Zwitterionic Acridinium Amidate: A Nitrogen-Centered Radical Catalyst for Photoinduced Direct Hydrogen Atom Transfer.

The development of small organic molecules that can convert light energy into chemical energy to directly promote molecular transformation is of fundamental importance in chemical science. Herein, we report a zwitterionic acridinium amidate as a catalyst for the direct functionalization of aliphatic C-H bonds. This organic zwitterion absorbs visible light to generate the corresponding amidyl radical in the form of excited-state triplet diradical with prominent reactivity for hydrogen atom transfer to facilitate C-H alkylation with a high turnover number. The experimental and theoretical investigations revealed that the noncovalent interactions between the anionic amidate nitrogen and a pertinent hydrogen-bond donor, such as hexafluoroisopropanol, are crucial for ensuring the efficient generation of catalytically active species, thereby fully eliciting the distinct reactivity of the acridinium amidate as a photoinduced direct hydrogen atom transfer catalyst.

Visible Light Thiyl Radical-Mediated Desilylation of Arylsilanes.

A straightforward, visible-light triggered desilylation of arylsilanes by thiyl radicals is presented. Silyl groups are often used to block a reactive position in multi-step organic synthesis, for which a mild cleavage at a late-stage will provide new possibilities and disconnection routes by CAr -Si cleavage/deprotection. In this work, commercially available and cheap disulfides are employed for the first time in this type of C(sp2 )-Si bond cleavage reactions. Thus, upon irradiation with visible-light, homolytic cleavage of the disulfide give rise to the corresponding thiyl radical that allows for a radical chain mechanism. This methodology represents a mild, fast and simple approach suitable for a broad variety of simply substituted arylsilanes. Moreover, the procedure could be easily extended to natural products and therapeutic derivatives, showing its robustness and synthetic application potential.

Halides as versatile anions in asymmetric anion-binding organocatalysis.

This review intends to provide an overview on the role of halide anions in the development of the research area of asymmetric anion-binding organocatalysis. Key early elucidation studies with chloride as counter-anion confirmed this type of alternative activation, which was then exploited in several processes and contributed to the advance and consolidation of anion-binding catalysis as a field. Thus, the use of the halide in the catalyst-anion complex as both a mere counter-anion spectator or an active nucleophile has been depicted, along with the new trends toward additional noncovalent contacts within the HB-donor catalyst and supramolecular interactions to both the anion and the cationic reactive species.

Clinicopathologic features and prognostic significance of CD30 expression in de novo diffuse large B-cell lymphoma (DLBCL): results in a homogeneous series from a single institution.

Introduction: The present study evaluates CD30 expression by immunohistochemistry (IHQ) in 216 patients with de novo DLBCL.Methods: CD30 expression was assessed retrospectively in all cases by IHQ. More than >0% and >20% of CD30 expression in the malignant cells were used as a cut-off for positivity. Survival was analysed in 176 patients treated with R-CHOP/R-CHOP-like regimens.Results: CD30 expression >0% was found in 66 (31%) patients, and >20% in 41 (19%). Younger patients <60 years (p = 0.03), good performance status (p = 0.04), and non-GCB subtype (p = 0.004) correlated with CD30 expression. No significant differences were found in overall survival and progression-free survival (PFS), although there was a trend towards better PFS in CD30-positive patients (p = 0.07). Among 7 patients with Epstein-Barr virus (EBV)-positive-DLBCL, CD30 was expressed in 71%, and 2-year PFS significantly inferior compared with CD30-positive EBV-negative-DLBCL patients (p = 0.01).Conclusion: CD30 is expressed in 30% of DLBCL patients, in whom targeted therapy with an anti-CD30 monoclonal antibody could be explored. CD30 is expressed more frequently younger patients, with better performance status and in the non-GCB subtype and its expression trends towards a better PFS. No significant differences regarding characteristics at diagnosis or prognosis were found between groups with different cut-off for positivity.

Catalytic Enantioselective Reactions with (Benzo)Pyrylium Salts.

