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The 9-substituted anthracene derivative forms a spatially restricted dimer in the cavity of γ-cyclodextrin and exhibits circularly polarised luminescence with gCPL = +1.3 × 10−3 in the solid state.

The relationship between the lactim-lactam tautomerization and the free-radical scavenging reaction in vitamin B9 [folic acid (FA)] was investigated by density functional theory calculations. 6-Methylpterin was also adopted for the detailed analyses of various reaction paths. For pterin, the transition state of the tautomerization with two water molecules (n = 2) was calculated to be of the lowest activation energy. The proton-transfer circuit of n = 2 is retained (not broken) even with the addition of outer water molecules, n = 2 + 2, 2 + 4, 2 + 8, and 2 + 14. At the oxidation of the system composed of 6-methylpterin + (H2O)2 + HO•, the radical character of HO• is directly transmitted to the pterin ring along with the C-O → H → O → H → O → H → OH proton transfer. The patterns of the electron transfer (pterin ring → OX•) and the concomitant proton transfer via the water dimer were commonly obtained for the oxidant (OX•) = HO•, Cl3C-O2•, N3•, or SO4-•. The hydrogen atom transfer mechanism was ruled out. Two conformations of the puckered form with the -C(═O)-OH···N intramolecular hydrogen bonds of FA were found to have the stability similar to that of the linear conformer. Both the tautomerization and the oxidation were calculated to occur competitively in the three conformers.

Intramolecular cycloaddition reactions of α-bromostyrene-functionalized amides of monomethyl fumarate were investigated. The reaction of the amides with Et

Density functional theory (DFT) calculations of reactions between 2′-deoxyguanosine (dR-Gua) and hydroxyl radical (HO•) with water molecules (H2O)n, n = 0, 1, and 2, were carried out. The HO• addit...

Background Metabolic disorders are important pathophysiologies that can cause multiple organ dysfunction and worsen prognosis in Fontan patients. This study aimed to comprehensively evaluate the metabolomic profile of adult Fontan patients and characterize its pathophysiology in relation to 2 control groups. Methods and Results We performed metabolomic analysis of 31 plasma samples using capillary electrophoresis time-of-flight mass spectrometry. This observational cross-sectional study compared plasma metabolites of 14 heterogeneous adult Fontan patients with those of control groups, including 9 patients with congenital heart disease after biventricular repair and 8 normal healthy controls. Fontan patients exhibited significant differences in intermediate metabolite concentrations related to glycolysis, the tricarboxylic acid (TCA) cycle, and the urea cycle. The plasma concentrations of lactic acid, 2-oxoglutarate, isocitric acid, malic acid, cis-aconitic acid, arginine, citrulline, and the ratio of ornithine/citrulline showed significantly differences among the groups. Multiple logistic regression analysis with a stepwise selection-elimination method identified 2-oxoglutaric acid (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.05–3.76) and cis-aconitic acid (OR 2.69, 95% CI 1.04–6.99) as independently associated with Fontan patients. After adjustment for the covariates of age and gender, 2-oxoglutaric acid (OR 1.97, 95% CI 0.98–3.93) and cis-aconitic acid (OR 3.88, 95% CI 0.99–15.2) showed remarkable relationships with Fontan patients. Conclusions The present findings suggest that abnormalities in the TCA cycle and amino acid metabolism are distinguishing features in the pathophysiology of Fontan patients. Future metabolomic studies will assist in developing biomarkers for the early prediction of “silent” Fontan pathophysiologies.

