TiCl4-promoted cyclization reactions of aminoacetals and ethenetricarboxylates leading to nitrogen-containing heterocycles.

Lewis acid-catalyzed cyclization of aminoacetals 2 and triethyl ethenetricarboxylate (1a) has been examined. The reaction of 3-aminopropionaldehyde diethyl acetal (2a) and 1a in the presence of 1 equiv of TiCl(4) at room temperature gave 4-ethoxypiperidine-2,3,3-tricarboxylate 3a in 92% yield with a 2,4-diastereomer ratio of 1:1. The reaction in the presence of 3 equiv of TiCl(4) gave 2,4-trans-piperidine derivative 3a in 86% yield predominantly.

A significant role of alkaline cations on the Reimer-Tiemann reaction.

The Reimer-Tiemann (R-T) reaction was investigated by DFT calculations. A model composed of CHCl(3), PhO(-)(Na(+))H(2)O and [NaOH(H(2)O)(2)](2) was employed for geometry optimizations. A K(+)-containing model was also investigated.

Effects on incidental memory of affective tone in associated past and future episodes: influence of emotional intelligence.

The present study examined the effects of emotion elicited by episodes (past events or expected future events) and the relationship between individual differences in emotional intelligence and memory. Participants' emotional intelligence was assessed on the Japanese version of Emotional Skills and Competence Questionnaire. They rated the pleasantness of episodes they associated with targets, and then performed unexpected free recall tests.

Psychological and neuroendocrinological effects of odor of saffron (Crocus sativus).

Aim: The purpose of this study was to clarify the effects of saffron odor on symptoms unique to women, such as premenstrual syndrome (PMS), dysmenorrhea (menstrual pain) and irregular menstruation.

Materials And Methods: Thirty-five women with a normal sense of smell were exposed to saffron odor for 20 min. Saliva samples were then collected to measure levels of cortisol (C), testosterone (T) and 17-β estradiol (E) by enzyme immunoassay, and the State-Trait Anxiety Inventory (STAI) was administered as a psychological test.

[The effects of dietary calcium and protein intake on changes in bone mineral density during early and late stages of pregnancy].

Objective: The study was performed to examine the effects of calcium (Ca) and protein intake on changes in bone mineral density during early and late stages of pregnancy, including the relationship to bone metabolism.

Subjects And Methods: In 40 pregnant women, bone mineral density (BMD) was measured three times: at 11-16 weeks of gestation, at 24-28 weeks and within one week postpartum using ultrasonic bone densitometry. Bone metabolic markers in urine and serum were measured at the same time points.

Correlation between the rate order and the number of molecules in the reaction of trimethyl phosphite with water in acetonitrile solvent.

Density functional theory calculations of the title reaction, P(OCH₃)₃ + (H₂O)(n) in CH₃CN, were conducted, where n is the number of water molecules. Two routes, the routes suggested by (A) Aksnes and (B) Arbuzov, were traced with various n values. Both routes consist of two transition states (TSs) and one intermediate.

The native structure of cytoplasmic dynein at work translocating vesicles in Paramecium.

In Paramecium multimicronucleatum, the discoidal vesicles, the acidosomes and the 100-nm carrier vesicles are involved in phagosome formation, phagosome acidification and endosomal processing, respectively. Numerous cross bridges link these vesicles to the kinetic side of the microtubules of a cytopharyngeal microtubular ribbon. Vesicles are translocated along these ribbons in a minus-end direction towards the cytopharynx.

Lewis acid promoted reactions of ethenetricarboxylates with allenes: synthesis of indenes and gamma-lactones via conjugate addition/cyclization reaction.

Indenes are important core structures in organic chemistry. Few simple arylallenes have been used to construct indene skeletons by Friedel-Crafts reaction. Lewis acid catalyzed reaction of ethenetricarboxylates 1 and arylallenes has been examined in this study.

