Metal-Free Directed Site-Selective Csp3 -H Borylation of Saturated Cyclic Amines.

The borylation of Csp3 -H bonds is a challenging transformation that is typically restricted to transition metal catalysis. Herein, we report the site-selective metal-free Csp3 -H borylation of saturated cyclic amines. It is possible to selectively borylate piperidine derivatives at the α or ß positions according to the reaction conditions. The mechanism was supported by NMR spectroscopy, calorimetry experiments and density functional theory (DFT) computations. It suggests that the piperidine is dehydrogenated by complexation with BBr3 to produce an enamine intermediate, which is in turn borylated at either the α or ß position according to the reaction conditions.

Heterolytic Oxidative Addition of sp2 and sp3 C-H Bonds by Metal-Ligand Cooperation with an Electron-Deficient Cyclopentadienone Iridium Complex.

Oxidative addition reactions of C-H bonds that generate metal-carbon-bond-containing reactive intermediates have played essential roles in the field of organometallic chemistry. Herein, we prepared a cyclopentadienone iridium(I) complex 1 designed for oxidative C-H bond additions. The complex cleaves the various sp2 and sp3 C-H bonds including those in hexane and methane as inferred from their H/D exchange reactions. The hydroxycyclopentadienyl(nitromethyl)iridium(III) complex 2 was formed when the complex was treated with nitromethane, which highlights this elementary metal-ligand cooperative C-H bond oxidative addition reaction. Mechanistic investigations suggested the C-H bond cleavage is mediated by polar functional groups in substrates or another iridium complex. We found that ligands that are more electron-deficient lead to more favorable reactions, in sharp contrast to classical metal-centered oxidative additions. This trend is in good agreement with the proposed mechanism, in which C-H bond cleavage is accompanied by two-electron transfer from the metal center to the cyclopentadienone ligand. The complex was further applied to catalytic transfer-dehydrogenation of tetrahydrofuran (THF).

Cleavage of Si-H, B-H, and C-H Bonds by Metal-Ligand Cooperation.

Metal-ligand cooperation, in which metal and ligand participate in bond cleavage and formation, is gathering great attention in recent years. In contrast to the classical bond cleavage by active metal centers with spectator ligands, metal-ligand cooperation has enabled unprecedented reactivities. Especially, metal-ligand cooperative H-H bond cleavage has been extensively studied and applied to various catalysts. On the other hand, there are substantial efforts to expand the scope of the bond to be cleaved other than the H-H bond. This review summarizes the recent progress in the metal-ligand cooperative cleavages of Si-H, B-H, and C-H bonds and their catalytic applications.

Umpolung of B-H Bonds by Metal-Ligand Cooperation with Cyclopentadienone Iridium Complexes.

In contrast to conventional metal-ligand cooperative cleavage of a B-H bond, which provides a B cation on the ligand and an H anion on the metal, we report herein the umpolung of B-H bonds by novel cyclopentadienone iridium complexes. The B-H bonds of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin) and 1,8-naphthalenediaminatoborane (HBdan) were cleaved to give a B anion on the metal and an H cation on the phenolic oxygen atom of the ligand. Mechanistic investigation by DFT calculations revealed that the alkoxycarbonyl-substituted cyclopentadienone ligand facilitated deprotonation from Ir-H after oxidative addition of the B-H bond to give the umpolung product. The generated boryliridium complex was found to undergo borylation of an allyl halide in the presence of base, thus showing the nucleophilic nature of the boron atom.

Metal-Ligand Cooperative C-H Bond Formation by Cyclopentadienone Platinum Complexes.

C-H bond cleavage and formation is one of the most essential elementary reactions in organic chemistry. Herein, a heterolytic sp3 C-H bond reductive elimination from hydroxyCp dimethylplatinum(IV) B is reported. Protonation of cyclopentadienone dimethylplatinum(II) A afforded B via the protonation of the ligand. Successive C-H bond formation from the C anion of the methyl group and the H cation of the hydroxyCp group was observed in the presence of carboxylic acids or hydrogen chloride. The reaction was accompanied by the concurrent reduction of Pt(IV) to Pt(II). Experimental and theoretical investigations suggested that the mechanism for the C-H bond formation was acid-mediated metal-ligand cooperative outer-sphere reductive elimination.

