Mitsuo Konishi

Chiral β-dimethylaminoalkylphosphines. Highly efficient ligands for a nickel complex catalyzed asymmetric grignard cross-coupling reaction

Chiral β-dimethylaminoalkylphosphines were prepared starting with amino acids, (S)-alanine, (S)-phenylalanine, (R)-phenylglycine, (S)-valine, and (R)-tert-leucine. The chiral phosphines were found to be highly efficient ligands for a nickel catalyzed asymmetric Grignard cross-coupling reaction (38∼94% optical yield).

Regio- and stereo-chemistry in allylation of aryl Grignard reagents catalyzed by phosphine-nickel and -palladium complexes

Abstract Nickel and palladium complexes with the 1,1′-bis(diphenylphosphino)ferrocene ligand effectively catalyze regioselective cross-coupling of allylic ethers such as 1- or 3-methyl-2-propenyl silyl ethers with aryl-Grignard reagents, where the nickel catalyst leads to carbon—carbon bond formation at the more substituted position while carbon–carbon bond formation occurs at the less substituted position in the case of the palladium catalyst. Allylation of cis- and trans-5-methyl-2-cyclohexenyl silyl ethers was found to proceed with inversion of configuration with both the nickel and palladium catalysts. The stoichiometric reaction of a (1-methyl-π-allyl)palladium complex with the phenyl-Grignard reagent in the presence of phosphine ligands was also studied. A mechanism involving formation of the π-allyl(aryl)ML2 intermediate is proposed.

Dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II): an effective catalyst for cross-coupling reaction of a secondary alkyl grignard reagent with organic halides

Abstract Dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) was found to be an effective catalyst for the cross-coupling reaction of sec -butylmagnesium chloride with bromobenzene, β-bromostyrene, and 2-bromopropene to give the corresponding sec -butyl derivatives in exceedingly high yields.

Regioselective allylation of a grignard reagent catalysed by phosphine–nickel and –palladium complexes

Nickel and palladium complexes of the 1,1′-bis(diphenylphosphino)ferrocene ligand effectively catalysed the regioselective cross-coupling of allylic ethers with phenylmagnesium bromide; use of the nickel catalyst leads to carbon–carbon bond formation giving the terminal alkene while the palladium catalyst gives the non-terminal alkene.

Cross-coupling reaction of secondary alkyl grignard reagents with allylic alcohols catalyzed by dichloro[1,1′-bis(diphenylphosphino)-ferrocene]palladium(II)

Abstract Dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) was found to catalyze the reaction of allylic alcohols with 2-octylmagnesium chloride and 1-phenylethylmagnesium chloride to give the corresponding cross-coupling products in high yields.

Chirality transfer from optically active allylsilanes to π-allylpalladium complexes

The reaction of lithium palladates with the optically active allylsilanes, (E)- and(Z)-1-phenyl-1-trimethylsilyl-but-2-ene and (E)-and (z)-1-phenyl-3-trimethylsilylbut-1-ene proceeds stereospecifically [anti attack of palladium(II) with respect to the leaving silyl group] to give optically active π-allylpalladium complexes containing the η3-(1-methyl-3-phenylallyl) group in high yields.

THERMAL AND PHOTOSENSITIZED DECOMPOSITION OF DIMERIC VALEROPHENONE PEROXIDE FORMED BY OZONATION OF VALEROPHENONE OXIME ETHER

Abstract— Ozonation of valerophenone oxime o‐methyl ether (4) produced a stereoisomeric mixture of crystalline dimeric valerophenone peroxides, 5a and 5b. N‐n‐butyl‐N‐methoxybenzamide (6) and N‐methoxy‐N‐phenylvaleramide (7) along with valerophenone (1). Thermolysis of the higher melting peroxide 5a at 170–180°C, where a chemiluminescence was visible from added perylene. gave 1 and butyl benzoate (8) in addition to small amounts of the Norrish Type 11 products of 1. i.e. acetophenone (2) and cis‐ and trans‐ 2‐methyl‐1‐phenylcyclobutanols. Biacetyl‐sensitized photolysis of 5a in benzene yielded 2 in much higher yield in addition to 1, 8, and biphenyl. These results suggest that the triplet excited state of 1 is formed by the decomposition of 1 in low yield in thermolysis and in much higher yield in sensitized photolysis. although some of the Type II products may not arise from the triplet valerophenone.