Zn(OTf)2-catalyzed reactions of ethenetricarboxylates with 2-aminobenzaldehydes leading to tetrahydroquinoline derivatives.

Quinolines are an important class of compounds, and the development of new efficient synthetic strategies for the construction of quinolines is of considerable interest. Zinc triflate catalyzed cyclization of ethenetricarboxylate derivatives with 2-aminobenzaldehydes has been examined. The reaction of ethenetricarboxylate with 2-aminobenzaldehydes in the presence of zinc triflate (0.

Time-resolved electron spin resonance spectroscopy of radicals formed during free radical polymerizations of alkyl acrylates.

Time-resolved electron spin resonance (TR ESR) spectra allows direct observation of transient radicals (primary propagating radicals) obtained by the addition reaction of a diphenylphosphinoyl radical to acrylates. The addition rate constants (k(2) ) of the diphenylphosphinoyl radical to the acrylates (initiation rate constants) were determined by the monomer concentration dependence of the decay rate of the diphenylphosphinoyl radical. The value of k(2) was 1.

pi Complexes in benzidine rearrangement.

By the use of DFT calculations, the title rearrangement, Ph-NH-NH-Ph () --> H(2)N-C(6)H(4)-C(6)H(4)-NH(2) (2), was studied for the first time. Although it is a classical reaction (found in 1862), its mechanism is almost entirely unknown. There are three complexities associated with this mechanism.

Effects of the time dimension and presentation on incidental memory.

Undergraduates were presented targets on two occasions, and each time they were asked to choose one of two alternatives (past or future) associated with the targets in the orienting task, followed by an unexpected free recall. For the pleasant targets, the spaced presentation led to a better recall than the massed presentation for both past and future time. However, for unpleasant targets, the spacing effect was found in recall of targets associated with the past but the effect was not observed in recall of targets associated with the future.

Zinc-catalyzed reactions of ethenetricarboxylates with 2-(trimethylsilylethynyl)anilines leading to bridged quinoline derivatives.

Zinc Lewis acid-catalyzed cyclization of ethenetricarboxylate derivatives 1 with 2-ethynylanilines has been examined. Reaction of 1,1-diethyl 2-tert-butyl ethenetricarboxylate 1b with 2-(trimethylsilylethynyl)aniline substrates in the presence of Zn(OTf)(2) gave bridged quinoline derivatives in 43-85% yield. The reaction of 1b with 2'-aminoacetophenone also gave the bridged quinoline derivative in 41% yield.

Three competitive transition states in the benzoin condensation compared to the clear rate-determining step in the Cannizzaro reaction.

The Cannizzaro reaction ("RX C") and the benzoin reaction ("RX B") were investigated by density functional theory calculations. Reaction models (benzaldehyde)2 + X(-) + (H2O)n [for X(-) = OH(-) (RX C) n = 8, and for X(-) = CN(-) (RX B) n = 8 or n = 14] were adopted. Three transition states (TSs) were obtained for RX C, and the rate-determining step was confirmed to be the hydride shift.

Efficient synthesis of heterocyclic compounds using ethenetricarboxylic acid diesters.

Ethenetricarboxylic acid diester 1a is a useful compound bearing two reactive sites, a CO2H group and a Michael acceptor. Reactions of 1a and reagents with oxygen and nitrogen nucleophilic moieties have been examined. The reaction of 1a with 2-aminoalcohols in the presence of EDCI and HOBt in one pot gave N,O-containing heterocyclic compounds, regioselectively.

A new mechanism for the Favorskii rearrangement.

The title reaction was investigated by the use of ONIOM-RB3LYP calculations. A reaction system composed of alpha-chlorocyclohexanone, a methoxide ion and 8 MeOH solvent molecules was adopted. Two reaction channels, the semibenzilic acid mechanism (A) and cyclopropanone mechanism (B), were compared.

Music facilitate the neurogenesis, regeneration and repair of neurons.

