Palladium(0)-catalyzed stereoselective cyclization of allenenes: divergent synthesis of pyrrolidines and 3-azabicyclo[3.1.0]hexanes from single allenenes

Two novel palladium(0)-catalyzed cyclizations of allenenes are described. Treatment of allenenes such as N-(1-alkyl-2,3-butadienyl)-N-allylsulfonamide with an aryl halide and K(2)CO(3) in the presence of a catalytic amount of Pd(PPh(3))(4) in dioxane affords 2,3-cis-pyrrolidines in a stereoselective manner. In sharp contrast, cyclization of the same allenenes using catalytic Pd(2)(dba)(3) x CHCl(3) in the presence of allyl methyl carbonate in CH(3)CN leads to stereoselective formation of a 3-azabicyclo[3.1.0]hexane framework in moderate yields.     

Synthesis, conformation and PKC isozyme surrogate binding of indolinelactam-Vs, new conformationally restricted analogues of (−)-indolactam-V

New conformationally restricted analogues of tumor promoter (−)-indolactam-V (1), indolinelactam-Vs (8, 11) and their hexyl derivatives at position 1 or 7 (9, 10, 12, 13), were synthesized from 1. (3R)-Indolinelactam-V (8) adopted a conformation similar to the twist form of 1 with a cis amide, while the conformation of (3S)-indolinelactam-V (11) was close to that of the sofa form of 1 with a trans amide. 7-Hexyl derivatives of 8 and 11 (10, 13) showed binding affinities for C1 domains of protein kinase C (PKC) isozymes compared to 1, but exhibited little selectivity among these PKC isozymes. However, introduction of the hexyl group at position 1 of 8 and 11 significantly enhanced their binding selectivity for novel PKC isozymes. The best selectivity for novel PKC isozymes was observed in (3S)-1-hexylindolinelactam-V (12) with a sofa-like conformation. These results suggest that a sofa-restricted analogue of 1 with a hydrophobic chain at an appropriate position would be a promising lead for designing agents with a high selectivity for novel PKC isozymes.     

Potential energy surfaces and nonadiabatic transitions in the asymptotic regions of ICN photodissociation to study the interference effects in the F1 and F2 spin-rotation levels of the CN products

One of the most spectacular yet unsolved problems for the ICN -band photodissociation is the non-statistical spin-rotation F₁ = N + 1/2 and F₂ = N − 1/2 populations for each rotation level N of the CN fragment. The F₁/F₂ population difference function f(N) exhibits strong N and λ dependences with an oscillatory behavior. Such details were found to critically depend on the number of open-channel product states, namely, whether both I (²P_3/2) and I (²P_1/2) are energetically available or not as the dissociation partner. First, in the asymptotic region, the exchange and dipole-quadrupole inter-fragment interactions were studied in detail. Then, as the diabatic basis, we took the appropriate symmetry adapted products of the electronic and rotational wavefunctions for the F₁ and F₂ levels at the dissociation limits. We found that the adiabatic Hamiltonian exhibits Rosen–Zener–Demkov type nonadiabatic transitions reflecting the switch between the exchange interaction and the small but finite spin-rotation interaction within CN at the asymptotic region. This non-crossing type nonadiabatic transition occurs with the probability 1/2, that is, at the diabatic limit through a sudden switch of the quantization axis for CN spin S from the dissociation axis to the CN rotation axis N . We have derived semiclassical formulae for f(N) and the orientation parameters with a two-state model including the 3A′ and 4A′ electronic states, and with a four-state model including the 3A′ through 6A′ electronic states. These two kinds of interfering models explain general features of the F₁ and F₂ level populations observed by Zare's group and Hall's group, respectively. © 2018 Wiley Periodicals, Inc.     

A highly cis-selective synthesis of 2-ethynylaziridines by intramolecular amination of chiral bromoallenes: improvement of stereoselectivity based on the computational investigation

The base-mediated intramolecular amination of bromoallenes having an axial chirality is described. The treatment of (4S,aR)-4-alkyl-4-[N-(arylsulfonyl)amino]-1-bromobuta-1,2-dienes with NaH in DMF affords 2,3-cis-2-ethynylaziridines in good to excellent selectivity (2,3-cis:trans = 92:8-99:1). The reaction of (4S,aS)-bromoallenes with NaH/DMF also gives 2,3-cis-2-ethynylaziridines selectively (79:21-91:9). These experimental results have been rationalized by B3LYP density functional calculations together with the 6-31+G(d) basis set and the Onsager solvation model. The transition structures for cis-aziridine formation of both (4S,aR)- and (4S,aS)-bromoallenes in DMF are favored over the corresponding trans transition structures by 4.35 and 1.41 kcal/mol, respectively. Furthermore, the calculations predicted that a less polar solvent gives higher cis selectivity for (4S,aS)-bromoallenes. In fact, improvement of the cis selectivity to 99:1 has been realized by using a less polar solvent such as THF. The cyclization of bromoallenes bearing a beta- or gamma-amino group also affords four- and five-membered azacycles in a highly cis-selective manner.     