Intramolecular [2 + 2] and [4 + 2] cycloaddition reactions of cinnamylamides of ethenetricarboxylate in sequential processes have been studied. Reaction of 1,1-diethyl 2-hydrogen ethenetricarboxylate and trans-cinnamylamines in the presence of EDCI/HOBt/Et3N led to pyrrolidine products in one pot, via intramolecular [2 + 2], [4 + 2], and some other cyclizations. The types of the products depend on the substituents on the benzene ring and the reaction conditions. Reaction of cinnamylamines without substituents on the benzene ring and with halogens and OMe on the para position at room temperature gave cyclobutane-fused pyrrolidines as major products via [2 + 2] cycloaddition. The reaction at 80 °C in 1,2-dichloroethane gave δ-lactone fused pyrrolidines as major products, probably via ring-opening of the cyclobutanes. Interestingly, reaction of 1,1-diethyl 2-hydrogen ethenetricarboxylate and cinnamylamines bearing electron-withdrawing groups such as NO2, CN, CO2Me, CO2Et, and CF3 on ortho and para positions ...

The stereospecificity of the cyclization reaction of (E)- and (Z)-2-alkenyl esters and amides of ethenetricarboxylate has been examined. The reaction of (E)/(Z)-2-butenyl esters with AlCl3 or FeCl3 gave trans-substituted chlorinated γ-lactone diastereomers stereospecifically. (E)/(Z)-2-butenyl and pentenyl amides undergo an intramolecular ene reaction at room temperature gradually. At 80 °C, the (Z)-alkenyl amides were transformed to cis-substituted ene adducts and the (E)-amides were transformed to cis- and trans-substituted ene adduct mixtures. The reaction of (E)/(Z)-2-alkenyl amides with ZnI2 gave trans-substituted γ-lactam diastereomers stereospecifically along with the ene adducts.

Catalytic cyclization of amides of ethenetricarboxylate bearing ether and acetal groups has been examined. The reaction of the amides bearing cyclic ether and acetal groups in the presence of Lewis acid such as Sc(OTf)3 gave spirocyclic piperidine derivatives as major products. The cyclized products may be formed via intramolecular hydride transfer. The reaction mechanism was examined by the DFT calculations. The scope and limitations of the hydride transfer/cyclization reactions of amides of ethenetricarboxylates was investigated, and morpholine formation by intramolecular oxy-Michael addition was also found.

BACKGROUND Kawasaki disease (KD) is classified as a systemic vasculitis syndrome and QT interval dispersion (QTD) has been associated with cardiac involvement and disease activity in patients with cardiovasculitis. We examined whether baseline QTD could predict a response to intravenous immunoglobulin (IVIG) in KD.Methods and Results:QTD was recorded in 86 patients with KD before IVIG, who were separated into IVIG responders (R group; n=62) and nonresponders (N group; n=24). The association between baseline QTD and response to IVIG was investigated, and the predictive response value was compared with conventional risk scores from Gunma and Kurume universities. Baseline-corrected QTDs with Bazett's (QTbcD) and Fridericia's (QTfcD) formulae were significantly increased in the N group (R group vs. N group: 31.6 [28.3, 44.0] ms vs. 66.6 [50.5, 76.3] ms and 27.4 [25.2, 39.1] ms vs. 55.2 [42.4, 66.3] ms, respectively, both P

Lewis acid-promoted intramolecular reactions of alkenyl ethenetricarboxylates and the corresponding amides have been examined. Reaction of allyl ethenetricarboxylates and the amides with Lewis acids (1-2 equiv) such as TiCl4, TiBr4, AlCl3, and AlBr3 gave 3,4-trans-halogenomethyl 2-oxotetrahydrofuran and pyrrolidine derivatives stereoselectively in high yields. The stereochemistries were determined by NOE experiments. Reaction of alkyl-substituted allylic ethenetricarboxylates with Lewis acids gave chloro 2-oxotetrahydrofurans and pyrans. For some alkyl-substituted substrates, cationic intermediates may be formed under the reaction conditions, and rearranged products have been obtained.

