7 research outputs found
Reacciones de cicloisomerización y alcoxiciclación de o-(Alquinil)estirenos y de 1,3-Dien-5-inos catalizadas por complejos de oro(I)
La catálisis homogénea con complejos de oro ha sufrido un desarrollo espectacular en los últimos años convirtiéndose en una herramienta muy útil para la síntesis de una gran variedad de estructuras complejas, que no son accesibles mediante metodologías convencionales. Esta tesis se ha centrado en el estudio de la reactividad de o-(alquinil)estirenos con diferentes patrones de sustitución, en presencia de complejos de oro(I) como catalizadores. Estas transformaciones han conducido a la síntesis de un rango de derivados de indenos, benzofluorenos, dihidroindeno[2,1-a]indenos y derivados de naftalenos. Por otro lado, también se ha estudiado la reactividad de 1,3-dien-5-inos, sustratos estructuralmente relacionados con los o-(alquinil)estirenos, lo que ha permitido el desarrollo de una síntesis de bencenos y ciclopentadienos altamente funcionalizados. Estos últimos productos se han sintetizado también empleando complejos de oro(I) que presentan ligandos quirales, conduciendo a la formación de ciclopentadienos enriquecidos enantioméricamente. Estos ciclopentadienos han sido utilizados, junto con diversos dienófilos en reacciones de cicloadición Diels‒Alder permitiendo la síntesis de cicloaductos funcionalizados con total diastereoselectividad y elevada enantioselectividad
Formal [4 + 1] Cycloadditions of β,β-Diaryl-Substituted ortho-(Alkynyl)styrenes through Gold(I)-Catalyzed Cycloisomerization Reactions
Gold(I)-catalyzed cycloisomerization of β,β-diaryl-o-(alkynyl)-
styrenes at 80 °C selectively yields dihydroindeno[2,1-a]indenes in a
transformation that encompasses a formal [4 + 1] cycloaddition and takes
place through a cascade 5-endo-cyclization−diene activation−iso-Nazarov
cyclization. In addition, by performing the reaction at 0 °C, the same
substrates exclusively give rise to benzofulvene derivatives, which have also been shown to be intermediates in the formation of
the tetracyclics.Junta de Castilla y León (BU237U13)
and Ministerio de Economıá y Competitividad (MINECO) and
FEDER (CTQ2013-48937-C2-1-P
Recent developments in sensing devices based on polymeric systems
This review is focused on the analysis of recent developments in the application of polymers in the detection and quantification of target species. The work begins with a description of the polymers that are employed as sensory materials, covering molecularly imprinted polymers or MIPs, hybrid polymers, acrylic polymers, conductive polymers, polymers with chiral motifs and also the use of polymeric arrays. After the description of the sensory polymers, the different target species which can be detected using sensory polymeric devices, including metallic cations and anionic species, gases, explosives, radionuclides and bacteria or the recent biomedical and biological applications is described. Finally, the sensory devices fabricated using smart polymers, including, for example, sensory devices based on Quartz Crystal Microbalances or the use of micro and nanoporous materials as substrates for sensory polymeric coatings is listed and reviewed. The work also details the different detection mechanisms based on the type of response of the sensory polymers, such as electrical, piezoelectric or fluorescence. In brief, the review details a review of the research work published in the last 10 years in this quickly evolving field, with special emphasis in the biomedical and biological applications, which have emerged recently raising great attention. To conclude, some perspectives and future challenges that must be overcome by this research field in the next years is exposed.FEDER (Fondo Europeo de Desarrollo Regional) and the Spanish Agencia Estatal de Investigación (AEI) (MAT2017-84501-R
Gold(I)-catalyzed 6-endo hydroxycyclization of 7-substituted-1,6-enynes
The cyclization of o-(alkynyl)-3-(methylbut-2-enyl)benzenes, 1,6-enynes having a condensed aromatic ring at C3–C4 positions, has
been studied under the catalysis of cationic gold(I) complexes. The selective 6-endo-dig mode of cyclization observed for the
7-substituted substrates in the presence of water or methanol giving rise to hydroxy(methoxy)-functionalized dihydronaphthalene
derivatives is highly remarkable in the context of the observed reaction pathways for the cycloisomerizations of 1,6-enynes bearing
a trisubstituted olefinMinisterio de Ciencia e Innovación (MICINN) and FEDER (CTQ2010-15358
Straightforward Synthesis of Dihydrobenzo[a]fluorenes through Au(I)-Catalyzed Formal [3 + 3] Cycloadditions
Dihydrobenzo[a]fluorene derivatives have been prepared by a formal intramolecular [3 + 3] cycloaddition of o-alkynylstyrenes bearing a secondary alkyl group at the β-position of the styrene moiety. The process, catalyzed by a cationic gold(I) complex, involves a 1,2-hydride migration as the key step. 6,11-Dihydro-5H-benzo[a]fluorenes could be obtained from the initially generated 6,6a-dihydro-5H-benzo[a]fluorenes by subsequent heating of the reaction mixture under gold(I) or Brønsted acid catalysis or directly by conducting the reactions at high temperatureMICINN and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) and Junta de Castilla y Leon (BU021A09 and GR-172) for financial support. A.M.S. thanks Junta de Castilla y Leon (Consejeria de Educacion) and Fondo Social Europeo for a PIRTU contract. M.A.R. thanks MEC for a "Young Foreign Researchers" contract (SB2009-0186). P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in
Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher.
To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.htm
Smart polymers in micro and nano sensory devices
The present review presents the most recent developments concerning the application of sensory polymers in the detection and quantification of different target species. We will firstly describe the main polymers that are being employed as sensory polymers, including, for example, conducting or acrylate-based polymers. In the second part of the review, we will briefly describe the different mechanisms of detection and the target species, such as metal cations and anions, explosives, and biological and biomedical substances. To conclude, we will describe the advancements in recent years concerning the fabrication of micro and nano sensory devices based on smart polymers, with a bibliographic revision of the research work published between 2005 and today, with special emphasis on research work presented since 2010. A final section exposing the perspectives and challenges of this interesting research line will end the present review article.FEDER (Fondo Europeo de DEsarrollo Regional), and both
the Spanish Ministerio de Economía, Industria y Competitividad (MAT2014-54137-R, MAT2017-84501-R) and the
Consejería de Educación–Junta de Castilla y León (BU061U16
Synthesis of Functionalized 1H-Indenes and Benzofulvenes through Iodocyclization of o-(Alkynyl)styrenes
A convenient method for the preparation of synthetically useful 3-
iodoindene derivatives has been developed. This protocol, based on the 5-endo
iodocyclization reaction of o-(alkynyl)styrenes, represents one of the scarce examples of
halocyclizations using olefins as nucleophilic counterparts and allows the synthesis of both
3-iodo-1H-indenes (from β-alkyl-β-alkyl/aryl-o-(alkynyl)styrenes) and 3-iodobenzofulvenes
(from β,β-diaryl-o-(alkynyl)styrenes) in good yields under mild reaction conditions.
In addition, related alkoxyiodocyclization processes are described, which are particularly
interesting in their intramolecular version because they allow the synthesis of
heteropolycyclic structures containing the indene core. Finally, the usefulness of the
prepared 3-iodoindenes has been demonstrated by the synthesis of several polysubstituted
indene derivatives through conventional palladium-catalyzed cross-coupling reactions and
iodine−lithium exchange processes.Ministerio de Economiá y
Competitividad (MINECO) and FEDER (CTQ2013-48937-
C2-1P) and Junta de Castilla y León (BU237U13 and
BU076U16