Acoplamientos arilo-alquino y alquino-alquino catalizados por Ni y Fe

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 21-06-201

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-catalysed cross-coupling of alkyl Grignard reagents and propargylic ammonium salts: Stereospecific synthesis of allenes

Herein we describe a robust and practical method to prepare enantiomerically enriched trisubstituted allenes using alkyl Grignard reagents and bench stable propargylic ammonium salts. Excellent yields as well as regio- and stereoselectivities are observed. Our conditions provide a solution to the allene racemization, which has been a long-standing problem when using Grignard reagents

Photostability and Dynamic Helical Behavior in Chiral Poly(phenylacetylene)s with a Preferred Screw-Sense

Data Availability Statement The data that support the findings of this study are available in the supplementary material of this article.Acknowledgements We thank Servicio de Microscopía Electrónica (RIAIDT, USC). Financial support from AEI (PID2019-109733GBI00), Ministerio de Ciencia e Innovación (PID2019- 107307RB-100 and PID2020-117605GB-100, PID2020- 113059GB-C21, PID2020-113059GB-C22). Xunta de Galicia (ED431C 2018/30, ED431C 2021/40, Centro Singular de Investigación de Galicia acreditación 2019–2022, ED431G 2019/03 and the European Regional Development Fund (ERDF) is gratefully acknowledged. F.R.T. thanks Xunta de Galicia for a predoctoral contract. We acknowledge CESGA for computational time and we also thank Servicio de Nanotecnología y Análisis de Superficies (CACTI-CINBIO, UVigo).Helical polymers such as poly(phenylacetylene)s (PPAs) are interesting materials due to the possibility of tuning their helical scaffold (sense and elongation) once they have been prepared and by the presence of external stimuli. The main limitation in the application of PPAs is their poor photostability. These polymers degrade under visible light exposure through a photochemical electrocyclization process. In this work, it was demonstrated, through a selected example, how the photochemical degradation in PPAs is directly related to their dynamic helical behavior. Thus, while PPAs with dynamic helical structures show poor photostability under UV/Vis light exposure, poly-(R)-1, bearing an enantiopure sulfoxide group as pendant group and designed to have a quasistatic helical behavior, shows a large photostability due to the restricted conformational composition at the polyene backbone, needed to orient the conjugated double bonds prior to the photochemical electrocyclization process and the subsequent degradation of the material.AEI (PID2019-109733GBI00)Ministerio de Ciencia e Innovación (PID2019- 107307RB-100 and PID2020-117605GB-100, PID2020- 113059GB-C21, PID2020-113059GB-C22)Xunta de Galicia (ED431C 2018/30, ED431C 2021/40, Centro Singular de Investigación de Galicia acreditación 2019–2022, ED431G 2019/03 and the European Regional Development Fund (ERDF

Copper-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes: Synthesis of cyclopropylboronates

This document is the accepted manuscript version of a Published Work that appeared in final form in Journal of American Chemical Society 136.45, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see DOI: 10.1021/ja510419zA novel Cu-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes to afford nonracemic cyclopropylboronates is described. Trapping the cyclopropylcopper intermediate with electrophilic amines allows for the synthesis of cyclopropylaminoboronic esters and demonstrates the potential of the approach for the synthesis of functionalized cyclopropanesWe 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

Turn-on Fluorescent Biosensors for Imaging Hypoxia-like Conditions in Living Cells

We present the synthesis, photophysical properties, and biological application of nontoxic 3-azo-conjugated BODIPY dyes as masked fluorescent biosensors of hypoxia-like conditions. The synthetic methodology is based on an operationally simple N=N bond-forming protocol, followed by a Suzuki coupling, that allows for a direct access to simple and underexplored 3-azo-substituted BODIPY. These dyes can turn on their emission properties under both chemical and biological reductive conditions, including bacterial and human azoreductases, which trigger the azo bond cleavage, leading to fluorescent 3-amino-BODIPY. We have also developed a practical enzymatic protocol, using an immobilized bacterial azoreductase that allows for the evaluation of these azo-based probes and can be used as a model for the less accessible and expensive human reductase NQO1. Quantum mechanical calculations uncover the restructuration of the topography of the S1 potential energy surface following the reduction of the azo moiety and rationalize the fluorescent quenching event through the mapping of an unprecedented pathway. Fluorescent microscopy experiments show that these azos can be used to visualize hypoxia-like conditions within living cellsThis article is dedicated to Professor M. Carmen Carreño on the occasion of her retirement. We thank MINECO (grant CTQ2017-85454-C2-2-P), MICINN (grant PID2020- 113059GB-C22), MCIU (grant PGC2018-094644-B-C21), the Ramón y Cajal Program (grant RYC-2016-20489), the Fundación La Caixa (grant no. LCF/BQ/DR19/11740024), and the Comunidad Autónoma de Madrid (B2017/BMD-3867 RENIMCM) and co-financed by the European Structural and investment fund for financial support. I.C. and F.R.-G. also acknowledge the Red Española de Supercomputación, the MareNostrum Supercomputer Center, and the Centro de Computación Científica of the UAM (CCC-UAM) for the generous allocation of computer time and for their technical support. We thank the “Servicio de Microscopía óptica y confocal CBMSO” facility for their assistance. We also thank Prof. M. C. Carreño for her advice and helpful discussions during the wor