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Macrocyclic tetraimidazolium salts 3-PF6, 3-TFSI(TFSI = N(SO2CF3)2), and 4-PF6[3: 1,3-bis(imidazolyl)-2,4-Me2C6H2core; 4: 1,3-bis(imidazolyl)C6H4core] were synthesized. Treatment of 3-PF6and 3-TFSIwith AgOAc yielded tetranuclear [(NHC)2Ag]4complexes 5-PF6-A/Band 5-TFSI-A/Bhaving a boxlike structure, respectively, which contained structural isomers arising from staggered and eclipsed configurations of two macrocyclic ligands. The reaction of 5-TFSI-A/Bwith [RhCl(coe)2]2resulted in the formation of a mixture of dinuclear [(CCC-pincer)Rh]2complexes 6-TFSIand 7-TFSIwith the macrocyclic scaffold through transmetalation and cyclometalation. X-ray crystallographic analysis revealed the flexibility of the butylene linkers of 6-TFSIand 7-TFSI. In contrast, the reaction of 4-PF6with [RhCl(cod)]2led to the formation of dinuclear [(NHC)2Rh]2complexes as a mixture of structural isomers 8a-PF6and 8b-PF6, where the macrocyclic ligand acted as a bidentate NHC ligand for each Rh center.

Eine Prise genügt: Der 1/FeCl2‐Komplex katalysiert in Gegenwart von Zn die Hydrosilan‐Reduktion von Ketonen zu den S‐konfigurierten Alkoholen. Der Katalysator 1/Fe(OAc)2liefert dagegen das R‐Enantiomer. Auf diese Art sind beide Enantiomere mit einer einzigen Chiralitätsquelle durch Zugabe einer kleinen Menge Zn zugänglich.

Just a little bit: The 1/FeCl2complex was activated in the presence of Zn and exhibited catalytic activity for the hydrosilane reduction of ketones to give the S‐configured alcohol. In contrast, the mixed‐catalyst system of 1and Fe(OAc)2provides the Renantiomer. This approach provides both enantiomers from a single chiral source by the addition of a small amount of Zn.

Good to excellent enantioselectivities(up to 99 % ee) of trans‐cyclopropane derivatives were achieved in the cyclopropanation of alkenes with tert‐butyl α‐diazoacetate by using 0.5 mol % of a mononuclear chiral ruthenium aqua complex containing the chiral bis(oxazolinyl)phenyl ligand, which was obtained via CH activation by RuCl3⋅3 H2O in the presence of Mg and cyclooctadiene (cod). Intramolecular cyclopropanation reactions using the new Ru complex also proceed with high yields and excellent enantioselectivities.

Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.

Chiral bis(oxazolinyl)phenyl–rhodium acetate complex can enantioselectively capture 1,1′‐binaphthol derivatives by ligand‐exchange reaction. The structure of the bis(oxazolinyl)phenyl–rhodium biphenol and binaphthol complexes were confirmed by X‐ray analysis.

Thermolysis of the rhodium(III) complex [(dm-Phebox-dm)Rh(OAc)2(H2O)] [1; dm-Phebox-dm = 2,6-bis(4,4-dimethyloxazolinyl)phenyl] in various arenes results in the formation of the corresponding aryl complexes [(dm-Phebox-dm)Rh(Ar)(κ2-OAc)] [Ar = C6H5 (2), 3,5-Me2C6H3 (3), 3,4-Me2C6H3 (4), C6H4Me (5), C6H4CF3 (6), C6H4OMe (7), C6H4COMe (8), C6H4Cl (9)]. The reaction of 1 with monosubstituted benzenes such as toluene, anisole, acetophenone, trifluorotoluene, and chlorobenzene produces a mixture of meta- and para-activated complexes, the ratio of which depends on the substituents on the benzene ring. The relative rate of the reaction of 1 with monosubstituted benzenes C6H5X was determined to be: X = OMe (1.8) > COMe (1.6) > CF3 (1.2), Cl (1.2) > CH3 (1). The acetato ligand of 1 appears to be essential for C–H bond activation of arenes as no reaction of the RhIII complex [(dm-Phebox-dm)RhCl2(H2O)] is observed in chlorobenzene at 120 °C. The first-order rate constants obtained by thermolysis of 1 in [D8]toluene at 97.1–116.5 °C yielded the following activation parameters: ΔH‡ = 22(2) kcal mol–1, ΔS‡ = –24(5) cal mol–1 K–1. The kinetic isotope effect for the C–H bond activation of toluene by 1 was determined to be kH/kD = 5.4 at 100 °C. These data suggest that the rate-determining step involves the C–H bond cleavage with a rigid, cyclic transition structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A series of ruthenium complexes with chiral phosphane ligands (Ru2Cl4[(–)-DIOP]3 (1), Ru(Ind)Cl[(–)-DIOP] (2), and Ru(Cp*)Cl[(–)-DIOP] (3), DIOP = 2,3-(isopropylidenedioxy)-2,3-dihydroxy-l,4-bis(diphenylphosphanyl)butane) were synthesized, characterized by X-ray crystallography, and employed in asymmetric halogen transfer radical addition and metal-catalyzed living radical polymerization reactions of olefins, such as styrene, methyl acrylate (MA), and methyl methacrylate (MMA). X-ray crystallographic analysis revealed the binuclear structure of 1 and the mononuclear structures of 2 and 3, which suggests that the chiral environments are established around the ruthenium center. Complexes 1 and 2 induced asymmetry in chiral addition reactions with high chemical yield and relatively high optical yield (10–30 % ee) for styrene, MA, and MMA, whereas almost no significant chiral induction was observed with the use of 3. Specifically, the highest ee was obtained for 1 with the use of styrene (32 % ee) whereas the highest ee for 2 was observed with the use of MA (21 % ee) and MMA (13 % ee). All of the metal complexes induced radical polymerizations of these vinyl monomers in conjunction with a series of haloesters as an initiator. Some systems can control the molecular weights and the terminal groups by the ruthenium-catalyzed reversible activation of the carbon–halogen bond. However, no tacticity control was achieved with all of these DIOP-based ruthenium complexes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Electronic effects of the substituents on the phenyl ring of the phenyl(bisoxazoline) ligand skeleton of rhodium catalysts was examined in the asymmetric reductive aldol reactions of acrylates and aldehydes. The electron-withdrawing NO2 group of Rh(4-NO2-Phebox-R)(OAc)2 showed an increase in the enantioselectivity of the products in the reductive reaction of methyl acrylate but not in the reactions of tert-butyl- and trimethylsilyl acrylates. Theoretical calculations of the corresponding model rhodium-Phebox complexes indicate that the remote electron-withdrawing substituent slightly shortens the Rh–Cphebox bond. Also, the Rh–C bonds of Rh(4-NO2-Phebox-iPr)(OAc)2 and the corresponding Rh(4-H-Phebox-iPr)(OAc)2 were compared on the basis of X-ray analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The bis(oxazolinyl)-3,5-dimethylphenylrhodium and -iridium complexes were synthesized in high yields by an efficient C&bond;H bond activation method with 4,6-dimethyl-1,3-bis(oxazolinyl)benzene derivatives. The catalytic activity of the complexes was examined for the asymmetric conjugate reduction of (E)-ethyl 3-phenylbut-2-enoate and the asymmetric reductive aldol reaction of tert-butyl acrylate and benzaldehyde. It was found that the rhodium complex of 3,5-dmPhebox showed the higher catalytic activity, whereas the corresponding iridium complexes proved to be less active.