The use of (benzo)pyrylium salts as versatile synthetic building blocks has become an attractive platform for the preparation of valuable heterocyclic compounds. Besides other numerous direct applications of (benzo)pyryliums, the intrinsic electrophilic nature of these species or the dipole character of the related oxidopyrylium derivatives have been exploited towards the development of enantioselective transformations such as nucleophilic dearomatization and cycloaddition reactions. This review aims at providing an overview on the relevant catalytic enantioselective methodologies developed in the past years, which are presented considering the involved metal- and/or organic catalytic system, as well as the type of reaction.

Double Cu-Catalyzed Direct Csp3 -H Azidation/CuAAC Reaction: A Direct Approach towards Demanding Triazole Conjugates.

The first one-pot procedure for the double copper(I)-catalyzed oxidative Csp3 -H azidation-CuAAC process, implying unstable azide intermediates and easy-to-remove reagents under water-tolerant conditions, is presented. The combination of tert-butyl hydroperoxide as oxidant and TMSN3 as azide source for the C-H bond azidation, which produces harmless side-products such as tBuOH and H2 O, probed to be perfectly compatible with the following cycloaddition step. Highly demanding 1,2,3-triazoles could be then directly obtained in good overall yields by extraction or simple crystallization, thus avoiding chromatography purifications. The potential of this methodology, has also being highlighted by the successful reaction of alkynes presenting interesting complex biological moieties based for example on biotin, DNA base or cinchona alkaloid units.

8-Mercaptoquinoline as a Ligand for Enhancing the Photocatalytic Activity of Pt(II) Coordination Complexes: Reactions and Mechanistic Insights.

A family of quinoline-platinum(II) complexes as efficient photocatalysts is presented. Their key characteristic is their easy preparation by coordination of the readily available 8-hydroxy- or 8-thio-quinoline ligands, which are well known for their strong chelating ability to different metal ions. In the different photochemical transformations investigated, such as cross-dehydrogenative coupling, oxidation of arylboronic acids, and asymmetric alkylation of aldehydes, 8-mercaptoquinoline-Pt(II) complex proved to be the most general catalyst. Moreover, quenching experiments showed that, contrary to related methods reported in the literature, these complexes followed an oxidative quenching mechanism in all transformations studied. Besides, simulations performed with high-level ab initio methods of the complexes have helped to understand their photocatalytic activity.

1,2,3,-Triazole-Based Catalysts: From Metal- to Supramolecular Organic Catalysis.

1,2,3-Triazoles are unique heterocycles with intriguing physical properties that allow not only the coordination to metals, but also the establishment of supramolecular interactions based on their polarized C-H bonds. In this account, an extensive work of our group on the design and application of 1,2,3-triazole catalysts is covered. Initially, a family of BINOL triazoles (Click-BINOLs) was synthesized and employed in model test reactions in asymmetric metal catalysis such as the Ti-catalyzed addition of alkylzinc reagents to aldehydes. The evolution from the Click-BINOLs to a novel class of triazole-based anion-binding organocatalysts is further discussed. Consequently, these catalysts were successfully applied in alkylation reactions, as well as asymmetric dearomatizations of diverse N-heteroarenes.

Recent progress in mild Csp3-H bond dehydrogenative or (mono-) oxidative functionalization.

Over the past few years, the development of oxidative methodologies towards efficient and selective direct Csp3-H bond functionalization processes has attracted tremendous attention from synthetic chemists. However, only a little attention has been given to the key role of the nature of the oxidant. This review aims at providing a brief summary of the recent advances in mild and more benign oxidative Csp3-H bond functionalization reactions, which are classified according to the type of oxidation system employed.

Pd(OAc)2/Ph3P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles.

The palladium-catalyzed dimerization of isoprene is a practical approach of synthesizing monoterpenes. Though several highly selective methods have been reported, most of them still required pressure or costly ligands for attaining the active system and desired selectivity. Herein, we present a simple and economical procedure towards the tail-to-tail dimer using readily available Pd(OAc)2 and inexpensive triphenylphosphine as ligand. Furthermore, simple screw cap vials are employed, allowing carrying out the reaction at low pressure. In addition, the potential of the dimer as a chemical platform for the preparation of heterocyclic terpenes by subsequent (hetero)-Diels-Alder or [4 + 1]-cycloadditions with nitrenes is also depicted.

