Tetrakis trifluoroacetato

Tetrakis(trifluoroacetato)ditungsten(II) is a bright yellow, diamagnetic solid that is highly air sensitive. It is very soluble in diethyl ether, THF, toluene, and dichloromethane and moderately soluble in hexane. The 84.26 MHz 19F NMR spectrum (in C6D6) consists of a single sharp resonance at 5 — 70.1 versus CFC13(<5 0.0). Other spectroscopic data and physicochemical properties are reported in the literature.17... 

A screening of ruthenium(II) carboxylates and several ruthenium(II) chloride complexes has identified tetrakis(trifluoroacetato)diruthenium as an excellent catalyst for the cyclo-propanation of cyclooctene with ethyl diazoacetate (60°C, excess of alkene, 0.75 mol% of catalyst yield of ethyl bicyclo[6.1,0]nonane-9-carboxylate 99% endojexo 1.65)." With several other ruthenium(II) complexes, ring-opening metathesis polymerization of cyclooctene competes strongly with the cyclopropanation reaction. 

In a similar manner, transfer of oxocarbenes from a-diazo ketones to benzene mediated by tetrakis(trifluoroacetato)dirhodium(II) yields, in some cases, 7-(l-oxoalkyl)cyclohepta-l,3,5-trienes. These compounds undergo facile acid-catalyzed isomerization to benzyl ketones 36. In other cases, the latter products are formed directly under the conditions of the carbenoid reaction " for examples, see Houben-Weyl, Vol. E19b, pl313. 

Tetramethylpropane-diammonium tetrakis-(trifluoroacetato-O)phenyl-bismuthate... 

Tetramethylbutane-1,4-diammonium phenyl-tetrakis(trifluoroacetato-0)bismuthate Ph (O) (O)... 

C hHjBIF 1208-C7Fl2(>N202 l,3-Bis(dimethylammonio)-2-propanol tetrakis(trifluoroacetato-O)-phenylbismuthate N,N,N, )V -Tetramethylbutane-1,4-diammonium phenyltetrakis-(trifluoroacetato-O)bismuthate 6.5-55 ... 

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