Eloisa Serrano

Dynamic Kinetic Asymmetric [3+2] Annulation Reactions of Aminocyclopropanes

We report the first example of a dynamic kinetic asymmetric [3 + 2] annulation reaction of aminocyclopropanes with both enol ethers and aldehydes. Using a Cu catalyst and a commercially available bisoxazoline ligand, cyclopentyl- and tetrahydrofurylamines were obtained in 69-99% yield and up to a 98:2 enantiomeric ratio using the same reaction conditions. The method gives access to important enantio-enriched nitrogen building blocks for the synthesis of bioactive compounds.

Synthesis of (Carbo) nucleoside Analogues by [3+2] Annulation of Aminocyclopropanes

(Carbo)nucleoside derivatives constitute an important class of pharmaceuticals, yet there are only few convergent methods to access new analogues. Here, we report the first synthesis of thymine-, uracil-, and 5-fluorouracil-substituted diester donor-acceptor cyclopropanes and their use in the indium- and tin-catalyzed [3+2] annulations with aldehydes, ketones, and enol ethers. The obtained diester products could be easily decarboxylated and reduced to the corresponding alcohols. The method gives access to a broad range of new (carbo)nucleoside analogues in only four or five steps and will be highly useful for the synthesis of libraries of bioactive compounds.

Ni- and Fe-catalyzed Carboxylation of Unsaturated Hydrocarbons with CO2

The sustainable utilization of available feedstock materials for preparing valuable compounds holds great promise to revolutionize approaches in organic synthesis. In this regard, the implementation of abundant and inexpensive carbon dioxide (CO2) as a C1 building block has recently attracted considerable attention. Among the different alternatives in CO2 fixation, the preparation of carboxylic acids, relevant motifs in pharmaceuticals and agrochemicals, is particularly appealing, thus providing a rapid and unconventional entry to building blocks that are typically prepared via waste-producing protocols. While significant advances have been realized, the utilization of simple unsaturated hydrocarbons as coupling partners in carboxylation events is undoubtedly of utmost academic and industrial relevance, as two available feedstock materials can be combined in a catalytic fashion. This review article aims to describe the main achievements on the direct carboxylation of unsaturated hydrocarbons with CO2 by using cheap and available Ni or Fe catalytic species.

Nickel-Catalyzed Reductive Amidation of Unactivated Alkyl Bromides

A user-friendly, nickel-catalyzed reductive amidation of unactivated primary, secondary, and tertiary alkyl bromides with isocyanates is described. This catalytic strategy offers an efficient synthesis of a wide range of aliphatic amides under mild conditions and with an excellent chemoselectivity profile while avoiding the use of stoichiometric and sensitive organometallic reagents.

Taming hypervalent bonds and strained rings for catalysis and synthesis.

Improving the synthesis of complex organic molecules is essential for progress in many fields such as medicine, agrochemicals or materials. Since 2007, our laboratory has been focusing on the development of non-classical bond disconnections based on the use of small, energy-loaded organic molecules: hypervalent iodine reagents and strained rings. In this overview article, we report our progress since 2011 in these areas. The use of cyclic hypervalent iodine reagents has been extended to the C2-selective alkynylation of indoles, the domino cyclization alkynylation of allenes, the alkynylation of thiols and the azidation of carbonyl compounds. Amino-substituted aminocyclopropanes and aminocyclobutanes were used in [3+2] and [4+2] annulations to access nitrogen-rich building blocks, including nucleoside analogues. The first example of dynamic kinetic [3+2] annulation of aminocyclopropanes with both enol ethers and aldehydes was also reported.