Asymmetric nucleophilic dearomatization of diazarenes by anion-binding catalysis.

The first anion-binding organocatalyzed enantioselective Reissert-type dearomatization of diazarenes has been developed. This reaction represents a synthetic challenge since diazarenes have various reactive sites. The use of a chiral tetrakistriazole as a C-H-based hydrogen-donor catalyst allowed the straightforward highly regio- and enantioselective synthesis of a variety of chiral diazaheterocycles.

Dehydrogenative TEMPO-Mediated Formation of Unstable Nitrones: Easy Access to N-Carbamoyl Isoxazolines.

N-carbamoyl nitrones represent an important class of reagents for the synthesis of a variety of natural and biologically active compounds. These compounds are generally converted into valuable 4-isoxazolines upon cyclization reaction with dipolarophiles. However, these types of N-protected nitrones are highly unstable, which limits their synthesis, storage and practical use, enforcing alternative lengthy or elaborated synthetic routes. In this work, a 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-mediated formal "dehydrogenation" of N-protected benzyl-, allyl- and alkyl-substituted hydroxylamines followed by in situ trapping of the generated unstable nitrones into N-carbamoyl 4-isoxazolines is presented. A plausible mechanism is also proposed, in which the dipolarophile shows an important assistant role in the generation of the active nitrone intermediate. This simple protocol avoids the problematic isolation of N-carbamoyl protected nitrones, providing new synthetic possibilities in isoxazoline chemistry.

Oxidative C-H bond functionalization and ring expansion with TMSCHN2 : a copper(I)-catalyzed approach to dibenzoxepines and dibenzoazepines.

Tricyclic dibenzoxepines and dibenzazepines are important therapeutic agents for the pharmaceutical industry and academic research. However, their syntheses are generally rather tedious, requiring several steps that involve a Wagner-Meerwein-type rearrangement under harsh conditions. Herein, we present the first copper(I)-catalyzed oxidative CH bond functionalization and ring expansion with TMSCHN2 to yield these important derivatives in a facile and straightforward way.

Chiral helical oligotriazoles: new class of anion-binding catalysts for the asymmetric dearomatization of electron-deficient N-heteroarenes.

Helical chirality and selective anion-binding processes are key strategies used in nature to promote highly enantioselective chemical reactions. Although enormous efforts have been made to develop simple helical chiral systems and thus open new possibilities in asymmetric catalysis and synthesis, the efficient use of synthetic oligo- and polymeric helical chiral catalysts is still very challenging and rather unusual. In this work, structural unique chiral oligotriazoles have been developed as C-H bond-based anion-binding catalysts for the asymmetric dearomatization of N-heteroarenes. These rotational flexible catalysts adopt a reinforced chiral helical conformation upon binding to a chloride anion, allowing high levels of chirality transfer via a close chiral anion-pair complex with a preformed ionic substrate. This methodology offers a straightforward and potent entry to the synthesis of chiral (bioactive)heterocycles with added synthetic value from simple and abundant heteroarenes.

Enantioselective vinylogous-Mukaiyama-type dearomatisation by anion-binding catalysis.

The first enantioselective vinylogous Mukaiyama-type dearomatisation of heteroarenes under anion-binding catalysis is presented. A recyclable tetrakistriazole catalyst was used for the enantiocontrol of the remote vinylogous active position of silyl dienol ethers. This approach provided chiral heterocycles bearing α,ß-unsaturated chains with complete regioselectivity and excellent enantioselectivities (up to 97.5 : 2.5 e.r.).

Frontiers in Halogen and Chalcogen-Bond Donor Organocatalysis.

Non-covalent molecular interactions on the basis of halogen and chalcogen bonding represent a promising, powerful catalytic activation mode. However, these "unusual" non-covalent interactions are typically employed in the solid state and scarcely exploited in catalysis. In recent years, an increased interest in halogen and chalcogen bonding has been awaken, as they provide profound characteristics that make them an appealing alternative to the well-explored hydrogen bonding. Being particularly relevant in the binding of "soft" substrates, the similar strength to hydrogen bonding interactions and its higher directionality allows for solution-phase applications with halogen and chalcogen bonding as the key interaction. In this mini-review, the special features, state-of-the-art and key examples of these so-called σ-hole interactions in the field of organocatalysis are presented.