Two Prins reactions were investigated by the use of DFT calculations. A model composed of R–CH=CH2 + H3O+(H2O)13 + (H2C=O)2, R = Me and Ph, was adopted to trace reaction paths. For both alkenes, the concerted path forming 1,3-diols was obtained as the rate determining step (TS1). TS stands for a transition state. From the 1,3-diol, a bimolecular elimination (TS2) leads to the allylic alcohol as the first channel. In the second channel, the 1,3-diol was converted via TS3 into an unprecedented hemiacetal intermediate, HO–CH2–O–CH(R)–CH2–CH2–OH. This intermediate undergoes ring closure (TS4), affording the 1,3-dioxane product. The intermediate is of almost the same stability as the product, and two species were suggested to be in a state of equilibrium. While the geometry of TS1 appears to be forwarded to that of a carbocation intermediate, the cation disappeared through the enlargement of the water cluster. Dynamical calculations of a classical trajectory using the atom-centered density matrix propagation molecular dynamics model on the four TSs were carried out, and results of IRC calculations were confirmed by them.

Wild-type Acetobacter aceti NBRC 14818 possesses genes encoding isocitrate lyase (aceA) and malate synthase (glcB), which constitute the glyoxylate pathway. In contrast, several acetic acid bacteria that are utilized for vinegar production lack these genes. Here, an aceA-glcB knockout mutant of NBRC 14818 was constructed and used for investigating the role of the glyoxylate pathway in acetate productivity. In medium containing ethanol as a carbon source, the mutant grew normally during ethanol oxidation to acetate, but exhibited slower growth than that of the wild-type strain as the accumulated acetate was oxidized. The mutant grew similarly to that of the wild-type strain in medium containing glucose as a carbon source, indicating that the glyoxylate pathway was not necessary for glucose utilization. However, in medium containing both ethanol and glucose, the mutant exhibited significantly poorer growth and lower glucose consumption compared to the wild-type strain. Notably, the mutant oxidized ethanol nearly stoichiometrically to acetate, which was retained in the medium for a longer period of time than the acetate produced by wild-type strain. The features of the aceA-glcB knockout mutant revealed here indicate that the lack of the glyoxylate pathway is advantageous for industrial vinegar production by A. aceti.

BACKGROUND The characteristics of aortic elasticity are unclear in children with connective tissue disorders (CTDs) such as Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), especially in those with a non-dilated aortic root (AoR). This study evaluated the aortic elasticity properties of pediatric MFS and LDS patients with either dilated or non-dilated AoR.Methods and Results:The 31 children with MFS or LDS were classified into dilated (Z score of AoR diameter ≥2.5; n=17) or non-dilated (Z score of AoR diameter

BACKGROUND The purpose of this study was to clarify cardiovascular structure and function in small for gestational age (SGA) infants across a range of intrauterine growth restriction (IUGR) severity. METHODS AND RESULTS This prospective study included 38 SGA infants and 30 appropriate for gestational age (AGA) infants. SGA infants were subclassified into severe and mild SGA according to the degree of IUGR. Cardiovascular structure and function were evaluated using echocardiography at 1 week of age. Compared with the AGA infants, both the severe and mild SGA infants showed increased left ventricular diastolic dimensions (severe SGA 10.2±2.4, mild SGA 8.2±1.3, and AGA 7.3±0.7 mm/kg, P

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. The reaction of aminoacetaldehyde diethyl/dimethyl acetals 2c,d and 1a with 3 equiv of TiCl(4) gave 2,4-trans-4-pyrrolidine-2,3,3-tricarboxylates 5a,b predominantly.

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. Route B was found to be more likely than route A. In the former, the activation free energy (ΔG(‡)) of n = 3 is slightly smaller than that of n = 2. The n = 3 TS geometry is composed of a nucleophile H₂O, a proton donor H₂O, and an auxiliary one. Indeed, the geometry appears to be plausible for ready proton relays along hydrogen bonds, but it is inconsistent with the observed third-order rate constant. Catalytic water molecules were added to the n = 2 and 3 bond-interchange circuits. Then route B with n = 2 + 2 was found to be best. By n = 2 + 10 and n = 3 + 12 models, the n = 2 based route B was confirmed to be likely.

