compound is highly effective and leads to the stereocontrolled formation of a variety of structurally different cyclopentenes. [ABSTRACT FROM AUTHOR]

The asymmetric aza-Michael reaction of metal benzylamides to alpha,beta-unsaturated amides derived from the chiral amino alcohol (S,S)-(+)-pseudoephedrine is studied. The adducts obtained in the asymmetric aza-Michael reaction have proven to be very versatile synthetic intermediates in the preparation of other interesting compounds such as beta-amino esters, gamma-amino alcohols, and beta-amino ketones in highly enantioenriched form.

Research has been conducted on the stereocontrolled aziridine ring-opening reactions with chiral enolates. The procedure developed for these reactions has lead to the gamma-aminoamide production in good yields.

Research describes a highly stereoselective methodology for aldol additions to obtain chiral nonracemic aldol products, which can be converted into 1,3-syn and 1,3-anti diols and chiral building blocks such as beta-hydroxy acids, esters, and ketones.

A study on the stereoselective synthesis of isoquinoline alkaloids presents a general enantioselective synthetic technique to derive 4-alkyl-3-aryl-1,2,3,4-tetrahydroisoquinolines starting from chiral 1,2-diarylethylamine precursors that were prepared from deoxybenzoins. The protocol developed is interesting from the perspective of synthesis as it factors in, among other things, the possibility of introducing any kind of alkyl chain at the 4-position of the isoquinoline core.

The compounds (3S)-3-aryltetrahydroisoquinoline and (1S,3S)-3-aryl-1-methyltetrahydroisoquinolines (3a-c) were efficiently synthesized through a Pictet-Spengler heterocyclization reaction of optically active (S)-1,2-diarylethylamines. An alternative route towards the synthesis of the epimeric derivative of 3a, tetrahydroisoquinoline, was also attained by a stereocontrolled ring opening strategy performed on the oxazolotetrahydroisoquinoline.

An efficient and easy protocol for performing 1,3-dipolar cycloaddition using azomethine ylides and acrolein is presented. The reaction catalyzed by d -proline allows the synthesis of C-3 unsubstituted pyrrolidines. The application of this methodology to the synthesis of an advanced intermediate in the preparation of a Hepatitis C virus inhibitor is presented. Final attempts to complete the synthesis of the target inhibitor results in the preparation of its C-4 epimer in good overall yield. [ABSTRACT FROM AUTHOR]

Research has been conducted on the Mannich reaction involving enolizable imine compounds. The use of these imines in converting the initial carbonyl substrate or azomethine reagent into a more reactive derivative is described.