Estudo longitudinal de famílias / Longitudinal study of families / Estudio longitudinal de familias

Introdução: O desenvolvimento da família é influenciado por diversos fatores de sua organização interna e de ordem ambiental, social, cultural, econômica e política. Em contexto de pobreza os riscos são maiores. Fatores de proteção, como boa organização familiar e rede social de apoio podem diminuir as consequências negativas da pobreza. São escassas as pesquisas longitudinais sobre vulnerabilidade e resiliência nas famílias. Objetivo: Este artigo descreve o desenvolvimento de três famílias ao longo de 15 anos, estudadas por meio de entrevistas em casa, parte de uma coorte populacional de um bairro de Porto Alegre (RS). Buscaram-se associações entre a qualidade das relações nessas famílias e sua saúde física e mental, especialmente a do filho, foco da pesquisa. Métodos: Selecionaram-se no arquivo da pesquisa as três primeiras famílias (do total de 148) das quais se tinham os resultados completos das cinco visitas realizadas aos quatro meses e aos dois, quatro, nove e 15 anos de um filho. Realizou-se análise qualitativa dos registros em busca de categorias para compreender a vida e as relações interpessoais nas famílias. O estudo foi realizado em conjunto por duas pesquisadoras, médicas especialistas em desenvolvimento humano. As categorias identificadas na análise e estudadas nas cinco etapas foram: configuração familiar, situação socioeconômica, situações traumáticas, saúde física, saúde relacional e mental, evolução cognitiva e escolar do filho. Resultados: As três famílias, todas de classe C, com filhos sem problemas de saúde física, tiveram evolução suficientemente boa, apesar de todas enfrentarem múltiplos problemas, inclusive separações e mortes precoces. A relação com o sistema de saúde e escola era boa e similar para as três. A jovem com menos problemas de saúde mental foi aquela que sofreu perdas mais importantes: morte dos pais. Tinha uma estrutura familiar multigeracional sólida desde a primeira infância, com relações interpessoais predominantemente colaborativas e amorosas. Conclusões: O artigo busca avançar na compreensão da resiliência nas famílias em situações de vulnerabilidade. Concluímos que essas três famílias, uma delas mais que as outras, foram suficientemente saudáveis na tarefa de educar seus filhos sem desenvolverem problemas mentais graves. Propomos que o bom desenvolvimento se associa com a adequação e amorosidade dos cuidados com a etapa do ciclo vital, mesmo enfrentando situações problemáticas. Essas qualidades precisam estar associadas à estabilidade socioeconômica básica e a bons serviços de saúde e escola.

Introduction: Family development is influenced by it's internal organization and environmental factors, socioeconomic, cultural and political. In poor contexts there are more risks to development. Protection factors like good family organization and social network may decrease the risks. Longitudinal research about vulnerability and resilience in families is scarse. Objective: This article describes the development of three families over 15 years through interviews at home. The families were part of a populational cohort of a neighborhood in Porto Alegre (RS). We looked for links between the quality of relationships and the physical and mental health of these families, especially of the child focus of the research. Methods: We selected in the research archives the first three families (of a total of 148) for which we had full results of the five interviews at four months and two, four, nine and fifteen years of a child. We did a qualitative analysis of the records looking for parameters to understand the life and interpersonal relationships of these families. This study was done by two researchers, both experts in Human Development. The categories identified in the analysis of the five phases were: family structure, socioeconomic situation, traumatic experiences, physical, mental and relational health and cognitive evolution of the child. Results: All three families belonged to economical class C. The children were in good physical health and had sufficiently good general development, having faced multiple problems, including parental separation and early parental death. The relationship with the health and school systems was good in all of them. The youth with less mental health problems was the one who suffered the heaviest loss: early death of both parents. Her family had strong multigenerational ties since her early days, with predominant collaborative and loving relationships. Conclusions: This article aims to contribute to the comprehension of resilience in families in the context of vulnerability. We can say that these three families were healthy enough in the task of bringing up children without any serious mental health problem. We suggest that healthy development is associated with loving interfamily relationships adequate to each phase of development, notwithstanding dramatic events. This needs to be supported by basic economic stability and adequate school and health systems.