Molecular Packing Structure of Mesogenic Octa-Hexyl Substituted Phthalocyanine Thin Film by X-ray Diffraction Analysis.

The molecular packing structure in a thin film of the liquid crystalline phthalocyanine, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2), which is a promising small-molecular material for solution-processable organic thin-film solar cells, has been investigated by X-ray diffraction (XRD) measurement. The crystal structure of C6PcH2 in the spin-coated film was determined to be a centered rectangular structure (a = 36.4 Å, b = 20.3 Å). The tilt angle of the phthalocyanine core normal vector was 34-39° from the column axis, and the shortest intermolecular distance was 3.9-4.0 A. The crystal structure determined by XRD analysis was ascertained to be consistent with that calculated by Fourier analvsis.

The feasibility of measuring joint angular velocity with a gyro-sensor.

OBJECTIVES: To determine the reliability of an assessment of joint angular velocity using a gyro-sensor and to examine the relationship between ankle angular velocity and physical functions. DESIGN: Cross-sectional. SETTING: Kinesiology laboratory. PARTICIPANTS: Twenty healthy young adults (mean age, 22.5 y) and 113 community-dwelling older adults (mean age, 75.1 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Maximal ankle joint velocity was measured using a gyro-sensor during heel-rising and jumping with knee extended. The intraclass correlation coefficient (ICC) was used to determine the intertester and intratester reliability. The Pearson correlation coefficient was used to examine the relationships between maximal ankle joint velocity and isometric muscle strength and isokinetic muscle power in young adults and also to examine the relationships between maximal ankle joint velocity and functional performance measurements such as walking time in older adults. RESULTS: High reliability was found for intertester (ICC=.96) and intratester reliability (ICC=.96). The data from the gyro-sensor highly correlated with muscle strength (r range, .62-.68; P<.01) and muscle power (r range, .45-.79; P range, .01-.05). In older subjects, mobility functions significantly correlated with the angular velocity of ankle plantarflexion. CONCLUSIONS: Measurement of ankle angular velocity using a gyro-sensor is both reliable and feasible, with the results representing a significant correlation to muscle power and performance measurements.

[Clinical features and prognosis of terminally ill patients in a geriatric long-term care hospital with particular regard to the implications of artificial nutrition].

AIM: To clarify the clinical features of terminally ill patients in our hospital and elucidate the implications of administering artificial nutrition. METHODS: Between April 2004 and March 2005, we assessed 155 patients who died in Nishimaruyama Hospital--a geriatric long-term care facility in Sapporo. We analyzed their clinical backgrounds on admission, the clinical course up to the terminal stage of the illness, and the outcome of patients who received artificial nutrition. RESULTS: In 95 patients, the main cause of the terminal illness was infection. The symptoms of these patients, such as cerebral infarction and cognitive dysfunction, deteriorated progressively, and eventually, eating became difficult. At this point, alternative methods for providing nutrition were discussed. For 60 patients (41 died of acute disease and 19, of advanced cancers), artificial nutrition was not considered. Artificial nutrition was administered to 63 patients; tube feeding was carried out in 30 patients. Because of repeated aspiration pneumonia, 14 of these 30 patients eventually underwent intravenous hyperalimentation (IVH). Thirty-three patients directly underwent IVH. Thirty-two patients did not undergo any feeding course. The mean survival times of the tube feeding and non-artificial nutrition groups were 827 and 60 days, respectively. The difference in the survival times was statistically significant. CONCLUSION: The outcome of patients who were placed on tube feeding was good. This may be because we selected those patients considered most suitable for tube feeding or IVH. The criteria that were used to select an appropriate method for providing nutrition varied, although the patients in our hospital requested palliative care.

Primary CD30/Ki-1 positive anaplastic large cell lymphoma of the central nervous system occurring in a patient with a seventeen-year history of essential thrombocythemia.

