Diinsertion of fluorenylidene into a sulfur-sulfur bond of diaryl disulfides

Upon irradiation (>340 nm) of a benzene solution of diazofluorene with di-p-tolyl- or di-p-anisyl disulfide, the corresponding 9,9′-bis(arylmercapto)bifluorenyl was afforded in moderate to good yield accompanied by formation of 9,9′-bis(arylmercapto)fluorene. The major reaction pathway is considered to be a disulfur ylide formation followed by two times of successive Stevens rearrangement or by concerted electron redistribution via [2,3]sigmatropic rearrangement.     

Determination of plasma protein binding of propafenone in rats, dogs and humans by highly sensitive gas chromatography-mass spectrometry

A highly sensitive method for the determination of propafenone in plasma has been established using gas chromatography-mass spectrometry with the deuterium-labelled compound as an internal standard. Plasma levels as low as 1 ng/ml were measured using 0.5-ml plasma samples. Plasma protein binding of the drug in rats, dogs and humans in vitro and in vivo was determined by the proposed method. About 90% of the drug was bound to the plasma protein in all species in vitro (20-500 ng/ml) and 69-88% in rats, 90-95% in dogs and 77-89% in humans after oral administration of the drug at doses of 50 mg/kg, 5 mg/kg and 200 mg per person, respectively.     

Evaluation of prognosis in patients with old myocardial infarction--using 201Tl myocardial scintigraphy and 99mTc cardiac scintigraphy

To evaluate the prognosis in 57 patients with old myocardial infarctions, 201Tl myocardial scintigraphy and 99mTc-HSA gated blood pool scan had been done as a 5-year follow up study. We subdivided into two groups; group I (over 60 years) and group II (under 60 years). Cardiac index (CI) and right ventricular ejection fraction (RVEF) did not change significantly, however left ventricular ejection fraction (LVEF) changed significantly (p less than 0.05). Correlationship between CAG score and delta LVEF by handgrip exercise test was y = -1.34 x +3.61 (n = 44, r = -0.400, p less than 0.01). Otherwise, Tl defect ratio between first and final examination did not show the significant change in two groups. In conclusion, nuclear examination (cardiac function and myocardial blood flow) is significant to evaluate the prognosis in patients with myocardial infarction.     

Determination of ammonium ion in a flow-injection system with a gas-diffusion membrane : Selection of Optimal Conditions for the pH Indicator

The spectrophotometric determination of ammonium ion in water by flow-injection analysis with a membrane-separator and a pH indicator for detection is studied in detail. The relations derived facilitate the selection of appropriate solution compositions or the prediction of sensitivity. It is shown that 1.5×10^?5 M bromocresol purple (pH 6.8) as acceptor solution gives the maximal sensitivity in the flow system with a laboratory-made separation unit. Application of ultrasonic radiation in the separation step and the use of different flow rates for the donor and acceptor streams may result in increased permeation of ammonia and a correspondingly high sensitivity. By modifying the acceptor solution so that the sensitivity is decreased, more concentrated samples such as urine can be analyzed by direct injection without prior dilution. In this procedure, the sample rate was 60 h^?1 for ammonium concentration of more than 10^?5 M and 30–40 h^?1 for concentrations in the range 3×10^?7?10^?5 M. The detection limit was about 3×10^?7 M.     

Enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones using a novel N,N,P–Cu(II) complex

Enantioselective copper-catalyzed 1,4-additions of dialkylzincs to enones were carried out in the presence of 1 mol % of Cu(OTf)₂ and 2.5 mol % of an N,N,P-ligand possessing a tert-butyl group at the adjacent position of the nitrogen of pyridine to afford the corresponding 1,4-adducts in up to 98% ee.     

Synthesis of Bis(phosphanyl)alkane Monosulfides by the Addition of Diphosphane Monosulfides to Alkenes under Light

Bis-phosphanated compounds are regarded as the most ubiquitous privileged ligand structures in transition-metal catalysis. The development of highly atom economical reactions is of great importance for their syntheses because less atom economical methods often require complicated purification procedures under inert atmospheres to remove excess starting materials and byproducts. Herein, the photoinduced addition reactions of diphosphane monosulfides bearing P^V(S)−P^III single bonds to alkenes is disclosed. These reactions require only equimolar amounts of the diphosphane monosulfide relative to the alkene and facilitate highly selective introduction of two different types of phosphorus-containing groups, such as thiophosphoryl and phosphanyl groups, into a variety of alkenes without any catalyst, base, or additive.