Para-quinone methide: A new player in asymmetric catalysis

This is the accepted version of the following article: Parra, A. and Tortosa, M. (2015), para-Quinone Methide: a New Player in Asymmetric Catalysis. ChemCatChem, 7: 1524–1526, which has been published in final form at http://dx.doi.org/10.1002/cctc.201500176. This article may be used for non-commercial purposes in accordance with the Wiley Self-Archiving Policy wiley.com/WileyCDA/Section/id- 820227.htmlWe thank the European Research Council (ERC-337776) for the financial support. M. T. and A. P. thank MICINN for RyC and JdC contracts, respectivel

Cyclopropyl and cyclobutylboronates and silanes: A stereo­selective approach

Chiral cyclopropyl- and cyclobutylboronic esters and -silanes have become attractive intermediates for the preparation of functionalized small rings. This review highlights the stereoselective methods developed for their preparation, including both diastereo- and enantio­selective approaches. 1 Introduction 2 Stereoselective Synthesis of Cyclopropyl- and Cyclobutylboronates and -silanes 2.1 Diastereoselective Synthesis of Cyclopropyl- and Cyclobutylboronates and -silanes 2.2 Asymmetric Synthesis of Cyclopropyl- and Cyclobutylboronates and -silanes 3 ConclusionsWe thank the European Research Council (ERC-337776) and MINECO (CTQ2016-78779-R) for financial support. M.T. thanks MICINN for a RyC contrac

Regio- and stereospecific copper-catalyzed substitution reaction of propargylic ammonium salts with aryl Grignard reagents

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in Journal of the American Chemical Society, copyright © American Chemical Society after peer review. To access the final edited and published work see http://doi.org/10.1021/jacs.7b05273We have developed a copper-catalyzed substitution reaction of propargylic ammonium salts with aryl Grignard reagents. The reaction is stereospecific and α-regioselective and proceeds with exceptional functional group tolerance. Conveniently, a stable, inexpensive, and commercially available copper salt is used and no added ligand is requiredWe thank the European Research Council (ERC-337776) and MINECO (CTQ2016-78779-R) for financial support. M.T. thanks MICINN for a RyC contrac

Copper-catalyzed enantioselective synthesis of β-Boron β-Amino Esters

In this report, the enantioselective, copper-catalyzed borylation of β-amidoacrylates is disclosed. A broad variety of biologically important α-aminoboronates has been prepared with consistently high levels of enantiocontrol using an inexpensive copper catalyst and a commercially available chiral ligand. The method can be applied to the synthesis of novel boron-containing dipeptides and hemiboronatesWe thank the European Research Council (ERC-337776), MINECO (CTQ2016-78779-R), National Science Foundation (1151092 and 1543699) for financial support. M. T. thanks MICINN for RyC contrac

Copper-catalyzed silylation of p-quinone methides: New entry to dibenzylic silanes

An efficient and general copper(i)-catalyzed silylation of p-quinone-methides is described. Non-symmetric dibenzylic silanes are obtained in high yields under mild reaction conditions. These compounds can be used as bench-stable benzylic carbanion precursorsWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957) for financial support. M. T. and A. P. thank MICINN for RyC and JdC contract

Regioselective monoborylation of spirocyclobutenes

We present a strategy for the synthesis of spirocyclic cyclobutanes with modulable exit vectors based on the regioselective monoborylation of spirocyclobutenes. Using an inexpensive copper salt and a commercially available bidentate phosphine, a broad variety of borylated spirocycles have been prepared with complete regiocontrol. The boryl moiety provides a synthetic handled for further functionalization, allowing access to a wide array of spirocyclic building blocks from a common intermediateWe thank the European Research Council (ERC-337776) and MINECO and MICIIN (CTQ2016-78779-R and PID2019-107380GB-I00 to M.T.; PID2019106184GB-I00 and RED2018-102387-T to I.F.) for financial support. L.N. thanks Comunidad de Madrid for a predoctoral fellowship. We acknowledge Dr. Josefina Perles (UAM) for X-ray structure análisi

Stereospecific synthesis of α-hydroxy-cyclopropylboronates from allylic epoxides

This is the peer reviewed version of the following article: Angewandte Chemie - International Edition 58.10 (2019): 3188-03192, which has been published in final form at https://doi.org/10.1002/anie.201812836. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsWe report a catalytic and stereospecific method for the preparation of enantioenriched α-hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively prepared. Functionalization of the carbon–boron bond provides access to different enantiomerically enriched trisubstituted cyclopropanes from a common intermediateWe thank the European Research Council (ERC-337776) and MINECO (CTQ2016-78779-R) for financial suppor

Enantioselective synthesis of cyclobutylboronates via a copper-catalyzed desymmetrization approach

This is the peer reviewed version of the following article: Guisán-Ceinos, M., Parra, A., Martín-Heras, V. and Tortosa, M. (2016), Enantioselective Synthesis of Cyclobutylboronates via a Copper-Catalyzed Desymmetrization Approach. Angew. Chem., which has been published in final form at http://dx.doi.org/10.1002/ange.201601976. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.In this report, the first catalytic enantioselective synthesis of cyclobutylboronates, using a chiral copper(I) complex, is disclosed. A broad variety of cyclobutanes have been prepared with consistently high levels of diastereo- and enantiocontrol. Moreover, this method constitutes the first report of an enantioselective desymmetrization of meso-cyclobutenes to prepare chiral cyclobutanesWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957) for financial support. M. T. and A. P. thank MICINN for RyC and JdC contract

Stereoselective traceless borylation–allenation of propargylic epoxides: dual role of the copper catalyst

This is the peer reviewed version of the following article: Chemistry: A European Journal 23.69 (2017): 17478 –17481, which has been published in final form at http://doi.org/10.1002/chem.201705019. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingChiral α-allenols are prepared with high diastereocontrol through an unprecedented and spontaneous β-oxygen elimination of an α-epoxy vinyl boronate. Stochiometric experiments and DFT calculations support a dual role of the copper catalyst, which orchestrates the hydroboration and the syn-elimination stepThe European ResearchCouncil (ERC-337776) and MINECO (CTQ2016-78779-R) for financial support M.T.thanks MICINNfor a RyC contrac

Harnessing the elusive 1,4-reduction of vinyl epoxides through copper catalysis

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acscatal.9b02005We present an efficient strategy for the formal 1,4-reduction of vinyl epoxides that does not require superstoichiometric amounts of a strong reductant. Using a readily available copper catalyst and a diboron compound, a wide variety of enantioenriched allylic alcohols have been prepared. Additionally, epoxyenynes have been reduced in a 1,4-manner to selectively afford skipped enynes or skipped dienes.We thank the European Research Council (ERC-337776) and MINECO (CTQ2016-78779-R) for financial suppor