Substitution ferrate complex

Similarly, the reaction of 3-halo-1-alkenes with tetrabutylammonium tricarbonyl-(nitrosyl)ferrate (TBAFe) gives T -allyl(tricarbonyl)(nitrosyl)iron complexes. Treatment of Y-bromo-a,p-unsaturated esters or amides with potassium tricarbonyl-(nitrosyl)ferrate provides planar chiral T] -allyl(dicarbonyl)(nitrosyl)iron complexes. Enantiopure amides as starting materials lead to a low diastereoselectivity, whereas no diastereoselectivity is observed for the chiral esters. The diastereoisomers of the amide-substituted allyliron complexes can be conveniently separated by column chromatography (Scheme 4-80). ... 

Simple ABO compounds in addition to BaTiO are cadmium titanate [12014-14-17, CdTiO lead titanate [12060-00-3] PbTiO potassium niobate [12030-85-2] KNbO sodium niobate [12034-09-2], NaNbO silver niobate [12309-96-5], AgNbO potassium iodate [7758-05-6], KIO bismuth ferrate [12010-42-3], BiFeO sodium tantalate, NaTaO and lead zirconate [12060-01 -4], PbZrO. The perovskite stmcture is also tolerant of a very wide range of multiple cation substitution on both A and B sites. Thus many more complex compounds have been found (16,17), eg, (K 2 i/2) 3 ... 

Within the past 20 years, ferrates, i.e. anions possessing iron as the center atom, have found increasing application as nucleophilic complexes in substitution chemistry. In these reactions, the ferrate replaces the leaving group X in a first nucleophilic substitution event. A transfer of one ligand from the metal atom (i.e. a reductive elimination, path A, Scheme 7.2) or substitution of the metal atom via external attack of the nucleophile (path B) concludes this mechanistic scenario. However, the exact mechanism in ferrate-catalyzed nucleophilic substitutions is still under debate. Apart from the ionic mechanism, radical processes are also discussed in the literature. 

Complementary to the conjugate substitution reaction in which the nucleophile is transferred directly from the tetraalkyl ferrate to the allylic ligand, preformed low-valent Fe complexes can form reactive allyl-iron complexes via an SN2 -type mechanism (path C, Equations (7.8) and (7.9), Scheme 7.16], These complexes react with incoming nucleophiles and electrophiles in a substitution reaction. Depending on the nature ofthe iron complex employed in the reaction, either o- or Jt-allyl complexes are generated. 

Procedure 4.3 Preparation and Isolation of AA Substituted Pentacyano-ferrate(ll) Complexes, [Fe(CN)5(AA)]n and Infrared Analysis1,2... 

TABLE 4.4 Results Summary for CV Analysis of Substituted Pentacyano ferrate(II) Complexes, [Fe(CN)5(L)]M ... 

The suffix -ate at the end of the name of the complex signifies that it is an anion. If the complex is neutral or cationic, no suffix is used. The English stem is usually used for the metal, but where the naming of an anion is awkward, the Latin stem is substituted. Eor example, ferrate is used rather than ironate, and plumbate rather than leadate (Table 25-6). 

Few cases of r -cyclopropenyl decomplexation have been reported. Conversion of various substituted cyclopropenylium cations with sodium dicarbonyl(cyclopentadienyl)ferrate gives (T-bound cyclopropenyliron complexes 1 which were converted to (x-cyclopropenylium complexes 2 or were decomplexed with self-coupling to form dicyclopropenylium systems 3. ... 

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