Introducción: El desarrollo de la familia es influenciado por su organización interna y factores ambientales, sociales, culturales, económicos y políticos. En contextos pobres los riesgos son mayores. Factores de protección como buena organización familiar y red social de apoyo pueden disminuir las consecuencias negativas de la pobreza. Son pocas las investigaciones longitudinales de vulnerabilidad y resiliencia de las familias. Objetivo: Este artículo describe el estudio del desarrollo de tres familias a lo largo de 15 años, a través de entrevistas en domicilio, parte de una cohorte poblacional de un barrio de Porto Alegre (RS). Se buscaron correlaciones entre la calidad de las relaciones de esas familias y su salud física y mental, especialmente la del hijo foco de la investigación. Métodos: Fueron seleccionadas en el archivo de la investigación las tres primeras familias (de un total de 148) de las cuales se tenían los resultados completos de las cinco visitas realizadas, a los 4 meses, y a los 2, 4, 9, y 15 años de un hijo. Fue realizado un análisis cualitativo de los registros en busca de categorías para comprender la vida y las relaciones interpersonales en las familias. El estudio fue hecho en conjunto por dos investigadoras, médicas especialistas en desarrollo humano. Las categorías identificadas en el análisis y estudiadas en las cinco etapas fueron: configuración familiar, situación socioeconómica, situaciones traumáticas, salud física, salud relacional y mental, evolución cognitiva y escolar del hijo. Resultados: Las tres familias, todas de clase C, con hijos sin problemas de salud física, tuvieron evolución suficientemente buena, a pesar de que todas enfrentaron múltiples problemas, incluso separaciones y muertes precoces. La relación con el sistema de salud y escuela era buena y similar para las tres. La joven con menos problemas de salud mental fue aquella que sufrió las mayores pérdidas: muerte de los padres. Tenía una estructura familiar multigeneracional sólida desde la primera infancia, con relaciones interpersonales predominantemente colaborativas y amorosas. Conclusiones: El artículo pretende avanzar en la comprensión de la resiliencia en las familias en situaciones de vulnerabilidad. Concluimos que esas tres familias, una de ellas más que las otras, fueron suficientemente saludables en la tarea de educar a sus hijos sin que desarrollaran problemas mentales graves. Proponemos que el buen desarrollo se asocia con el amor y adecuación de los cuidados a la etapa del ciclo vital, aun enfrentando situaciones problemáticas. Esas calidades necesitan estar asociadas a la estabilidad socioeconómica básica y buenos servicios de salud y escuela.

Prevalencia y caracterización de las neoplasias malignas en personas viviendo con VIH en Colombia / Prevalence and characterization of cancer in people living with HIV in Colombia

