Mitsunari Uno

A new route to phenylenedimalononitrile and the analogues using palladium-catalyzed carbon-carbon bond formation

Abstract Phenylenedimalononitrile and the analogues, which are key intermediates in the synthesis of TCNQ and the analogues, are prepared directly by the Pd-catalyzed reaction of-diiodoarenes with malononitrile anion.

Synthesis and structure of planar-chiral (1,2,4-trisubstituted cyclopentadienyl) cobalt(tetraarylcyclobutadiene) complexes containing three different chiralities in one molecule☆

Abstract The first diastereomerically pure planar-chiral cyclopentadienyl-cobalt complexes ( 4 and 5 ) have been synthesised by the reaction of CoCl(PPh 3 ) 3 with a trisubstituted cyclopentadienyl anion having a (−)-menthyl group in the presence of diarylacetylenes. Removal of the menthyl group from 4a and 5a afforded the first optically pure enantiomers of planar-chiral cyclopentadienylcobalt complexes, (+)- and (−)- 6 , and (+)- and (−)- 7 . The molecular structure including absolute configuration of 4a has been established by a single-crystal X-ray structure analysis. Crystallographic data for 4a : orthorhombic, space group P 2 1 2 1 2 1 ; a = 18.602(10), b = 15.629(3), c = 13.893(3) A; Z = 4; R = 0.051, R w = 0.057. The structure of 4a indicates that there exist three different chiralities [planar (Cp′-Co moiety), central ((−)-menthyl group), and helical (C 4 Ar 4 -moiety) chiralityl in one molecule. These complexes provide not only the first optically pure planar-chiral Cp′-Co complexes but also the first examples containing three different chiralities in one molecule.

Synthesis of planar-chiral cobalticinium complexes and their properties as chiral anion receptors

Abstract The first enantiomerically pure planar-chiral cobalticinium complexes have been synthesized and shown to behave as anion receptors which can recognize the chirality of camphor-10-sulfonate.

Synthesis of ruthenium complexes with planar-chiral cyclopentadienyl-pyridine or -phosphine bidentate ligands

Novel ruthenium complexes possessing planar-chiral cyclopentadienyl-pyridine or -phosphine bidentate ligands have been synthesized from (trisubstituted cyclopentadienyl)(benzene)ruthenium complexes. Co-ordination of the pyridyl group linked to a cyclopentadienyl ring through an ester bond is fairly weak, so that the pyridine dissociates from the central ruthenium atom in acetonitrile. In contrast, the phosphine ligand tightly co-ordinates to the ruthenium even in acetonitrile. Enantiomerically pure samples of planar-chiral cyclopentadienylphosphine complexes have been prepared by use of optically pure ruthenium complexes as a starting material. The molecular structure of a neutral ruthenium dithiocarbamate complex with the cyclopentadienylphosphine bidentate ligand has been determined by X-ray crystallography.

Synthesis and structure of planar-chiral cyclopentadienyl–cobalt(I) complexes: three different chiralities in one molecule

Diastereoisomerically pure planar-chiral cyclopentadienyl–cobalt complexes, 4 and 5, were prepared by the reaction of a trisubstituted cyclopentadiene bearing a (–)-menthyl group with [CoCl(PPh3)3] and acetylenes, and removal of the menthyl group from 4a and 5a afforded the optically pure enantiomers, (+)- and (–)-6, respectively; an X-ray structural analysis of 4a has revealed that there exist three different chiralities (planar, carbon-centred and helical) in one molecule.

A new method of synthesis of arylmalononitriles catalysed by a palladium complex

Arylmalononitriles are prepared in good yields using a palladium-catalysed coupling reaction between aryl halides and malononitrile.

Syntheses and x-ray crystal structures of neutral trans-bis(diamino-carbene)platinum(II) complexes

Abstract The first neural trans-bis(diamino-carbene)platinum(II) complex 2 is prepared by the reaction of trans-diiodo[bis(p-tolylisocyanide)]platinum(II)1 with a secondary amine, N,N-dipropylamine, while on applying a primary amine, N-propylamine, a neutral ortho-metalled trans-bis(diamino-carbene)platinum(II) complex 3 is obtained in good yield. The structures of carbene complexes 2 and 3 have been established by X-ray crystallography.

Synthesis of planar-chiral cobalticinium complexes

Abstract Planar-chiral cobalticinium complexes having a carboxylic function were synthesized in an enantiomerically pure form and transformed into several derivatives such as amide, ester and alcohol. The molecular structure including absolute configuration of 8b was established by a single-crystal X-ray structure analysis. Based on the configuration of the (−)-menthyl group, the absolute configuration of 8b around the CpM moiety was determined to be R .

Alkoxyperfluoroalkylation of enol ethers catalysed by iron complexes

The iron-catalysed coupling reaction of three components, perfluoroalkyl iodides, enol ethers and alcohols, in the presence of a base gives directly perfluoroalkyl-substituted acetals in good to excellent yields.

Induction of metal-centered chirality by planar chirality in[Fe{η-C5H2Me(R1)(CO2R2)}(COR)(CO)(PR3)] complexes

The reaction of planar-chiral (alkyl)(cyclopentadienyl)dicarbonyliron complexes with triphenylphosphine gives [Fe{η-C 5 H 2 Me(R 1 )(CO 2 R 2 )}(CO)(COR)(PPh 3 )] with a high diastereoselectivity (>90%) for the induction of metal-centered chirality.