A5062301943- Geology and Paleoclimatology Research
- Archaeology and ancient environmental studies
- Isotope Analysis in Ecology
- Catalytic C–H Functionalization Methods
- Chemical Synthesis and Reactions
- Synthesis and Biological Evaluation
- Phenothiazines and Benzothiazines Synthesis and Activities
- Catalytic Cross-Coupling Reactions
- Sulfur-Based Synthesis Techniques
- Pleistocene-Era Hominins and Archaeology
- Nuclear Physics and Applications
- Coordination Chemistry and Organometallics
- Chemical synthesis and alkaloids
- Radiation Effects and Dosimetry
- earthquake and tectonic studies
- Chemical Reaction Mechanisms
- Historical and Cultural Archaeology Studies
- Asymmetric Synthesis and Catalysis
- Vanadium and Halogenation Chemistry
- Oxidative Organic Chemistry Reactions
- Karst Systems and Hydrogeology
- Educational and Organizational Development
- Bioactive Compounds and Antitumor Agents
- Cyclopropane Reaction Mechanisms
- Social Issues and Sustainability
Universidad de Granada
2020-2025
Centro Nacional de Investigación sobre la Evolución Humana
2013-2020
Universidad de Burgos
2007-2012
Universidad de Oviedo
2007
An efficient synthesis of thiophenes and benzo[b]thiophenes has been developed from easily available bromoenynes o-alkynylbromobenzene derivatives. This novel one-pot procedure involves a Pd-catalyzed C–S bond formation using hydrogen sulfide surrogate followed by heterocyclization reaction. Moreover, in situ functionalization with selected electrophiles further expands the potential this methodology to preparation corresponding highly substituted sulfur heterocycles.
Abstract Simple organic acids like 2,4‐dinitrobenzenesulfonic acid (DNBSA) catalyze the Ritter reaction of secondary benzylic alcohols giving rise to corresponding N ‐benzylacetamides in usually high yields. Reactions can be conducted without exclusion oxygen and need dry solvents. With tertiary α,α‐dimethylbenzylic a different pathway involving formal dimerization takes place under acid‐catalytic conditions used. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
An efficient and regioselective synthesis of 4- 7-alkoxyindoles has been developed from commercially available starting materials such as 3-halophenols 3-chloroanisole. Directed ortho-metalation followed by two palladium-catalyzed processes, a Sonogashira coupling tandem amination/cyclization reaction, allows the regiochemically pure 7-substituted indoles. This strategy successfully applied to preparation 2-[3-(2-amino-2-oxoacetyl)-1-benzyl-2-ethyl-1H-indol-4-yloxy]acetic acid (LY315920),...
An efficient synthesis of 3-halo-7-oxygen-functionalized benzo[b]thiophenes bearing different substituents at C-2 has been developed from N,N-diethyl O-3-halophenylcarbamates. The key steps are an ortho-lithiation reaction, which gives rise to 3-halo-2-sulfanylphenol derivatives, and a electrophilic cyclization. subsequent functionalization the prepared halobenzothiophenes allows access wide variety 2,3,7-regioselectively functionalized in good overall yields.
2,3-Dihaloanilines have been proved as useful starting materials for synthesizing 4-halo-1H-indoles. Subsequent or in situ functionalization of the prepared haloindoles allows access to a wide variety 2,4- 2,3,4-regioselectively functionalized indoles good overall yields. As no efficient synthetic routes 2,3-dihaloanilines described literature, different approaches preparation these 1,2,3-functionalized aromatic precursors are now presented. The most general one involves Smiles rearrangement...
A new granite-doped concrete block with 60 cm x dimensions has been built at CENIEH, Burgos, Spain, for dosimetry calibration and cross-referencing purposes. Independent evaluations of the block’s gamma dose rate using passive Al2O3:C dosimeters various field spectrometer (NaI) probes produce consistent results 1495 ± 51 μGy a-1 1514 43 (or 1537 19 a-1, depending on evaluation procedure employed), respectively. Bulk radioelement concentrations calculated from spectrometry Windows method are...
Coupling of o-iodoanilines with terminal alkynes under standard Sonogashira conditions, and further treatment NaOH conventional heating or microwave irradiation, afford 2-substituted indoles in usually high yields. Functionalities such as halides, nitro, cyano groups are tolerated the reaction conditions.
A new synthesis of 4-halo-1H-indoles has been developed from easily available 2,3-dihalophenol derivatives. The key steps are Smiles rearrangement and a one-pot or stepwise Sonogashira coupling/NaOH-mediated cyclization. Subsequent functionalization allows access to wide variety 2,4- 2,3,4-regioselectively functionalized indoles.
In the present work, we briefly assess potential of Bruker Digital Temperature control system for ESR dosimetry/dating purpose and try to quantify influence cavity temperature on signal Aluminum center. Our results also show that it is possible reach a consistent level repeatability in measurements with Variable Unit (VTU) system, not only terms intensities, but equivalent dose (DE) values. As expected, our strong Given dependence, recommended apply some corrections factors, especially when...
A series of hydrofluoric (HF) acid etching experiments were performed on several 50 to 300 µm (nominal sieve opening) quartz and feldspar samples, average thicknesses subsequently determined from weight loss estimates, following the approach Bell & Zimmerman (1978). Our results are consistent with previous studies confirm that both HF experimental conditions (etching time, concentration, agitation) nature/origin minerals have a significant effect rate magnitude. For samples considered in...
Journal Article ESR dosimetry of fossil enamel: some comments about measurement precision, long-term signal fading and dose–response curve fitting Get access M. Duval, Duval * 1Centro nacional de investigación sobre la evolución humana (CENIEH), Paseo Atapuerca s/n, Burgos 09002, Spain *Corresponding author: mathieu.duval@cenieh.es Search for other works by this author on: Oxford Academic PubMed Google Scholar V. Guilarte Moreno, Moreno R. Grün 2Research School Earth Sciences (RSES), The...
A new route to regioselectively dialkoxy-functionalized benzo[ b ]furan derivatives has been developed from 3-halo-2-iodoanisoles bearing an additional methoxy group, which have accessed through ortho -zincation/iodination reaction. Two palladium-catalyzed processes, namely a Sonogashira coupling followed by tandem hydroxylation/cyclization sequence, give rise and interesting dimethoxy-substituted ]furans.
The potential of Q-band Electron Spin Resonance (ESR) for quantitative measurements has been scarcely evaluated in the literature and its application dose reconstruction fossil tooth enamel with dating purposes remains still quite unknown. Hence, we have performed a comparative study based on several Early to Middle Pleistocene samples using both X- spectroscopies. Our results show that offers significant improvement terms sensitivity signal resolution: it allows not only work reduced...