Chemical Aspects of Human and Environmental Overload with Fluorine.

Over the last 100-120 years, due to the ever-increasing importance of fluorine-containing compounds in modern technology and daily life, the explosive development of the fluorochemical industry led to an enormous increase of emission of fluoride ions into the biosphere. This made it more and more important to understand the biological activities, metabolism, degradation, and possible environmental hazards of such substances. This comprehensive and critical review focuses on the effects of fluoride ions and organofluorine compounds (mainly pharmaceuticals and agrochemicals) on human health and the environment. To give a better overview, various connected topics are also discussed: reasons and trends of the advance of fluorine-containing pharmaceuticals and agrochemicals, metabolism of fluorinated drugs, withdrawn fluorinated drugs, natural sources of organic and inorganic fluorine compounds in the environment (including the biosphere), sources of fluoride intake, and finally biomarkers of fluoride exposure.

Palladium-Catalyzed Arylfluorination of Alkenes: A Powerful New Approach to Organofluorine Compounds.

Fluorine incorporation into organic molecules is often beneficial to their absorption, distribution, metabolism, and excretion (ADME) properties or bioactivity. As a consequence, organofluorine compounds have become quite common amongst drugs and agrochemicals, and their preparation is a highly important topic in both synthetic organic chemistry and pharmaceutical chemistry. One of the newly developed methods for accessing organofluorine compounds is Pd-catalyzed arylfluorination of alkenes. It is an olefin difunctionalization process that simultaneously introduces an aryl group and a fluorine atom into an alkene framework. This review provides a concise overview of this powerful and versatile method.

Synthesis of novel fluorinated building blocks via halofluorination and related reactions.

A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.

Alicyclic ß- and γ-Amino Acids: Useful Scaffolds for the Stereocontrolled Access to Amino Acid-Based Carbocyclic Nucleoside Analogs.

Stereocontrolled synthesis of some amino acid-based carbocyclic nucleoside analogs containing ring C=C bond has been performed on ß- and γ-lactam basis. Key steps were N-arylation of readily available ß- or γ-lactam-derived amino ester isomers and amino alcohols with 5-amino-4,6-dichloropyrimidine; ring closure of the formed adduct with HC(OMe)3 and nucleophilic displacement of chlorine with various N-nucleophiles in the resulting 6-chloropurine moiety.

Fluorination of some highly functionalized cycloalkanes: chemoselectivity and substrate dependence.

A study exploring the chemical behavior of some dihydroxylated ß-amino ester stereo- and regioisomers, derived from unsaturated cyclic ß-amino acids is described. The nucleophilic fluorinations involving hydroxy-fluorine exchange of some highly functionalized alicyclic diol derivatives have been carried out in view of selective fluorination, investigating substrate dependence, neighboring group assistance and chemodifferentiation.

A Stereocontrolled Protocol to Highly Functionalized Fluorinated Scaffolds through a Fluoride Opening of Oxiranes.

A novel selective and substrate-dependent synthetic protocol has been developed towards the synthesis of various fluorine-containing, highly functionalized cycloalkane derivatives. The method involves the stereoselective epoxidation of some unsaturated cyclic ß-amino acid derivatives as model compounds, followed by a regioselective fluoride opening of oxiranes under various conditions with Deoxofluor and XtalFluor-E reagents, thereby offering an insight into this new epoxide opening methodology with fluoride.