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 (0.2 equiv) at 80 degrees C in ClCH(2)CH(2)Cl gave bridged tetrahydroquinoline derivatives in 15-95% yield. On the other hand, the reaction at room temperature in CH(2)Cl(2) gave hydroxy tetrahydroquinoline derivatives in 38-90% yield. Heating the hydroxy tetrahydroquinolines with zinc triflate (0.2 equiv) at 80 degrees C in ClCH(2)CH(2)Cl led to the bridged tetrahydroquinoline derivatives in 75-96% yield. Thermal reaction of the bridged tetrahydroquinolines (180 degrees C) gave indole derivatives regioselectively.

The distribution of lysosomes during porcine oocyte maturation and fertilization in vitro was revealed by using acridine orange staining. The lysosomal distribution was classified into three types: generally even distribution throughout the ooplasm (Type I), less distribution in the peripheral ooplasm (Type II), and less distribution in the peripheral and inner ooplasm (Type III). All oocytes examined at 0 and 8 h after maturation culture showed the Type I lysosome distribution and 97% were at the germinal vesicle (GV) stage. When cultured for 22 h, the relative abundance of Type I oocytes decreased to 58%, while Type II and Type III oocytes appeared at relative abundances of 35 and 8%, respectively. After 32 and 44 h of culture, 35 and 80% of the oocytes, respectively, were Type III. When cultured with olomoucine, IBMX or dbcAMP for 22 h, 100, 79 and 94% of the oocytes, respectively, showed the Type I distribution of lysosomes, and their nuclei were almost all at the GV stage (100, 93 and 100%). The results of the present study suggest that there may be a close relationship between nuclear maturation and the distribution of lysosomes in the cytoplasm, and that the distribution of lysosomes may be one of the criteria of cytoplasmic maturation of porcine oocytes.

Density functional and ONIOM calculations of alcohol and phenol additions to two (tetramethyl and tetramesityl) disilenes were carried out. The dimer of MeOH adds to Me 2 Si SiMe 2 more readily than the monomer. The trimer does not afford the adduct, but a zwitter-ionic intermediate. In the (CF 3 OH) 2 addition to Me 2 Si SiMe 2 , H⋯Si bond formation is more advanced than O⋯Si bond formation in the transition state (TS). Addition of seven phenol derivatives to Me 2 Si SiMe 2 was examined, and the dimer reactions were found to be superior to the monomer reaction regardless of the substituents on the benzene rings. (MeOH) 2 reacts also with Mes 2 Si SiMes 2 favorably, and an isomer of the reactant-like complex (precursor) may afford an adduct of different stereochemistry via internal rotations. Generally, the dimer of the alcohol or phenol is the reactant toward the disilenes. Exceptionally, a monomer of p -(dimethylamino)phenol reacts with Mes 2 Si SiMes 2 owing to steric congestion by the four mesityl groups.

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 of 1 and gamma-ester-substituted propargyl alcohol 7 in the presence of various Lewis acids gave ester-substituted methylenetetrahydrofurans stereoselectively. Interesting Lewis acid dependency on stereoselectivity for the reaction of 7 was found. Reaction of alpha-substituted propargyl alcohols also gave cyclized products.

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. The hydrogen-bond directionality requires a trimer of the peroxyacid molecules at the nucleophilic addition of a peroxyacid molecule to a ketone TS (TS1). At the migration-cleavage of O-O TS (TS3), also three peroxyacid molecules are needed. Elementary processes of the B-V reaction were determined by the use of the (acetone and (H-CO-OOH)n, n=3) system. The geometries of the nucleophilic addition of a peroxyacid molecule to a ketone TS (TS1) and the migration-cleavage of O-O TS (TS3) in the trimer (n=3) participating are nearly insensitive to the substituent on the peroxyacid. The directionality is satisfied in those geometries. The migration-cleavage of O-O TS (TS3) was found to be rate-determining in reactions, [Me2C=O+(H-CO-OOH)3], [Me2C=O+(F3C-CO-OOH)3], and [Me2C=O+(MCPBA)3]. In contrast, the nucleophilic addition of a peroxyacid molecule to a ketone (TS1) is rate-determining in the reaction, [Ph(Me)C=O+(H-CO-OOH)3].

