Molybdenum-Catalyzed Synthesis of Nitrogenated Polyheterocycles from Nitroarenes and Glycols with Reuse of Waste Reduction By-product

A novel domino reduction/imine formation/intramolecular cyclization/oxidation for the efficient synthesis of pyrrolo(indolo)[1,2-a]quinoxalines and pyrrolo(indolo)[3,2-c]-quinolines from readily available nitrobenzenes and glycols is reported. The process utilizes the carbonyl byproduct of the initial dioxomolybdenum(VI)-catalyzed reduction of nitroaromatics with glycols as a reagent for the imine generation. This method represents the first sustainable domino reaction for the preparation of biologically relevant heterocycles that internally incorporates the waste formed in the first step to the final product.Junta de Castilla y León and FEDER (BU076U16) and Ministerio de Economía y Competitividad (MINECO) (CTQ2015-70371-REDT and CTQ2016-75023- C2-1-P

An unprecedented use for glycerol: chemoselective reducing agent for sulfoxides

A new application for glycerol that expands its possibilities beyond a green solvent and a precursor of value-added products has been demonstrated. Simple, easily available, and environmentally friendly dioxomolybdenum( VI) complexes are highly efficient catalysts for the chemoselective sulfoxide deoxygenation with this biomass-derived chemical feedstock. Both refined glycerol and crude glycerin can be used, thus expanding the potential application of this reaction. Subsequent transformation of glycerol during this reductive process has also been investigatedMinisterio de Ciencia e Innovacion (MICINN), FEDER (CTQ2010-15358 and CTQ2009-09949/BQU), Junta de Castilla y Leon (BU021A09 and GR-172), MICINN ("Juan de la Cierva" and "Ramon y Cajal" contracts for P.G.-G. and M.A.F.-R.

Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties

A catalytic domino reduction–imine formation– intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, stepeconomical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.Junta de Castilla y León and FEDER (BU291P18 and BU049P20) and Ministerio de Economía y Competitividad (MINECO) and FEDER (CTQ2016-75023-C2-1P) for financial support. The project leading to these results has also received funding from “la Caixa” Foundation, under the agreement (LCF/PR/PR18/51130007) (CAIXA-UBU001). R.H.-R. thanks Ministerio de Educación for a FPU predoctoral contract. S.S P. thanks Junta de Castilla y León and FSE and FEDER for a postdoctoral contract

La interdisciplinariedad y el itinerario curricular elegido por el estudiante, ejes fundamentales para desarrollar competencias curriculares en Química

Póster presentado en: V Jornadas de Innovación Docente de la UBU, Burgos, 21-22 de octubre de 2010, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

Phyllosilicate-content influence on the spectroscopic properties and antioxidant capacity of Iberian Cretaceous clays

Kaolinite-rich Cretaceous clay sediment samples from Burgos (Spain) have been analyzed by elemental analysis, X-ray fluorescence, inductively coupled plasma mass spectrometry, X-ray diffraction and different spectroscopic techniques, as Fourier Transform Infrared, ultraviolet–visible and electron paramagnetic resonance. The clay sediment samples mainly contain quartz, muscovite and kaolinite. Different radicals, as A- and B-Centers in kaolinite and organic paramagnetic species, are detected. An illite/kaolinite FTIR band ratio parameter (IKB) is proposed to infer the illite/kaolinite proportion, which can be useful to graphically visualize the iron-substituted Al(III) sites. Studies of the activity as scavengers of DPPH and ABTS radicals show that samples with a larger amount of orthorhombic Fe(III) ions replacing Al(III) ions exhibit a higher antioxidant capacity.Consejería de Educación of Junta de Castilla y León BU022G18, Junta de Castilla y León and FEDER BU291P18 and BU049P20, Ministerio de Economía y Competitividad CTQ2016-75023-C2-1-P and Ministerio de Ciencia, Innovación y Universidades CTQ(QMC) RED2018-102471-T MultiMetDrugs Network (Spain