Α-phenyl Ketones Research Articles

Chiral isoxazolidine-mediated stereoselective umpolung α-phenylation of methyl ketones.

An effective asymmetric α-phenylation of methyl ketones with triphenylaluminium in the presence of (+)-benzopyranoisoxazolidine has been developed. The reaction proceeds via the in situ formation of a chiral N-alkoxyenamine and the subsequent diastereoselective nucleophilic phenylation to provide α-phenylated products in moderate to good yields, with high enantioselectivities.

Rhodium-catalyzed α-methylthiolation reaction of unactivated ketones using 1,2-diphenyl-2-methylthio-1-ethanone for the methylthio transfer reagent

In the presence of catalytic amounts of RhH(PPh 3) 4, 1,2-bis(diphenylphosphino)ethane (dppe), and dimethyl disulfide, ketones without α-activating groups were α-methylthiolated with 1,2-diphenyl-2-methylthio-1-ethanone giving α-methylthio ketones. The reaction of unsymmetrical ketones proceeded at the more substituted carbons. The initial formation of kinetic α-methylthiolated products followed by their rearrangement to thermodynamic products was observed in the reaction of α-phenyl ketones. Aldehydes, phenylacetate, and phenylacetonitrile were also α-methylthiolated under these conditions.

Copper-triethanolamine complex as efficient and active catalyst for selective oxidation of alkylarenes to phenyl ketones by tert-butylhydroperoxide

Several types of alkylarenes were selectively oxidized to the corresponding α-phenyl ketones in moderate to good selectivities and conversions using tert-butylhydroperoxide in the presence of a tetranuclear copper-triethanolamine complex under mild reaction conditions.

α-Phenylation of ketones via tin enolates catalysed by a palladium complex

The reaction of tributyltin enolates, prepared from tributyltin methoxide and enol acetates in situ, with bromobenzene in the presence of a catalytic amount of PdCl2(o-tolyl3P)2 was found to give α-phenyl ketones in good yields with essentially complete retetion of the acetate regiochemistry.

Condensations aryniques d'enolates de cetones—VI: Synthese de phenyl-2 cyclohexanones tricyclo[6,n,0,0 2,7]trienes-2,4,6 ols-1 diversement substitues

The condensation of benzyne in aprotic medium with the enolates of the 2,2,6-trimethyl, 3,3,5,5-tetramethyl, 4-4-dimethyl, 4-methyl, 4-t-butyl cyclohexanones as well as with those of α-tetralone and α-benzosuberone leads to the corresponding α-phenyl ketones and several tri and tetracyclic benzocyclobutenols.

Cyclopropanones and related compounds. Part II. Adducts from reduction of di-(α-bromobenzyl) ketone in the presence of dienes. Photolysis of α-phenyl ketones

Reduction of di-(α-bromobenzyl) ketone with sodium iodide in acetonitrile or acetone in the presence of cyclo-pentadiene yielded the interconvertible cis- and trans-isomers of 2,4-diphenylbicyclo[3,2,1]oct-6-en-3-one. The intermediate cyclopropanone or tautomer added to furan in the same way to form the corresponding 8-oxabicyclo[3,2,1]octanones, which on further treatment with acid isomerised to 1-(2-furyl)-1,3-diphenylpropan-2-one. The only adduct isolated from N-methylpyrrole was the corresponding pyrrolylpropanone. Thiophen and cyclohexa-1,3-diene did not form adducts. The same adducts were produced in lower yield by use of benzyl α-chlorobenzyl ketone and alkaline alumina, which is presumed to generate the same reactive intermediate. Pyrolysis of the furan cis-adduct gave stilbene, perhaps by reversal of its mode of formation, followed by loss of carbon monoxide from the 1,2-diphenylcyclopropanone. Stilbene was also formed by pyrolysis of benzyl α-acetoxybenzyl ketone by elimination of acetic acid and carbon monoxide. Ultraviolet irradiation of the carbocyclic bicyclo-octenones caused cis–trans isomerisation, succeeded by decarbonylation.

Quantitative Confirmation of the Cookson Rule for α-Phenyl Ketones

Quantitative Confirmation of the Cookson Rule for α-Phenyl Ketones

The Effect of Ring Formation on Optical Rotatory Power. A Comparison of the Optical Rotations of 2-Phenylcyclopentanone and of Some Acyclic α-Phenyl Ketones

The Effect of Ring Formation on Optical Rotatory Power. A Comparison of the Optical Rotations of 2-Phenylcyclopentanone and of Some Acyclic α-Phenyl Ketones