Fluorierung in späten Synthesestadien: extravagante Neuheit oder nützliches Hilfsmittel?

Abstract

Verzauberndes Fluor: Dieser Essay schildert die jüngsten Erfolge bei Fluorierungen im späten Synthesestadium und identifiziert die noch zu nehmenden Hürden zur Etablierung solcher Methoden in der Synthese komplexer Organofluoride. Ansätze werden beschrieben, wie ein vermehrtes Verständnis der Bindungswechselwirkungen des Fluors zu einer neuen Klasse milder und vielseitiger Fluorierungsreagentien führen könnte.

Consecutive C–F bond activation and C–F bond formation of heteroaromatics at rhodium: the peculiar role of FSi(OEt)3

“… 1 Therefore, there is a strong demand to access new fluorinated building blocks, but there is also enormous interest regarding their reactivity. Transition-metal-mediated routes to fluoroorganics often involve fluorination of non-fluorinated precursors 2 or selective C–F bond cleavage reactions at highly fluorinated molecules. 3 The latter approach frequently comprises the formation of metalated fluorinated entities, which can then be functionalized in the coordination sphere of the transition metal via very sophisticated reaction pathways.…”

SelectfluorTM on a PolyHIPE Material as Regenerative and Reusable Polymer‐Supported Electrophilic Fluorinating Agent

“…Indeed, the chemical positioning of a fluorine atom, which possesses a strong electron‐withdrawing ability and a relatively small size, often leads to stunning changes in the physical, chemical and biological properties of fluorinated compounds when compared with their non‐fluorinated analogues . From a synthetic point of view, the direct and selective electrophilic fluorination of organic compounds was made possible thanks to a collection of various fluorinating agents . In the early stages, sources of positive fluorine were designed featuring the O–F moiety (fluoroxyperfluoroalkanes R f OF, perfluoroacyl hypofluorites R f COOF, and sulfonyl hypofluorites R f SO 2 OF) but their explosive nature caused their rapid phase‐out .…”

A Versatile Organocatalytic Approach for the Synthesis of Enantioenriched gem‐Difluorinated Compounds

“…The versatile and chameleonic nature of the 1,3benzodithiol group allows useful alkylation chemistry,b efore it is transformed into the desired difluoroc ompound in al ater stage of the synthesis. [14] Results and Discussion Dithioacetals derived from aldehydes and ketones can be converted into the corresponding gem-difluoro compounds by ar eaction called oxidative desulfurization/fluorination. [15] Quite recently,w ed eveloped ah ighly stereoselective a-alkylation of aldehydes with commerciallya vailableb enzodithiolylium tetrafluoroborate.…”