Addition of fluonne and

Tnfluoromethyl hypofluonte will fluorinate Schiff bases, giving N,a,a-tn-fluoroatmnes and a-fluoroimines [144] and reacts with diazoketones to give adducts in modest yields [145] (equation 6) At-Substituted aziridines give nng opened products by 1,3 addition of fluonne on nitrogen and trifluoromethoxy on carbon [146] (equation 7)... 

The most widely used fluoroelastomers are copolymers of VDF and HFP and optionally also TFE. HFP interrupts the crystallimty of otherwise crystaUme PVDF TFE increases the fluonne content for mcreased solvent and heat resistance without raising the glass transition temperature as much as would an equivalent amount of additional HFP The dipolymer is random except that there are no contiguous HFP units and can therefore be represented as follows... 

Fluorination of naphthalene in a stream of dilute fluorine over cobalt trifluoride yields a mixture of perfluorodecalins and partially fluonnated naphthalene derivatives that are fully fluonnated to perfluorodecalins by a subsequent treatment with dilute fluonne [23] Perfluorodecalins are also final products ot fluorination of tetralin over cobalt trifluoride at 250 °C. A more thorough investigation of this reaction revealed seven additional compounds as products and intermediates [//] (equation 6). 

The effect of monofluorination on alkene or aromatic reactivity toward electrophiles is more difficult to predict Although a-fluonne stabilizes a carbocation relative to hydrogen, its opposing inductive effect makes olefins and aromatics more electron deficient. Fluorine therefore is activating only for electrophilic reactions with very late transition states where its resonance stabilization is maximized The faster rate of addition of trifluoroacetic acid and sulfuric acid to 2-fluoropropene vs propene is an example [775,116], but cases of such enhanced fluoroalkene reactivity in solution are quite rare [127] By contrast, there are many examples where the ortho-para-dueeting fluorine substituent is also activating in electrophilic aromatic substitutions [128]... 

Polymer-bound phenyliodine difluoride, which also has been used as a reagent to add fluorine to alkenes, can be prepared by the addition of xenon difluoride to the polymer [754, 755 136] Methyl iodide is converted to tnfluoro methyliodine difluoride by treatment with fluonne at -110 °C [757] Perfluoro-alkyliodine tetrafluondes could be synthesized from the perfluoroalkyliodine difluorides and fluorine [75S] or chlorine tnfluoride [759] Perfluoroalkyl [740] and perfluoroary 1 [747] iodides are oxidized to the corresponding iodine difluorides by chlorine trifluoride. 

Fluorme-containing Michael addition acceptors have been used as syntfaons, a portion of a molecule recognizably related to a simpler molecule, for the mtroduc-tion of fluonne into the organic molecules Their reactions with enamines and ketones lead to a condensadon-cyclizabon process... 

Hydrosilylations of fluonne-containing alkenes are free radical reactions initiated by UV light or organic peroxides The direction of addition is the same as with tluonnated alkyl halides However, the reaction between hydrosilanes and fluorine-containing olefins catalyzed by platinum group metal complexes may result in bidirectional addition and/or formation of a vinylic silane, the latter by de hydrogenative silylation[/] The natures of both the silane and the catalyst affect the outcome of the reaction[/] A random selection of some typical new reacUons of silanes are shown in Table 1 [1, 2, 3 4]... 

Fifolt [ 130] reported this chemical shift additivity method for fluorobenzenes in two deuterated solvents dg acetone and dg dimethyl sulfoxide (DMSO) Close correlations between expenraental and calculated fluonne chemical shifts were seen for 50 compounds Data presented in Thble 18 result from measurements in deuteiDchloroform as the solvent [56] Fluonne chemical shifts calculated by this additivity method can be used to predict approximate values for any substituted benzene with one or more fluonnes and any combination of the substituents, to differentiate structural isomers of multisubstituted fluorobenzenes [fluoromtrotoluenes (6, 7, and 8) in example 1, Table 19], and to assign chemical shifts of multiple fluonnes m the same compound [2,5 difluoroamlme (9) in example 2, Table 19] Calculated chemical shifts can be in error by more than 5 ppm (upfield) m some highly fluonnated systems, especially when one fluonne is ortho to two other fluonnes Shll, the calculated values can be informative even in these cases [2,3,4,6-tetrafluorobromobenzene (10) m example 3, Table 19]... 

The combination of a hydrogen fluoride addition and a chlorine-fluonne displacement converts 1,1 2,2-tetrachloroethylene-l,2 di(isocyanidedichloride)to perfluoro-A, A -dimethylethylenediamine [37] (equation 28)... 

In the [2+4] pencyclic cycloaddition reaction known as the Diels-Alder reaction, fluonne-containing compounds have been widely used as dienes, dieno-philes, or both Much of the fundamental work, including many comprehensive and systematic studies, was done before 1972, and Hudlicky provides an exeellent summary of this work [9] Additional sources for early work in this area are reviews in Organic Reactions [61] and Fluorine Chemistry Reviews [62]... 

P-Fluonne or fluonne further removed from the cation center always inductively destabilizes carbocabons [115, 116] No simple p-fluoroalkyl cations have been observed in either the gas phase or solution, and unhke the cases of the other halogens, there is no evidence for formation of alkyl fltioronium ions (5) in solution [117, 118], although (CH3)2F is long-hved m the gas phase [119] The only P-fluonnated cations observed in solution are those that benefit from additional conjugativc stabilization, such as a-trifluoromethylbenzyl cations [112] and per-fluonnated allyl [120], cydopropenium [112], and tropylium [121] ions... 

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