Experience has shown that therapy using music for therapeutic purposes has certain effects on neuropsychiatric disorders (both functional and organic disorders). However, the mechanisms of action underlying music therapy remain unknown, and scientific clarification has not advanced. While that study disproved the Mozart effect, the effects of music on the human body and mind were not disproved.

Efficient synthesis of methylenetetrahydrofurans and methylenepyrrolidines by formal [3+2] cycloadditions of propargyl substrates.

Recent developments concerning the synthesis of methylenetetrahydrofurans and methylenepyrrolidines by one-pot formal [3+2] cycloadditions involving propargylic (and allylic) alcohols and amines with electrophilic alkenes are described. The synthetic methods provide powerful tools to prepare highly functionalized oxygen- and nitrogen-containing five-membered ring systems. The reactions can be effectively promoted by base, base/transition metals, and Lewis acids, depending on the substrates.

Development of a Japanese version of the emotional skills and competence questionnaire.

The present study described development of a Japanese version of the Emotional Skills and Competence Questionnaire and examined the relations of scores with those on Big Five scales of personality and self-esteem scales. The participants were 615 undergraduates. Factor analysis led to the shortened version of 24 items in three subscales.

The effects of odor on cortisol and testosterone in healthy adults.

Objectives: This study aimed to verify the influence of odor on the endocrine system (Cortisol, Testosterone).

Material And Methods: Three odors (Musk, Rose and Floral) and air were given to 16 healthy volunteers (8 males, 8 females), and cortisol (C) and testosterone (T) levels were measured before and after stimulation.

Results: Each odor decreased levels of C, indicating that odor can attenuate stress.

Lewis acid-catalyzed conjugate addition-cyclization reactions of ethenetricarboxylates with substituted propargyl alcohols: stereoselectivity in the efficient one-pot synthesis of methylenetetrahydrofurans.

Oxygen-containing heterocyclic systems are important structures in organic chemistry because of their presence in many biologically active compounds. In this work, a Lewis acid-catalyzed cyclization of ethenetricarboxylate derivatives 1 with substituted propargyl alcohols to give methylenetetrahydrofurans was investigated. Reaction of 1 and gamma-silicon-substituted propargyl alcohols 4 with ZnBr2 at 80-110 degrees C led to (Z)-silicon-substituted products stereoselectively.

Reaction paths of the water-assisted solvolysis of N,N-dimethylformamide.

Density functional theory calculations were conducted on the title reactions with explicit inclusion of a variety of water molecules, H-CO-NMe2+MeOH+(H2O)n-->H-CO-OMe+HNMe2+(H2O)n. Geometries of transition states, reactant-like complexes and product-like ones were determined by the use of RB3LYP/6-31G(d) SCRF=dipole. Concerted paths were examined with n=0-3.

Characteristic features in the collision of chemical waves depending on the aspect ratio of a rectangular field.

The photosensitive Belousov-Zhabotinsky (BZ) reaction was investigated on a double rectangular field composed of two rectangular routes, which was drawn using computer software and then projected using a liquid-crystal projector on a filter paper soaked with BZ solution. When two chemical waves were generated on the rectangular routes as the initial condition, the nature of the collision of the waves could be theoretically classified into four categories depending on the initial phase difference between the two waves and the aspect ratio of the rectangular routes. The experimental results were consistent with the features of the theoretical prediction.

The role of hydrogen bonds in Baeyer-Villiger reactions.

Various Baeyer-Villiger (B-V) oxidation reactions were examined by density functional theory calculations. Proton movements in transition states (TSs) of the two key steps, the nucleophilic addition of a peroxyacid molecule to a ketone (TS1) and the migration-cleavage of O-O (TS3), were discussed. A new TS of a hydrogen-bond rearrangement in the Criegee intermediate (TS2) was found.

Reaction of o-benzyne with tropothione involving biradical processes.

A benzyne-tropothione reaction was studied experimentally and computationally. Three isomeric products were detected by a careful experiment using two benzyne sources. The three equimolar products were identified.