Copper bis-acetylacetonate

The joint action of primary or secondary amines (aniline, allylamine, benzylamine, butylmethylamine, iV-mcthylglycine methyl ester etc.) and copper bis(acetylacetonate) on the thiophen ylide 258 leads to dimethyl aminomalonates 259 by a carbene insertion reaction294. 

Maki, A. H., McGarvey, B. R. (1958) Electron spin resonance of transition metal chelates. I. Copper bis-acetylacetonate. J. Chem. Phys. 29, 31. 

Copper(ll) acetylacetonate Copper, bis(2,4-pentanedionato-0,0 )- (9) (46369-53-3) Methyl diazoacetate Acetic acid, diazo-, methyl ester (8,9) (6832-16-2) Triethylammonium fluoride Triethylamine hydrofluoride (8) Elhanamine, N,N-diethyl-, hydrofluoride (9) (29585-72-6)... 

Ylides from R N2. This reagent is more effective than bis(acetylacetonate)-copper(II) (5, 244) for generation of carbenes from diazo compounds.2 The decomposition proceeds at a lower temperature, even at room temperature. The mild conditions are particularly useful in the preparation of heat-sensitive ylides, such as those of antimony, bismuth, and tellurium. 

It has been verified by electron-spin magnetic-resonance spectroscopy that for copper(II) bis-acetylacetonate26 in mole-percent solution in a crystal of palladium(IJ) bis-acetylacetonate and for copper (II) bis-salicylaldehyde-imine27 in mole-percent solution in a crystal of nickel(II) bis-salicylaldehyde-imine the four coplanar short bonds formed by the copper atom are largely covalent and the two long bonds have very little covalent character. 

Bis(acetylacetonate)zinc(II), 33 Carbon monoxide, 66 of nitrogen compounds Palladium(II) chloride-Copper(II) chloride, 235... 

With this method, highly basic conditions no longer exist, an amine-exchange reaction does not occur, and contamination with anions is avoided. An incidental asset is that the two metal derivatives involved usually have different colors, and the extent of reaction can be judged visually. An obvious disadvantage is that the equilibrium may be unfavorable, as was described for the attempted reaction of bis(4-imino-2-pentanonato)copper(II) and 4,4 -tri-methylenedinitrilo)di-2-pentanone [bis(acetylacetone)tri-methylenediimine]. For successful isolation of a pure product, the metal derivative must be the most insoluble species present often, this condition is met. 

Carbenic fragmentation is formally the reverse of addition of carbenes to the sulfur atom of the thiophene ring, and has been observed only with 2,5-dichlorothiophenium bis(alkoxycarbonyl)methylides (30). When 30 (R = CHj) is heated at 110°C in refluxing toluene in the presence of rhodium(II) acetate or copper(II) acetylacetonate, fragmentation of the ylid to 2,5-dichlorothiophene and the carbenoid occurs. The bis(methoxycarbonyl)-carbene has been trapped with alkenes to produce high yields of the cyclopropanated products (78CC641). Since the ylid is a stable crystalline solid with a long shelf life, it represents a convenient source of bis-(methoxycarbonyl)carbene. 

Carbene generation Alumina—Potassium hydroxide. Bis(tribromomethyl)mercury. Bis (trimethylsilyldichloromethyl)mercury. Bromotrifluoromethane. n-Butyllithium. Copper (II) acetylacetonate. Diazoacetaldehyde. Di-n-chloro-x-allyldipalladium. Dichloromethyl 2-chloroethyl ether. Dicyanodiazomethane. sym-Difluorotetrachloroacetone. Ethylene oxide. Methyl dichlorofluoroacetate. Methyllithium. Phenyl (trichloromethyl)mercury. Sodium chlorodifluoroacetate. Sodium trichloroacetate. Thallous ethoxide. / -Toluene-sulfonyl-hydrazine. 

Isomerization of Allylic Alcohols and Formation of 1-Halo-1-alkynes. Isomerization of primary and secondary allylic alcohols to tertiary isomers proceeds in CH2CI2 at 25 °C in the presence of a catalyst that is prepared in situ by activation of vanadyl bis(acetylacetonate) or Mo02(acac)2 with (1) (eq 3). On the other hand, terminal alkynes react with (1) in the presence of copper or zinc halides in THF at —15 °C to afford terminal 1-halo-1-alkynes in 40-85% yields. By the same method, 1-cyano-l-alkynes are obtained in 65% yield by use of copper cyanide. 

A report (18) by Djordjevis, Lewis, and Nyholm in 1959 that reaction of copper acetylacetonate with N204 afforded bis-(3-nitro-2,4-pentanediono)copper-(II) (V), spurred our early efforts in acetylacetonate chemistry. The nitro-chelate was thoroughly characterized. 

The unusual copper nitrate-acetic anhydride reagent reacted with acetyl-acetone itself to form bis-(3-nitro-2,4-pentanediono) copper(II) (V), the same compound prepared by Nyholm (18). A novel elaboration of this reaction was treatment of hydrated chromium (III) nitrate with acetylacetone in acetic anhydride to yield a mixture of mono- and dinitrochromiumacetylacetonate (XI and XII). 

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