Modification of hydrogen-terminated Si(1 1 1) surfaces by hydrosilylation of activated alkenes and further chemical transformation of the modified surfaces is reported. A Si(1 1 1)–H surface was reacted with activated alkenes such as acrylate esters, acrylonitrile, and maleic anhydride under mild conditions to give modified surfaces with terminal functional groups. A modified surface with a terminal ester group was reduced by LiAlH 4 to give a hydroxy-terminated surface, and the hydroxy-terminated surface was transformed to a bromo-terminated surface. XPS analysis revealed that the brominated surface ( Si(1 1 1)–CH 2 CH 2 CH 2 Br) had 32% coverage with the 3-bromopropyl group. Ester and amide formation reactions were carried out on hydroxy- and carboxy-terminated Si surfaces by reaction with tert -butoxycarbonyl glycine, glycine tert -butyl ester, 2,2,2-trifluoroethanol and 4-trifluoromethylbenzyl alcohol in the presence of carbodiimide. XPS characterization indicated that the esters and amide were successfully formed with coverage ranging from 16% to 58%. Coverage ratios of octadecyl ester modified surfaces were also estimated by combination of surface reduction and gas chromatography analysis to be 25–35%.

A new zinc- and indium-promoted conjugate addition-cyclization reaction to afford nitrogen- and oxygen-containing five-membered heterocycles has been developed. Reaction of ethenetricarboxylates with propargylamines (1 equiv) in the presence of ZnBr2 or InBr3 afforded methylenepyrrolidines in high yields. The stoichiometric use of ZnBr2 or InBr3 at room temperature and the catalytic use of InBr3-Et3N at 80 degrees C were effective. Reaction of ethenetricarboxylates with propargyl alcohol in the presence of ZnBr2 or InBr3 afforded methylenetetrahydrofurans.

Reaction paths for the title rearrangement along with its methyl analogue were investigated by density functional theory calculations. The reaction model is R-CO-CO-R + OH(-)(H2O)4 --> R2C(OH)-COO- + (H2O)4 (R = Me and Ph), where the water tetramer is employed both for solvation to OH- and for the proton relay along hydrogen bonds. The reaction is composed of OH- addition, C-C rotation, carbanion [1,2] migration, and proton relay toward the product anions. The rate-determining step was calculated to be the carbanion migration. Apparently, carbanion [1,2] migration is unlikely relative to the carbonium ion one. However, LUMOs of the 1,2-diketones have large and nodeless lobes at the reaction center, the C1-C2 bond. The specific LUMO character is reflected both in the [2+1]-like one-center nucleophilic addition and in the carbanion [1,2] shift. The proton relay involved in the isomerization from the oxo intermediate to the carboxylate was calculated to take place via the water tetramer.

[reaction: see text] The Friedel-Crafts reaction is an important reaction for the formation of new C-C bonds. Recently, catalytic enantioselective Friedel-Crafts reaction of alkylidene malonates has been reported. However, the substituents in alkylidene malonates are limited. To explore new substituents such as carboxyl and carbonyl groups, catalytic enantioselective Friedel-Crafts reactions of reactive ethenetricarboxylates and acyl-substituted methylenemalonates 1 were investigated. The reaction of 1 with indoles in the presence of catalytic amounts of chiral bisoxazoline copper(II) complex (10%) in THF at room temperature gave alkylated products in high yields and up to 95% ee. The enantioselectivity can be explained by the secondary orbital interaction on approach of indole to the less hindered side of the 1-Cu(II)-ligand complex.

