Rapid and safe continuous-flow Simmons-Smith Cyclopropanation using a Zn/Cu couple column

Flow chemistry has recently opened new chemistry windows thanks to the safer use of hazardous and sensitive reagents. Furthermore, flow procedures usually outperform their batch counterparts due to improved mass and heat transfer, offering a good opportunity for industrial application. Herein, a rapid Simmons-Smith cyclopropanation flow process is presented. Taking advantage of the in situ production of the zinc carbenoid species, several olefins bearing aromatic rings of different electronic nature, aliphatic chains or heterocycles were smoothly cyclopropanated with a residence time of just 15 minutes. In addition, industrial applicability of the protocol is assured thanks to a successful 12-mmol scale experiment, which represents a 3.59 grams per hour production of a selected example, and to the satisfactory synthesis of pharmaceutical drugss Financial support was provided by the Spanish Government (PID2021-122299NB I00, TED2021-130470B I00, TED2021- 129999B C32), ‘Comunidad de Madrid’, European Structural Funds (S2018/NMT-4367), proyectos sinérgicos I+D (Y2020/ NMT6469). J. L. N. thanks “Comunidad de Madrid” for his industrial doctorate fellowship (IND2019/AMB-17142

Imine-Based Covalent Organic Frameworks as Photocatalysts for Metal Free Oxidation Processes under Visible Light Conditions

Embargo de 12 meses tras la publicación exigido por la editorialPhotochemistry of extended polyimine COF structures with laminar, spherical and 3D architectures has been examined. We show that these materials, composed by undecorated phenyl rings and imine fragments, can act as photocatalyts in oxidative transformations, being the crystalline laminar material the most active photocatalyst. The sulfoxidation reaction proceeds with good yields for a large variety of different sulfides. This process was carried out under visible light conditions (20 W), ethanol/H2O as solvent, and the heterogeneous porous material can be recycled up to 9 times. The crystallinity favours the behavior as photocatalyst of laminar and spherical COFs whereas any particular effect on the 3D material activity was observed. Sulfoxidation reaction mainly proceeds through an energy transfer mechanism using crystalline laminar material. In addition, these materials as photocatalysts were used for the oxidation of phenyl boronic acid into phenolWe are grateful to the Spanish Government (CTQ2015- 64561-R and RTI2018-095038-B-I00), “Comunidad de Madrid” and European Structural Funds (S2018/NMT-4367). Leyre Marzo thanks to CAM for the Atracción de Talento fellowship (2/ 2017-T2/AMB-5037

Anchoring of 10-phenylphenothiazine to mesoporous silica materials: A water compatible organic photocatalyst for the degradation of pollutants

The application of organic photocatalysts towards the oxidation of pollutants in water is hampered by different limitations such as their insolubility in the media. Herein, we report that the grafting of a photo-organocatalyst into mesoporous silica materials is an ideal approach to obtain effective catalysts. Thereby, the photocatalyst 10-phenylphenothiazine (PTH) was easily anchored into three different mesoporous silica-based materials (MSN, MSU-2 and SBA-15) with different particle sizes and pore sizes through an amide bond formation. The materials were characterized using IR analysis, solid-state X-ray diffraction, porosity and microscopy (SEM and TEM) techniques, showing that PTH is immobilized inside the pores of the materials and its optical properties are maintained after the anchoring. Although homogeneous PTH was inactive in water media, the three photocatalytic materials were active for the degradation of pollutants. SBA-15-AP-PTH exhibited the highest catalytic performance towards the degradation of acetaminophen and diclofenac under solar irradiation, finding in this manner a new strategy for the decontamination of pollutantsThis work was financially supported by the European Research Council (ERC-CoG, No. 647550), Spanish Government (No. RTI2018- 095038-B-I00), and Spanish State Research Agency (No. PID2019-106186RB-I00/AEI/10.13039/ 501100011033

Design, Synthesis, Characterization, and Evaluation of the Anti-HT-29 Colorectal Cell Line Activity of Novel 8-Oxyquinolinate-Platinum(II)-Loaded Nanostructured Lipid Carriers Targeted with Riboflavin