Novel heterotrimetallic polyhydrido complexes containing ruthenium and group 6 metals, (Cp‘Ru)2(Cp‘M)(μ-H)5 (4, M = Mo; 5, M = W) and (Cp‘Ru)(Cp‘W)2(H)7 (6), have been synthesized by the reaction of dimeric ruthenium methoxo complex (Cp‘RuOMe)2 (3) with dinuclear polyhydrido complexes Cp‘Ru(μ-H)3MH3Cp‘ (1, M = Mo; 2, M = W) and (Cp‘WH4)2, respectively. The 1H NMR spectra of 6 exhibit fluxionality stemming from the dynamic motion of the RuW2 core associated with exchange of the coordination sites among the hydrido ligands.

We studied the histopathology of spastic muscles in patients with spastic cerebral palsy using specimens obtained from the gastrocnemius muscles during orthopedic operations. Though there was no disease-specific abnormality, we found changes in fiber type distribution, i.e., type-1 fiber predominance and type-2B fiber deficiency. These changes were not found in the patient with brain infarction at age 1 year 5 months. Variation in fiber size, especially in type-1 fibers, was also detected in older patients and at the more severely affected sides. We speculated that the influence on the spinal motor unit from upper motor cortex might be applicable to the muscle histological findings and the time of the onset of the brain damage might be important.

Using Wechsler Intelligence Tests, we compared the intellectual status of children with cerebral palsy (CP) immediately before and 2 years after entering school. Verbal and performance IQs could be assessed for 23 children with spastic diplegia but only verbal IQs in six children with spastic quadriplegia. Performance IQs were much lower than verbal IQs in both the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) in children with spastic diplegia. After schooling, verbal IQ was significantly increased but there was no change in performance IQ, thus, the difference between these IQs became more pronounced. When comparing the school class types, the verbal IQs of children studying in ordinary classes became statistically higher than those of children in special classes. In contrast, since the increases in mean performance IQs were greater in children in special classes, the differences between these IQs became more pronounced in children studying in ordinary classes. We also found that although verbal IQs were lower for quadriplegic children than for diplegic children at preschool age, there was no difference after 2 years of schooling. These results underline the importance and benefits of appropriate education for children with CP.

The unique C−C bond formation reaction between diisopropylamine and CH2Cl2proceeding on a bis(oxazolinyl)phenyl rhodium complex (tBu-Phebox-dm)RhCl2(H2O) (1) was discovered. The intermediary chloromethyl complex, (tBu-Phebox-dm)Rh(CH2Cl)Cl(NEt3), which was obtained by reaction of 1with CH2Cl2in the presence of amine, underwent C−C bond formation with imine to give an azarhodacyclopentene complex, 2.

Self-folding resorcinarenes bearing optically active urea moieties showed unique circular dichroism (CD) phenomena on the macrocyclic skeleton, which were caused by their chiral urea termini through intramolecular hydrogen bonding interactions in chloroform. These characteristic CD bands were disappeared upon complexation with anions such as chloride and bromide.

Review: ca. 100 refs.

Review: 33 refs.

Treatment of indoles with nonhindered silanes in the presence of (I) allows facile selective access to 3‐silylated indoles.

The (S,S)‐BOPA/FeCl2complex (II) is activated in the presence of Zn and affords the (S)‐configurated alcohol.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.