INTRODUCCIÓN: En el síndrome de inmunodeficiencia adquirida las neoplasias han jugado un papel preponderante, y con el advenimiento del tratamiento antirretroviral (TAR), la infección por VIH se ha transformado en una enfermedad crónica, siendo los tumores malignos una causa importante de morbilidad y mortalidad. OBJETIVO: Describir las características demográficas, clínicas y de laboratorio de las personas que viven con VIH (PVVIH) y han sido diagnosticadas con cáncer en Colombia y comparar los grupos de neoplasias definitorias y no definitorias de Sida. MÉTODOS: Revisión multicéntrica retrospectiva, en la que se recolectó y analizó datos relacionados con la infección por VIH y de diagnóstico de cáncer y tipo. Incluyó PVVIH diagnosticadas con neoplasias malignas atendidas en 23 centros de atención de pacientes con VIH en 11 ciudades de Colombia desde 1986 hasta 2018. RESULTADOS: En 23.189 pacientes, se identificaron 650 casos de malignidad (prevalencia de 2,8 % [IC de 95%: 2,6-2,9]). La neoplasia definitoria de Sida (NDS) sigue siendo el tipo de cáncer prevalente (71,1%), las neoplasias malignas más frecuentes fueron sarcoma de Kaposi (n: 330; 50,8%), linfoma no Hodgkin (n: 110; 16,9%), cáncer de piel (n: 48; 7,4%) y linfoma de Hodgkin (n: 25; 3,8%). Los pacientes con NDS tenían más probabilidades de ser HSH y estar en un estadio CDC 3, un recuento de linfocitos T CD4 < 200/μL y una carga viral del VIH ≥ 50 copias/mL al momento del diagnóstico de malignidad. Las personas con neoplasias no definitorias de Sida (NNDS) eran significativamente mayores y tenían más probabilidades de ser fumadores. CONCLUSIONES: Estos hallazgos son relevantes considerando la creciente carga de cáncer en las PVVIH que envejecen y las causas cambiantes de morbilidad y mortalidad. La presentación tardía a la atención del VIH y el retraso en el inicio del TAR son probablemente factores que contribuyen al cambio más lento hacia NNDS en comparación con las regiones de altos ingresos donde hay un acceso más rápido y temprano al TAR. El conocimiento de las tendencias epidemiológicas actuales y el perfil del cáncer en las PVVIH es fundamental para mejorar los esfuerzos de prevención y tratamiento del cáncer en el contexto de la atención integral del VIH.

BACKGROUND: In the acquired immunodeficiency syndrome, neoplasms have played a preponderant role, and with the advent of antiretroviral treatment (ART), HIV has become a chronic disease, with malignant tumors being an important cause of morbidity and mortality. AIM: To describe the demographic, clinical, and laboratory characteristics of people living with HIV (PLHIV) who have been diagnosed with cancer in Colombia and to compare the groups of AIDS-defining (ADC) and non-AIDS-defining neoplasms (NADC). METHODS: Retrospective, multicenter study that included people living with HIV/AIDS (PLHIV) diagnosed with malignancies treated at 23 HIV care centers located in 11 Colombian cities from 1986 to 2018. Data related to HIV infection and cancer diagnosis were collected and analyzed. RESULTS: Among 23,189 patients, 650 malignancy cases were identified (prevalence of 2.8% [95% CI 2.6-2.9]). AIDS-defining neoplasm remains the most prevalent type of cancer (71.1%), The most frequent individual malignancies were Kaposi sarcoma (n: 330; 50.8%), non-Hodgkin lymphoma (n: 110; 16.9%), skin cancer (n: 48; 7.4%), and Hodgkin lymphoma (n: 25; 3.8%). Compared people with NADC, with ADC were more likely to be MSM and have a CDC HIV stage 3, CD4 T cell count < 200/μL, and HIV viral load ≥ 50 copies/mL at the time of malignancy diagnosis. PLHIV and with NADC were significantly older and were more likely to be smokers. CONCLUSIONS: These findings are relevant considering the increasing burden of cancer in the aging PLHIV and the changing causes of morbidity and mortality. Late presentation to HIV care and delayed ART initiation are likely factors contributing to the slower shift toward NADCs compared with high-income regions where access to ART is better. Knowledge of the current epidemiological trends and profile of cancer in PLWHA is critical to improve cancer prevention and treatment efforts in the context of comprehensive HIV care.

Synthesis of N-(1H)-tetrazole sulfoximines.

N-(1H)-Tetrazole sulfoximines are readily available by addition of sodium azide to the corresponding N-cyano derivatives in the presence of ZnBr2. The use of these N-(1H)-tetrazoles as intermediates in the synthesis of other N-heterocyclic sulfoximines is demonstrated.

Iodinane- and metal-free synthesis of N-cyano sulfilimines: novel and easy access of NH-sulfoximines.

The synthesis of N-cyanosulfilimines can readily be achieved by reaction of the corresponding sulfides with cyanogen amine in the presence of a base and NBS or I2 as halogenating agents. Oxidation followed by C-N bond cleavage affords synthetically useful NH-free sulfoximines.