A novel cyclization of 1,1-diethyl 2-tert-butyl ethenetricarboxylate (1a) in the presence of a Lewis acid afforded a 5,5-dimethyl-gamma-lactone derivative 2a. The reaction process has been shown to arise from formation by trapping of isobutylene generated in situ. Lewis acid-promoted intermolecular reactions of 1,1-diethyl 2-hydrogen ethenetricarboxylate (5) and various alkenes to afford highly functionalized gamma-lactones were also developed. [reaction: see text]

In Japan, transdermal fentanyl (Durotep Patch) was launched in March 2002, and it was regarded as making opioid rotation possible. When changing from morphine to transdermal fentanyl, the efficacy ratio of 1:150 is used in Japan as well as in many other countries. However, the ratio of 1:100 is used in Germany. As a result, a dose increase in transdermal fentanyl is often required to control pain. We studied transdermal fentanyl use in the Aichi Cancer Center (ACC) to investigate the actual conversion ratio and appropriate switching by following up 144 patients (81 men, 63 women) who had received transdermal fentanyl in the ACC from March 19, 2002, to April 30, 2003. Transdermal fentanyl improved pain control in patients who had difficulty in tolerating oral medication or in continuing morphine because of side effects. Regression analysis indicated that the efficacy ratio of oral morphine to transdermal fentanyl was 1:78. As the fentanyl dosage was excessive even in some patients who followed the recommended morphine/fentanyl conversion of 150:1, it is dangerous to use the conversion ratio of 78:1 at first. Morphine side effects were reduced in some patients who changed to transdermal fentanyl, but there was no reduction in those who needed high-dose morphine for rescue analgesia. Therefore it is safe and effective to use low-dose transdermal fentanyl in the beginning and to control pain promptly using rescue morphine based on the present recommended dosage. For opioid rotation, quick-acting opioids other than morphine are expected to be launched in Japan.

Pericardial effusion is a potentially fatal complication following hematopoietic stem cell transplantation (HSCT). Therefore, the identification of risk factors could improve the outcome. Prolonged QT dispersion (QTD) and corrected QTD (QTcD) are associated with serious arrhythmias and sudden death in many forms of heart disease. However, no study has evaluated the efficacy of QTD and QTcD to predict pericardial effusion post-HSCT. We studied 89 pediatric HSCT patients to identify preoperative risk factors for pericardial effusion with particular focus on QTD and QTcD. Pericardial effusion occurred in 15 patients (cumulative onset rate: 17.4%) within one year post-HSCT, of which 8 (9.2%) were symptomatic. Patients with pericardial effusion following allogeneic HSCT showed significantly lower overall survival; however, pericardial effusion was not the direct cause of death in any patient. Univariate and multivariate analyses revealed that transplantation-associated thrombotic microangiopathy (TA-TMA) was an independent risk factor for post-HSCT pericardial effusion. In addition, pretransplant QTcD was significantly prolonged in the pericardial effusion group. These results suggest that pediatric patients with abnormally prolonged QTcD before the preparative regimen for HSCT should be regularly followed-up by echocardiography to detect pericardial effusion, particularly when accompanied by complications including TA-TMA.

Reaction of 1-(phenylseleno)-2-(trimethylsilyl)ethene 1 and methyl or ethyl 2-p-toluene- or benzenesulfonylacrylates 3 in the presence of SnCl4 at −78 °C gave sulfone-substituted cyclopropanes 4 as single stereoisomers. The structure of one of these crystalline cyclopropane products was elucidated by X-ray crystallographic analysis. The relative stereochemistry of the cyclopropane ring carbon (C2) and selenosilylmethyl group was determined as R,R and S,S, which is consistent with previous mechanical considerations and the NOE determination. 2-Sulfinyl acrylate 2 did not undergo this cycloaddition. The difference in reactivity of the sulfoxide 2 and sulfones 3 toward 1 was explained by comparison of LUMO levels of 2−SnCl4 and 3−SnCl4 complexes and activation energies in the synclinal addition of 1 to the complexes.