We present a rare case of central nervous system lymphoma that occurred in a patient who had essential thrombocythemia for 17 years. MRI examinations disclosed multiple ring-enhanced lesions that had shown bilateral spreading in the different period. Pathological examinations confirmed CD30/Ki-1-positive ALK negative anaplastic large cell lymphoma. The possible pathogenic mechanisms of this disease are discussed.

A possible involvement of the carboxymethylation process in carpal tunnel syndrome in hemodialysis patients.

A median motor nerve latency (DML) is generally prolonged in the carpal tunnel syndrome (CTS) of hemodialysis patients. Meanwhile, the advanced glycation process of proteins has been reported to be involved in the pathogenesis of the dialysis related amyloidosis. To investigate the role of carboxymethylation in dialysis related CTS, we measured a circulating carboxymethyllysine-hemoglobin (CML-Hb) level and nerve conduction velocity in 44 hemodialysis patients. The circulating CML-Hb level was 6.56 +/- 3.18 nmol CML/mg Hb, median motor nerve conduction velocity (NCV) was 49.8 +/- 4.64 m/s, median DML was 4.44 +/- 1.06 ms, and difference between median DML and ulnar DML (Delta DML) was 1.68 +/- 1.09 ms. Median and ulnar nerve NCV showed no correlation with circulating CML-Hb level. Both median DML and Delta DML were significantly correlated with CML-Hb (r = 0.429, P = 0.003, r = 0.472, P = 0.001). This study provided additional clinical evidence of an involvement of an advanced glycation process in the pathogenesis in CTS in hemodialysis patients.

Cervical myelopathy due to a "tight dural canal in flexion" with a posterior epidural cavity.

A 41-year-old man noticed weakness and atrophy in his right hand and forearm resembling the non-progressive juvenile muscular atrophy of unilateral upper extremity (Hirayama's disease). MRI showed an abnormal cavity in the posterior epidural space which appeared on neck flexion communicating with the subarachnoid space in addition to the flattening of the lower cervical spinal cord on neck flexion. When evaluating atypical cases of Hirayama's disease, the pathomechanism demonstrated in the present case should be taken into consideration.

Rapidly progressive Guillain-Barré syndrome following Escherichia coli infection.

Guillain-Barré Syndrome (GBS) is a prototype of post-infectious autoimmune disease. A 76-year-old woman was treated for a renal abscess and developed muscle weakness in all four extremities, 18 days after the onset of infection. She was diagnosed with GBS on the basis of acute flaccid paralysis, hyporeflexia, nerve conduction studies (reduced amplitude of compound muscle action potentials), and high titers of IgG antibodies to GM1 and GalNAc-GD1a. GBS rarely occurs after sepsis and this case represents the first report of rapidly progressive GBS following Escherichia coli urosepsis.

An in vitro evaluation of the glycation potential of a natural disaccharide, trehalose.

BACKGROUND: Glucose, an osmotic agent generally used in continuous ambulatory peritoneal dialysis (CAPD) dialysate, has a critical characteristic of forming advanced glycation endproducts (AGEs). We undertook this study to investigate whether a possible osmotic agent, trehalose, formed fewer AGEs than glucose. METHODS: Hemoglobin (Hb), a counter-protein of AGE, was incubated in four kinds of medium; glucose-phosphate buffered saline (PBS), autoclaved glucose-PBS, trehalose-PBS, and autoclaved trehalose-PBS, for 3, 7, 14, and 30 days, respectively. Polymerization of the Hb molecule was detected by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and carboxymethylated Hb was detected by Western blotting, using specific mono-clonal antibody for carboxymethylated N-terminal valine-Hb (CMV-Hb). RESULTS: PBS containing glucose showed bands of polymerized Hb molecule, a phenomenon which was markedly exaggerated by autoclaving. Likely, PBS containing glucose showed the formation of CMV-Hb in the long incubation of 30 days, and PBS containing autoclaved glucose showed accelerated formation of CMV-Hb in an incubation as short as 3 days. By contrast, PBS containing trehalose showed much less increase in a band of 30 k Dalton and in CMV-Hb formation even in autoclaved medium. CONCLUSIONS: Our present in vitro study clearly showed the superior characteristic of trehalose to produce fewer AGEs. Based upon the results of this study, we propose that the application of trehalose should be considered for CAPD solution.