Colorectal cancer is occasionally called colon or rectal cancer, depending on where cancer begins to form, and is the second leading cause of cancer death among both men and women. The platinum-based [PtCl(8-O-quinolinate)(dmso)] (8-QO-Pt) compound has demonstrated encouraging anticancer activity. Three different systems of 8-QO-Pt-encapsulated nanostructured lipid carriers (NLCs) with riboflavin (RFV) were investigated. NLCs of myristyl myristate were synthesized by ultrasonication in the presence of RFV. RFV-decorated nanoparticles displayed a spherical shape and a narrow size dispersion in the range of 144–175 nm mean particle diameter. The 8-QO-Pt-loaded formulations of NLC/RFV with more than 70% encapsulation efficiency showed sustained in vitro release for 24 h. Cytotoxicity, cell uptake, and apoptosis were evaluated in the HT-29 human colorectal adenocarcinoma cell line. The results revealed that 8-QO-Pt-loaded formulations of NLC/RFV showed higher cytotoxicity than the free 8-QO-Pt compound at 5.0 µM. All three systems exhibited different levels of cellular internalization. Moreover, the hemotoxicity assay showed the safety profile of the formulations (less than 3.7%). Taken together, RFV-targeted NLC systems for drug delivery have been investigated for the first time in our study and the results are promising for the future of chemotherapy in colon cancer treatmen

Ligandos fesulphos en catálisis asimétrica|bapertura enantioselectiva de alquenos heterobicíclicos y reacción 1,3-dipolar de iluros de azometino

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 21-04-200

Nuevos horizontes en aminocatálisis asimétrica

In this work, we exposed a brief report about the development of the asymmetric aminocatalysis by using secondary-amines such as the initial enantioselective aldol reactions, the iminium activation, or the last organocatalytic tandem and cascade reactions. These pioneer works have opened a new research area in asymmetric catalysis in which is possible to developed new synthetic tools. The asymmetric aminocatalysis is currently being applied to the synthesis of drugs or bioactive compounds (e.g. Tamiflu®).En este artículo se expone brevemente el desarrollo de la aminocatálisis asimétrica empleando aminas secundarias: desde las primeras reacciones aldólicas enantioselectivas, las brillantes activaciones tipo ión iminio, hasta las últimas reacciones tipo tándem y en cascada. Todos estos trabajos pioneros han establecido en esta nueva área un campo de investigación dentro de la catálisis, permitiendo el desarrollo de herramientas sintéticas potentes que ya están siendo aplicadas en la síntesis de distintos fármacos o productos bioactivos, como por ejemplo el Tamiflu®

Single walled carbon nanotubes with encapsulated Pt(II) photocatalyst for the oxidation of sulfides in water

A simple one-step synthesis of a heterogeneous photocatalyst based on the encapsulation of the quinolinate-platinum complex 1 in the inner cavity of Single Walled Carbon Nanotubes (Pt1@oSWNT) is presented. This strategy generates a robust and stable catalyst for photooxidations performed in water media. Pt1@oSWNT is characterized spectroscopically and microscopically to have encapsulated a 2.5 % wt. of the unaltered complex. This material, which only contained 0.04 mol% of 1, is able to chemoselectively yield a wide variety of sulfoxides in water in the presence of air under 385 nm irradiation. The catalyst also presents affinity for polyaromatic substrates, increasing the reaction rate as a function of the number of condensed rings, achieving turnover frequencies as high as 8187 h−1. Moreover, the heterogeneous catalyst could be recycled for more than six consecutive reaction runs without losing its catalytic activity or detecting catalyst leachingFinancial support was provided by the Spanish Government (RTI2018-095038-B-I00), ‘‘Comunidad de Madrid”, and European Structural Funds (S2018/NMT-4367) proyectos sinérgicos I + D (Y2020/NMT-6469) and ‘‘Comunidad de Madrid” (SI1/PJI/2019- 00237). M.B. thanks the Spanish Government for a Juan de la Cierva contract (IJC2019-042157-I