Reaction of 1-seleno-2-silylethenes 1 with the chiral electrophiles 2, 3, and 4 derived from (−)-menthol, in the presence of zinc halides gave the cyclopropane products 5, 6, and 7, respectively, w...

The reactions of (E)-1-(phenylseleno)-2-(trimethylsilyl)ethene (1a) and (E)-1-(phenylseleno)-2-(triethylsilyl)ethene (1b) with dimethyl 1,1-dicyanoethene-2,2-dicarboxylate (2) in the presence of SnCl4 in CH2Cl2 at −78 °C for 1 h exclusively afforded [2 + 2] cycloadducts 3a and 3b in 71% and 78% yields, respectively. The exclusive [2 + 2] selectivity in the reaction of 1 with 2 in the presence of SnCl4 is explained by destabilization of the proposed selenium-bridged intermediate that would lead to the [2 + 1] adduct by the presence of the two electron-withdrawing cyano groups. The reaction of 1a with 2 at 0 °C to room temperature in the presence of ZnBr2 gave a regioisomeric [2 + 2] cycloadduct 7a in low yield along with a corresponding desilylated cyclobutane 8 as the major product in moderate to good yield. The origin of the Lewis acid dependence of the regioselectivity was deduced from a theoretical comparison of stability of Lewis acid complexes.

Tick-borne encephalitis virus (TBEV) is a zoonotic agent causing severe encephalitis in humans. A recent epizootiological survey indicated that endemic foci of TBEV have been maintained in the southern part of Hokkaido until recently. In this study, we sought to isolate TBEV from wild rodents in the area. One virus, designated Oshima 08-As, was isolated from an Apodemus speciosus captured in Hokuto in 2008. Oshima 08-As was classified as the Far Eastern subtype of TBEV and formed a cluster with the other strains isolated in Hokkaido from 1995 to 1996. Thirty-six nucleotide differences resulted in 12 amino acid changes between Oshima 08-As and Oshima 5-10 isolated in 1995. Oshima 08-As caused high mortality and morbidity in a mouse model compared with Oshima 5-10. Although similar transient viral multiplication in the spleen was observed in the mice infected with Oshima 08-As and Oshima 5-10, greater viral multiplication with an inflammatory response was noted in the brains of mice infected with Oshima 08-As than those infected with Oshima 5-10. These data indicate that a few naturally occurring mutations affect the pathogenicity of the Oshima strains endemic in the southern part of Hokkaido.

A representative azulene formation from an active troponoid precursor (2-methoxytropone) and an active methylene compound (malononitrile) has been analyzed both experimentally and theoretically. (2)H-Tracer experiments using 2-methoxy[3,5,7-(2)H(3)]tropone (2-d(3)) and malononitrile anion give 2-amino-1,3-dicyano[4,6,8-(2)H(3)]azulene (1-d(3)) in quantitative yield. New and stable (2)H-incorporated reaction intermediates have been isolated, and main intermediates have been detected by careful low-temperature NMR measurements. The detection has been guided by mechanistic considerations and B3LYP/6-31(+)G(d) calculations. The facile and quantitative one-pot formation of azulene 1 has been found to consist of a number of consecutive elementary processes: (a) The troponoid substrate, 2-methoxytropone (2), is subject to a nucleophilic substitution by the attack of malononitrile anion (HC(CN)(2)(-)) to form a Meisenheimer-type complex 3, which is rapidly converted to 2-troponylmalononitrile anion (5). (b) The anion 5 is converted to an isolable intermediate, 2-imino-2H-cyclohepta[b]furan-3-carbonitrile (6), by the first ring closure in the reaction. (c) A nucleophilic addition of the second HC(CN)(2)(-) toward the imine 6 at the C-8a position produces the second Meisenheimer-type adduct 7. (d) The second ring closure leads to 1-carbamoyl-1,3-dicyano-2-imino-2,3-dihydroazulene (11). A base attacks the imine 11, which results in generation of a conjugate base 12 of the final product, azulene 1.

