Group 9 carbonyl fluoride derivatives

The study of Group 9 carbonyl fluoride derivatives in the +1 oxidation state has revolved solely around fluoro derivatives of Vaska s complex, [MF(CO)(PR.3)2] (M = Ir, Rh). The preparation of [MF(CO)(PPh3)2] was originally the outcome... 

This cyclization is a reaction developed by Mori, who carried out a series of investigations with tin reagent 33. Fluoride is a much more reactive anion for initiation than any of the other halides, although it often leads to decomposition of the starting materials. In the case of vinylic or aryl halogen compounds the iodides are easier to transform than the bromides, and chlorides are unrcactive. The carbonyl group can be derived from either an aldehyde or a ketone, and even esters are sufficiently electrophilic.22... 

In the carbonyl compounds FC(0)Y the C—F bond distances show a strong dependence on the substituent X and shorten from 136.2(2) pm in acetyl fluoride (Y = Me) to 131.6(1) pm carbonyl fluoride (Y = F). In formyl fluoride (Y = H) and carbonyl chloride fluoride (Y = Cl) the C—F bond lengths are intermediate. When CF2 groups are double-bonded to C, O, S or Se, the C—F bond distances are remarkably constant and range only from 131.5 to 131.9 pm. Such bond lengths, however, are shorter by ca 1.5 pm in compounds with C=N double bonds, such as methanimine or 2,3-diaza-l, 3-butadiene. In both compounds only mean values for the C—F bond distances can be derived from the ED experiments. Ab initio calculations for perfluoromethanimine predict that the C—F bond trans to N—F is longer by 0.4 pm than the cis bond. 

In the binding assay of the derivatives, it is shown that both fluoride 14 and chloride 15 [60] strongly bind to EP2 receptor. In contrast to chlorinated derivative 15, which also has some affinities to EP1 and EP4 receptors, the fluoride 14 showed any significant affinities to EP1, EP3, or EP4 receptors at 10 pM [59], From these results, it seems that )S-fluoride or )S-chloride can be substituted for the carbonyl group at C-9 of PGE structure, and the substitution by a fluorine atom is more suitable for binding selectively to the EP2 receptor. The fluorinated... 

Only a few qui nones react with sulfur tetrafluoride in the normal way by replacing each carbonyl group by two fluorine atoms. The examples are 9,10-anthraquinone (l),41 phenanthrene-9,10-quinone (2),100 and acenaphthoquinone and its substituted derivatives 3.101102 The reactions proceed at 150-300 C, preferably in the presence of anhydrous hydrogen fluoride. 

Perfluoro ketones and perfluoro a-diketones, with a trifluoromethyl group in the -position to the carbonyl, cyclize in the presence of antimony(V) fluoride to give furan derivatives, as reviewed by Krcspan and Petrov.4 Perfluoro(4-methylpentan-2-one) (1) rearranges to per-fluoro(2,4-dimethyltetrahydrofuran) (2) in 84% yield, when heated in the presence of anti-mony(V) fluoride.5... 

In perfluoro a-diketone 7, which lacks a trifluoromethyl group /i to the carbonyl in the 2-position. it is the carbonyl in the 3-position that participates in the cyclization to form per-fluoro(2-acctyltetrahydrofuran) (8), when 7 is heated at 150 C in the presence of antimony(V) fluoride.5 Perfluoro(2-methyltetrahydropyran-3-one) also rearranges to furan derivative 8 in high yield when heated at 100 C in the presence of antimony(V) fluoride for 20 hours.5... 

Carbonyl Addition Diethylzinc has been added to benzaldehyde at room temperature in the presence of an ephedra-derived chiral quat (8) to give optically active secondary alcohols, a case in which the chiral catalyst affords a much higher enantioselectivity in the solid state than in solution (47 to 48, Scheme 10.6) [30]. Asymmetric trifluoromethylation of aldehydes and ketones (49 to 50, Scheme 10.6 [31]) is accomplished with trifluoromethyl-trimethylsilane, catalyzed by a quaternary ammonium fluoride (3d). Catalyst 3d was first used by the Shioiri group for catalytic asymmetric aldol reactions from silyl enol ethers 51 or 54 (Scheme 10.6) [32]. Various other 1,2-carbonyl additions [33] and aldol reactions [34] have been reported. 

In general, examples of substitution of sodium and potassium in organometallic derivatives by fluorine are limited to the salts of active methylene compounds. Their fluori nation is achieved with perchloryl fluoride.58 s9 62 6 fluorine,60 N-F reagents.49 and xenon difluoride01 (Table 10). The fluorination of metal enolates is discussed under metal-assisted substitution oc to a carbonyl group (see Section 1.1.2.5.). 

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