5 research outputs found
Catalytic enantioselective nucleophilic desymmetrization of phosphonate esters
Molecules that contain a stereogenic phosphorus atom are crucial to medicine, agrochemistry and catalysis. While methods are available for the selective construction of various chiral organophosphorus compounds, catalytic enantioselective approaches for their synthesis are far less common. Given the vastness of possible substituent combinations around a phosphorus atom, protocols for their preparation should also be divergent, providing facile access not only to one but to many classes of phosphorus compounds. Here we introduce a catalytic and enantioselective strategy for the preparation of an enantioenriched phosphorus(V) centre that can be diversified enantiospecifically to a wide range of biologically relevant phosphorus(V) compounds. The process, which involves an enantioselective nucleophilic substitution catalysed by a superbasic bifunctional iminophosphorane catalyst, can accommodate a wide range of carbon substituents at phosphorus. The resulting stable, yet versatile, synthetic intermediates can be combined with a multitude of medicinally relevant O-, N- and S-based nucleophiles
Effective transformation of household savings in the context of a systemic economic crisis
The modern world is characterized by a high degree of digitalization, so citizens have access to an increasing variety of savings options. In just a few clicks, people can purchase shares of the largest companies, invest in real estate rental funds, open deposits in almost any bank, and purchase digital assets. However, financial literacy has not yet reached the level needed to use all financial instruments consciously. Since confidence in the banking and financial system is low, people save in cash, which slows economic growth. The study of various forms of savings and their reliability and availability can increase cashflow from individuals, triggering growth, especially in the current crisis conditions of 2020–2022, with unprecedented sanctions. The purpose of the study is to develop recommendations for the development of modern forms of effective savings for the population under the conditions of a systemic economic crisis. The study uses publicly available data on personal savings rates and relevant scholarly literature and uses the methods of analysis and synthesis, comparison, deduction, and statistical generalizations. In the course of the study, key savings trends and urgent income issues were identified, allowing for the formulation of several recommendations to improve the efficiency of modern savings methods
Catalytic Enantioselective Nucleophilic Desymmetrisation of Phosphonate Esters
Compounds containing one or more stereogenic phosphorous atoms in the P(V) oxidation
state are important to chemistry, biology and medicine. These include marketed
antiviral drugs such as Tenofovir alafenamide and Remdesivir, an effective treatment
for Ebola which has also recently been approved for use against SARS-CoV-2 in the US.
Existing approaches for the stereoselective synthesis of P-stereogenic centers, while
elegant, remain mostly diastereoselective, with catalytic enantioselective approaches
being limited in application. Accordingly, conceptually novel, broad-scope, catalytic
strategies for the efficient stereoselective synthesis of diverse stereogenic P(V) containing
compounds remain essential.
To this end, we describe a novel enantioselective two-stage strategy, exploiting a catalytic and highly enantioselective desymmetrisation of phosphonate esters. Pivoting on the first stereocontrolled, sequential nucleophilic substitution of enantiotopic leaving groups from readily accessible pro-chiral P(V) precursors, a bifunctional iminophosphorane (BIMP) superbase catalyst was found to be essential in delivering reactive desymmetrised intermediates capable of downstream enantiospecific substitution. This uniquely modular, catalytic platform allows broad-scope, stereoselective access to a diverse library of chiral P(V) compounds including those with O, N and S-linkages
European vegetation archive (EVA). An integrated database of European vegetation plots
The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database