highlight on the reactivity of phseznx

The first bench stable selenolates, PhSeZnHalides have been synthesized through a completely atom economy oxidative insertion of the elemental zinc on the commercially available PhSeHalides. These reagents showed the characteristic nucleophilic reactivity which will be reviewed in this report. All of the reactions were strongly accelerated when effected in water suspension. Alkyl, aryl, vinyl and acyl substitutions, ring-opening reactions of epoxides and aziridines and Michael type addition will be described including the role of the zinc in the control of the chemoselectivity and stereoselectivity

Reconsidering the Variscan Basement of Southern Tuscany (Inner Northern Apennines)

The Pre‐Mesozoic units exposed in the inner Northern Apennines mostly consist of Pennsylvanian‐Permian successions unconformably deposited on a continental crust consolidated at the end of the Variscan orogenic cycle (Silurian‐Carboniferous). In the inner Northern Apennines, exposures of this continental crust, Cambrian?‐Devonian in age, have been described in Northern Tuscany, Elba Island (Tuscan Archipelago) and, partly, in scattered and isolated outcrops of southern Tuscany. This paper reappraises the most significant succession (i.e., Risanguigno Formation) exposed in southern Tuscany and considered by most authors as part of the Variscan Basement. New stratigraphic and structural studies, coupled with analyses of the organic matter content, allow us to refine the age of the Risanguigno Fm and its geological setting and evolution. Based on the low diversification of palynoflora, the content of sporomorphs, the structural setting and the new field study, this formation is dated as late Tournaisian to Visean (Middle Mississippian) and is not affected by pre‐Alpine deformation. This conclusion, together with the already existing data, clearly indicate that no exposures of rocks involved in the Variscan orogenesis occur in southern Tuscany

HIF-1-Dependent Induction of β3 Adrenoceptor: Evidence from the Mouse Retina

A major player in the homeostatic response to hypoxia is the hypoxia-inducible factor (HIF)-1 that transactivates a number of genes involved in neovessel proliferation in response to low oxygen tension. In the retina, hypoxia overstimulates β-adrenoceptors (β-ARs) which play a key role in the formation of pathogenic blood vessels. Among β-ARs, β3-AR expression is increased in proliferating vessels in concomitance with increased levels of HIF-1α and vascular endothelial growth factor (VEGF). Whether, similarly to VEGF, hypoxia-induced β3-AR upregulation is driven by HIF-1 is still unknown. We used the mouse model of oxygen-induced retinopathy (OIR), an acknowledged model of retinal angiogenesis, to verify the hypothesis of β3-AR transcriptional regulation by HIF-1. Investigation of β3-AR regulation over OIR progression revealed that the expression profile of β3-AR depends on oxygen tension, similar to VEGF. The additional evidence that HIF-1α stabilization decouples β3-AR expression from oxygen levels further indicates that HIF-1 regulates the expression of the β3-AR gene in the retina. Bioinformatics predicted the presence of six HIF-1 binding sites (HBS #1-6) upstream and inside the mouse β3-AR gene. Among these, HBS #1 has been identified as the most suitable HBS for HIF-1 binding. Chromatin immunoprecipitation-qPCR demonstrated an effective binding of HIF-1 to HBS #1 indicating the existence of a physical interaction between HIF-1 and the β3-AR gene. The additional finding that β3-AR gene expression is concomitantly activated indicates the possibility that HIF-1 transactivates the β3-AR gene. Our results are indicative of β3-AR involvement in HIF-1-mediated response to hypoxia

HIF-1-Dependent Induction of β3 Adrenoceptor: Evidence from the Mouse Retina

A major player in the homeostatic response to hypoxia is the hypoxia-inducible factor (HIF)-1 that transactivates a number of genes involved in neovessel proliferation in response to low oxygen tension. In the retina, hypoxia overstimulates β-adrenoceptors (β-ARs) which play a key role in the formation of pathogenic blood vessels. Among β-ARs, β3-AR expression is increased in proliferating vessels in concomitance with increased levels of HIF-1α and vascular endothelial growth factor (VEGF). Whether, similarly to VEGF, hypoxia-induced β3-AR upregulation is driven by HIF-1 is still unknown. We used the mouse model of oxygen-induced retinopathy (OIR), an acknowledged model of retinal angiogenesis, to verify the hypothesis of β3-AR transcriptional regulation by HIF-1. Investigation of β3-AR regulation over OIR progression revealed that the expression profile of β3-AR depends on oxygen tension, similar to VEGF. The additional evidence that HIF-1α stabilization decouples β3-AR expression from oxygen levels further indicates that HIF-1 regulates the expression of the β3-AR gene in the retina. Bioinformatics predicted the presence of six HIF-1 binding sites (HBS #1-6) upstream and inside the mouse β3-AR gene. Among these, HBS #1 has been identified as the most suitable HBS for HIF-1 binding. Chromatin immunoprecipitation-qPCR demonstrated an effective binding of HIF-1 to HBS #1 indicating the existence of a physical interaction between HIF-1 and the β3-AR gene. The additional finding that β3-AR gene expression is concomitantly activated indicates the possibility that HIF-1 transactivates the β3-AR gene. Our results are indicative of β3-AR involvement in HIF-1-mediated response to hypoxia

Solvent-free, uncatalyzed asymmetric “ene” reactions of N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines: a general approach to enantiomerically pure α-(trifluoromethyl)tryptamines

A novel approach to regioselectively substituted and stereoselectively α-trifluoromethylated tryptamines is reported based on the ene reaction of Boc-protected 3-methyleneindolines with optically pure (R)- or (S)-tert-butanesulfinyltrifluoroacetaldimine. Boc- and sulfinylamido-protected α-trifluoromethyltryptamines are obtained in 60–70% yield and 85/15 dr by just heating equimolar amounts of the two reaction partners at 80–90 °C for 2–3 h without a solvent. The absolute configuration of the amino α-carbon has been assigned based on the vibrational circular dichroism (VCD) spectral analysis. The two protecting group can be chemoselectively removed allowing further regio- and stereoselective elaboration of the ene products to various biologically interesting compounds

Sweet Selenium: Synthesis and Properties of Selenium-Containing Sugars and Derivatives

In the last decades, organoselenium compounds gained interest due to their important biological features. However, the lack of solubility, which characterizes most of them, makes their actual clinical exploitability a hard to reach goal. Selenosugars, with their intrinsic polarity, do not suffer from this issue and as a result, they can be conceived as a useful alternative. The aim of this review is to provide basic knowledge of the synthetic aspects of selenosugars, selenonium salts, selenoglycosides, and selenonucleotides. Their biological properties will be briefly detailed. Of course, it will not be a comprehensive dissertation but an analysis of what the authors think is the cream of the crop of this interesting research topic