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. The reaction of arylallenes and ethenetricarboxylate triesters with SnCl(4) gave indene derivatives efficiently, via a conjugate addition/Friedel-Crafts cyclization reaction. On the other hand, the reactions of 1,1-diethyl 2-hydrogen ethenetricarboxylate and arylallenes or alkylallenes with SnCl(4) at -78 degrees C or room temperature and subsequent treatment with Et(3)N gave gamma-lactones. The reactions of triethyl ethenetricarboxylate and 1,1-dialkylallenes with SnCl(4) at room temperature also gave gamma-lactones.

Reaction of (Z)-2,3-bis(2-lithiophenyl)-2-butene (10) with selenium gave 12,13-dimethyldibenzo [d,h]-1,2,3-triselenonine (3) rather than either 11,12-dimethyldibenzo [c,g]-1,2-diselenocine (2) or 13,14-dimethyldibenzo [e,i]-1,2,3,4-tetraselenecine (4). Thermolysis and photolysis of 3 gave 5a,10a-dihydro-5a,10a-dimethyldibenzo-[b,f] seleno [3,2-b] selenophene (12) via extrusion of a selenium atom and a novel intramolecular addition of arylselenyls to a double bond. Ab initio molecular orbital calculations and X-ray structural analyses are made to elucidate the reaction mechanism

Lewis acid and substituent dependency on the regioselectivity of hydrosilylation of propiolate esters 1a-c with tris(trimethylsilyl)silane (2a) was found. The reaction of methyl and ethyl propiolate esters and 2a without Lewis acid and in the presence of EtAlCl2 and Et2AlCl gave beta-silicon-substituted Z-alkenes 3 selectively. On the other hand, reaction in the presence of AlCl3 in dichloromethane gave alpha-silicon-substituted alkenes 4. In the case of trifluoroethyl propiolate ester 1c, reaction with aluminum chloride-based Lewis acids gave alpha-silicon-substituted alkenes 4 exclusively. Two competitive mechanisms, free-radical and ionic, are proposed as the source of the complementary regioselectivity displayed in these reactions. A transition state of the radical-forming step was obtained computationally. The reaction of various reactive acetylene substrates and 2a without Lewis acid and without solvent at room temperature gave beta-silicon-substituted Z-alkenes 3 selectively.

The mechanism of stereoselective addition of Grignard reagents to carbonyl compounds has been investigated using B3LYP density functional theory calculations. The study of the reaction of methylmagnesium chloride and formaldehyde in dimethyl ether revealed a new reaction path involving carbonyl compound coordination to magnesium atoms in a dimeric Grignard reagent. The structure of the transition state for the addition step shows that an interaction between a vicinal-magnesium bonding alkyl group and C=O causes the C-C bond formation. The simplified mechanism shown by this model is in accord with the aggregation nature of Grignard reagents and their high reactivities toward carbonyl compounds. Concerted and four-centered formation of strong O-Mg and C-C bonds was suggested as a polar mechanism. When the alkyl group is bulky, C-C bond formation is blocked and the Mg-O bond formation takes precedence. A diradical is formed with the odd spins localized on the alkyl group and carbonyl moiety. Diradical formation and its recombination were suggested to be a single electron transfer (SET) process. The criteria for the concerted polar and stepwise SET processes were discussed in terms of precursor geometries and relative energies.

Reactions of enynes with three or two ester groups (1-4) in the presence of halogen-ligand Lewis acids gave cyclized products with halide incorporation (5-8) with high generality. The cyclization process was also analyzed in a theoretical study. Facile isomerization and dehydrohalogenation of five-membered products 5 and 8 by Al(2)O(3) or Et(3)N were also observed; this process introduces conjugated moieties into the products.