Dynamic coordination polymers with 4,4'-oxybis(benzoate): reversible transformations of nano- and nonporous coordination frameworks responding to present solvents

Reversible construction of a nanoporous framework from a nonporous framework has been found in the zinc(II) coordination polymer with 4,4'-oxybis(benzoate) (oba). [Zn(2)(oba)(2)(dmf)(2)].2DMF (1), which has 1 nm scale channels, transforms to the nonporous coordination polymer [Zn(oba)(H(2)O)] (2) with the loss of the open framework. Compound 2 on treatment with DMF reversibly yields nanoporous compound 1.     

Outcomes of Physiotherapy on Activities of Daily Living and Discharge to the Community in Psychiatric Long-term Care Ward Patients

Objective: The purpose of this study was to investigate the outcomes of physiotherapy on patients in psychiatric long-term care wards in Japan and to identify the characteristics of patients who have been discharged to the community. Methods: The subjects comprised 50 patients who were admitted to the psychiatric long-term care wards at four different hospitals in Japan and prescribed physiotherapy. General physiotherapy for the patients’ diseases was provided. The main outcome was whether a patient was discharged to the community (discharged group) or remained hospitalized (hospitalized group) at the end of physiotherapy. Basic subject characteristics, including age, sex, F-code, classification of the diagnosis that led to physiotherapy, length of hospital stay, and length of physiotherapy, were collected from medical records. The Functional Independence Measure (FIM) tool was administered at the initial and final evaluations. Results: At the end of physiotherapy, there were 14 subjects in the discharged group and 36 subjects in the hospitalized group. There were significant differences in the classification of diagnosis, length of stay (LOS), and classification of LOS between the two groups. Two-way analysis of variance showed interactions between the FIM subitems of self-care, transfer, and locomotion. Conclusion: The discharged group had higher FIM scores at the start of physiotherapy and a greater FIM gain.     

Discrete palladium clusters that consist of two mutually bisecting perpendicular planes

The construction of novel molecules with unprecedented alignments of the constituent elements has revolutionized the field of functional materials. The arrangement of two or more planar subunits in a mutually perpendicular fashion is a frequently encountered approach to produce novel functional materials. Previous examples of such materials can be categorized into two well-investigated families: spiro-conjugated and dumbbell-shaped structures, wherein the two planes are aligned orthogonally via a single atom or an axis, respectively. This article describes a third family: reaction of [Pd(CN^tBu)₂]₃ with Sn₃Me₈ or Ge₆Me₁₂ afforded a Pd₇Sn₄ cluster and a Pd₈Ge₆ cluster that consist of two mutually bisecting perpendicular planes. In the Pd₇Sn₄ cluster, the two equivalent Pd₅Sn₂ planes share three palladium atoms that include a dihedral angle of 85.6°.

The construction of Pd₇Sn₄ and Pd₈Ge₆ clusters that consist of two mutually bisecting perpendicular planes was accomplished by the reaction of [Pd(CN^tBu)₂]₃ with Me₃Sn–SnMe₂–SnMe₃ or Ge₆Me₁₂.     

Azolium/Hydroquinone Organo-Radical Co-Catalysis: Aerobic C−C-Bond Cleavage in Ketones

Organo-radical catalysts have recently attracted great interest, and the development of this field can be expected to broaden the applications of organocatalysis. Herein, the first example of a radical-generating system is reported that does not require any photoirradiation, radical initiators, or preactivated substrates. The oxidative C−C-bond cleavage of 2-substituted cyclohexanones was achieved using an azolium salt and a hydroquinone as co-catalysts. A catalytic mechanism was proposed based on the results of diffusion-ordered spectroscopy and cyclic voltammetry measurements, as well as computational studies.     

Self-oscillation of polymer chains induced by the Belousov-Zhabotinsky reaction under acid-free conditions

A novel self-oscillating polymer was prepared by utilizing the Belousov-Zhabotinsky (BZ) reaction. In this study, a sulfonic acid group was newly introduced as a pH-control site into the copolymer of N-isopropylacrylamide, and the ruthenium complex was introduced as a catalyst site. By introducing the pH-control site, we succeed in causing the soluble-insoluble self-oscillation of the polymer solution under acid-free conditions in which only two BZ substrates, malonic acid and sodium bromate, were present as added agents. The self-oscillating behavior was remarkably influenced by the temperature and polymer concentration, which reflects the intermolecular aggregative capacity of the polymer chains in the reduced state to change the lower critical solution temperature. This achievement of self-oscillation of polymer chains under acid-free conditions may lead to their practical use as novel biomimetic materials under biological conditions.     

Preparation of Sr2CeO4:Eu3+,Dy3+ white luminescence phosphor particles and thin films by using an emulsion liquid membrane system

Sr(2)CeO(4) and Sr(2)CeO(4):Eu(3+),Dy(3+) phosphor particles and thin films were prepared by using an emulsion liquid membrane (ELM, water-in-oil-in-water (W/O/W) emulsion) system, containing VA-10 (2-methyl-2-ethylheptanoic acid) as extractant (cation carrier). A two-step extraction enabled efficient extraction for Sr(3+) and rare earth ions, and the resulting precursor metal oxalate particles produced in the internal water phase of the ELM system were about 60 nm in diameter. Calcination of the oxalate particles in air gave submicrometer-sized Sr(2)CeO(4) and Sr(2)CeO(4):Eu(3+),Dy(3+) particles, which showed blue and white luminescence, respectively, by UV excitation. Blue and white luminescence phosphor thin films were also prepared by soaking alumina substrates into the W/O emulsion containing precursor oxalate particles, followed by calcination in air.