The pKa values and the 1H NMR spectra of tetraarylporphyrins in the presence of cyclodextrins suggest that the microscopic environment of the positively polarized cavity of cyclodextrin promotes the inclusion of the anionic guest and prohibits the penetration of the cationic guest into the cyclodextrin cavity.

A novel mixed-valence Cu(I)-Cu(II) coordination polymer with an infinite two-dimensional structure, [Cu3(I)Cu(II)Br3(3,5-Dmpip-dtc)2]n (3,5-Dmpip-dtc(-) = 3,5-dimethylpiperidine dithiocarbamate), was prepared, and its structure was characterized by X-ray diffraction. It shows semiconducting behavior with a relatively small activation energy and high carrier mobility, which were investigated using impedance spectroscopy and flash photolysis time-resolved microwave conductivity measurements, respectively.

IntroductionSeveral reports have described the usefulness of a high-flow nasal cannula (HFNC). However, the physiological mechanisms of this system are unclear. In the current study, various methods were used to investigate the physiological mechanisms of an HFNC in healthy volunteers.MethodsThe physiological mechanisms of the constant-flow and constant-pressure models of HFNC were studied in 10 healthy volunteers by the oesophageal balloon method, the electrical impedance method and the forced oscillation technique (FOT).ResultsThe tidal volume (TV) increased markedly during HFNC (off, 30 L/min, 50 L/min: 685.6±236.5 mL, 929.8±434.7 mL, 968.8±451.1 mL). The end-inspiratory oesophageal pressure (EIOP) was not significantly different, but there was a tendency for it to decrease. HFNC 30 L/min and 50 L/min, the increment in TV and the difference in EIOP showed strong negative correlations (p=0.0025, 0.003). The end-expiratory oesophageal pressure (EEOP) increased. The respiratory system reactance at 5 Hz (X5) by FOT decreased significantly. There was a flow rate-dependent EEOP increase, and the positive end-expiratory pressure (PEEP) effect of HFNC was confirmed. There was a correlation between the difference in X5 and the difference in EEOP during HFNC 30 L/min and 50 L/min, with correlation coefficients of 0.534 and 0.404 (p=0.112, 0.281). The amount of change in EEOP and the fluctuation in X5 were positively correlated.ConclusionsThe PEEP effect of HFNC was confirmed by the electrical impedance method and FOT. The increment in TV and the difference in EIOP of HFNC showed strong negative correlations.

A site‐divergent stereoselective Michael reaction system is developed based on the identification of two distinct catalysts. Cinchonidine‐derived thiourea catalyzes the 1,4‐addition of prochiral azlactone enolates to enynyl N‐acyl pyrazoles in a highly diastereo‐ and enantioselective manner to give stereochemically defined alkynes, while P‐spiro chiral triaminoiminophosphorane catalytically controls the stereoselective 1,6‐addition and the consecutive γ‐protonation of the vinylogous enolate intermediate to afford Z,E‐configured conjugated dienes. This 1,6‐adduct serves as a valuable precursor for the synthesis of a 2‐amino‐2‐deoxy sugar.

As ite-divergent stereoselective Michael reaction system is developed based on the identification of two distinct catalysts.C inchonidine-derived thiourea catalyzest he 1,4addition of prochiral azlactone enolates to enynyl N-acyl pyrazoles in ahighly diastereo-and enantioselective manner to give stereochemically defined alkynes,w hile P-spiro chiral triaminoiminophosphorane catalytically controls the stereoselective 1,6-addition and the consecutive g-protonation of the vinylogous enolate intermediate to affordZ ,E-configured conjugated dienes.T his 1,6-adduct serves as av aluable precursor for the synthesis of a2 -amino-2-deoxy sugar.

New mixed-valence Cu(I)-Cu(II) coordination polymers with one-dimensional, infinite-chain structures, [Cu(I)(2)Cu(II)X(2)(Hm-dtc)(2)(CH(3)CN)(2)](n) [Hm-dtc(-) = hexamethylene dithiocarbamate; X = Br(-) (1), I(-) (2)], have been prepared and structurally characterized by X-ray diffraction. These complexes consist of a mononuclear copper(II) unit Cu(II)(Hm-dtc)(2) and dinuclear copper(I) units Cu(I)(2)(CH(3)CN)(2)X(2). Magnetic studies have revealed that these complexes have a relatively strong antiferromagnetic interaction [J = -26.9 cm(-1) (1) and J = -22.2 cm(-1) (2)] between the unpaired electrons of the Cu(II) ions through the dinuclear copper(I) halide unit of Cu(I)(2)X(2) in the chain. The electrical properties of 1 and 2 are investigated using an impedance spectroscopy technique, and it is revealed that these complexes exhibit intriguing semiconducting properties with small activation energies [E(a) = 0.562 eV (1) and E(a) = 0.479 eV (2)].

A metal-free stereoselective reductive coupling reaction between isatins and aldehydes is reported. The reaction relies on commercial diethyl phosphite (∼€70 kg−1) as the stoichiometric reductant. Base-catalyzed Pudovik addition and phosphonate/phosphate rearrangement achieved polarity inversion on the isatin, and the derived carbanions were trapped by aldehydes with subsequent dialkoxyphosphinyl migration. Chiral iminophosphoranes were used as basic catalysts to achieve high diastereo- and enantioselectivities with excellent yields.

A novel class of chiral N-sulfonyl oxaziridines is introduced for use as structurally modifiable chiral oxidants. These oxaziridines are readily prepared from N-sulfonyl α-imino esters in a highly enantioenriched form by oxidation with hydrogen peroxide using l-isoleucine-derived triaminoiminophosphorane as a catalyst. The distinct advantage of their structural modularity is demonstrated through the identification of an optimal oxaziridine that exhibits high reactivity and enantiospecificity in the asymmetric oxidation of a silyl enol ether and N-sulfonyl allylic and homoallylic amines.