Tribromomethyl ketone

While the haloform reaction normally only cleaves methyl ketones because of the structural requirements for the a,a,a-tribromomethyl ketone to induce fragmentation, the strain release that accompanies cleavage of a cyclobutanone permits extension... 

Acid-Catalyzed Enolization of an Aldehyde or Ketone in Aqueous Solution 899 Acid-Catalyzed Bromination of Acetone 901 Cleavage of a Tribromomethyl Ketone 903... 

Transbromination of ketones and activated aromatic compounds (phenols, naphthols, indole) by 4-(tribromomethyl)quinazoline is catalyzed by TFA245. Alkanes are brominat-ed by complexes of bromoform with aluminum tribromide (equation 33)246. 

With the presence of more than one halogen atom in the a-position of the halo ketone, the formation of 2-oxoalkylphosphonates becomes more difficult, and the reactions proceed exclusively according to the Perkow reaction. Thus, dichloromethyl, dibromomethyl, and tribromomethyl methyl ketones, in reaction with trialkyl phosphites, lead to the corresponding vinyl phosphates... 

The only sensible way to start is by addition of the main nucleophile present (hydroxide) to the carbonyl carbon of the ketone. The resulting tetrahedral intermediate can be taken in the direction of the product by eliminating a novel leaving group, a tribromomethyl carbanion ... 

Benzophenone p-Chlorobenzophenone 1-Hydroxycyclohexyl phenyl ketone 2-Hydroxy 2-methyl 1-phenyl 1-propanone photoinitiator, radiation-cured lacquers Anisoin Benzoin 2-Hydroxy 2-methyl 1-phenyl 1-propanone p-Phenylbenzophenone photoinitiator, resins o-Methyl benzoyl benzoate photoinitiator, resist inks Tribromomethyl phenylsulfone photoinitiator, screen inks... 

The cleavage of the carbon-carbon bond occurs by a two-step mechanism in which hydroxide ion attacks the carbonyl carbon atom to give a tetrahedral intermediate that subsequently releases the tribromomethyl carbanion. If iodine reacts with a methyl ketone, iodoform, CHI3, forms. It is a bright yellow, insoluble solid. 

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