The oxidative coupling of indole with some phenolic compounds,naphthols and catechols

The oxidative coupling of indole with three naphthols, 2-naphthol, 2,3-dihydroxynaphthalene and 2,7-dihydroxynaphthalene gave 1,1-bis(3′-indolyl)-2(1H)naphthalenone, 1,1-bis(3′-indolyl)-3-hydroxy-2(1H)naphthalenone and 1,1-bis(3′-indolyl)-7-hydroxy-2(1H)naphthalenone, respectively. The coupling of indole with protocatechuic aldehyde gave bis-(3-indolyl)-(3′,4′-di-hydroxyphenyl)methane and that of indole with homocatechol gave 3-(2′-methyl-3′,4′-di-hydroxyphenyl)indole.     

New approach to a novel axially chiral ligand showing spontaneous enrichment of axial chirality

We have synthesized novel axially chiral ligand with two chiral centers, (R)-(R)(2)- and (S)-(S)(2)-2,2'-bis(2,2,2-trifluoro-1-hydroxyethyl)biphenyl (1), which showed a high asymmetric induction when used as ligand. Here, another new approach to 1 by kinetic and thermodynamic resolution is presented which gave these ligands in a much shorter steps, in a higher yield, and in a higher enantiomeric excess.     

Reactions of β-sulfenyl α,β-unsaturated ketones with guanidine,Amidines, and diamines

β-Sulfenyl α, β-unsaturated ketones 1a-c reacted with guanidine or amidines to give pyrimidine derivatives 3 in 14-76% yields. Treatment of ketones 1 with diamines such as ethylenediamine and o -phenylenediamine afforded the seven-membered heterocycles, 2,3-dihydro-1,4-diazepine 5 and 2,3-benzo-1,4-diazepines 8a-c .     

Line tension and wetting behavior of an air/hexadecane/aqueous surfactant system

The line tension of an air/hexadecane/aqueous solution of an dodecyltrimethylammonium bromide (DTAB) system was measured as a function of the molality of DTAB at 298.15 K by means of a newly constructed apparatus. It was estimated to be on the order of 10(-10)-10(-12) N, which is comparable to the theoretical estimation. Furthermore, its sign was reversed from positive to negative in the vicinity of the wetting transition concentration. The reversal of the sign was examined on the basis of our experimental findings on the wetting transition and the theory of Indekeu.     

Reaction of 6-phenyl-2-(p-toluenesulfonyl)-3(2H)pyridazinone with grignard reagents

6-Phenyl-2-(p-toluenesulfonyl)-3(2H)pyridazinone (I) reacted with Grignard reagents to give 5-substituted 4,5-dihydro-3(2H)pyridazinones II and two types of dihydropyridazines, III and IV. The ratio of II, III, and IV was sensitively dependent on the reaction conditions. Further, by quenching the reaction mixture with alcohol, the ring-opened product VII was mainly isolated.     

The reaction of 3-(1-imidazolyl)-2-alken-1-ones with nucleophiles

Generally 3-hetero-substituted 2-alken-1-ones were prepared from 1,3-alkanediones, 3-chloro-2-alken-1-ones, or conjugated ynones. The preparation of 3-hetero-substituted 2-alken-1-ones was subjected to some limitations by these methods. By the reaction of 3-(1-imidazolyl)-2-alken-1-ones (I) and 3-(3-oxo-1-alkenyl)-1-methylimidazolium iodides (II) with nucleophiles, 3-hetero-substituted 2-alken-1-ones could be obtained regioselectively in good yield under mild conditions. These results suggested that compounds I and II were concluded to be useful intermediates for the organic synthesis.     

The photochemistry of α,β-acetylenic ketones. II. Formation of furan derivatives

The photochemical reactions of α,β-acetylenic ketones have been examined. Irradiation of 1-p-substituted phenyl-2-propyn-1-ones 2–4 in primary alcohols gave 2,5-disubstituted furans 2a–4c. The formation of furans can be explained in terms of cyclization, followed by dehydration of the 1:1-adduct of acetylenic ketone and alcohol, which was formed initially by hydrogen atom abstraction from alcohol by the excited acetylenic ketone. Irradiation of 1-p-tolyl-2-propyn-1-one ( 2 ) in ethanol-d₁ yielded 2-methyl-5-p-tolylfuran ( 2b ) containing no deuterium. This result was consistent with a mechanism that involves hydrogen atom abstraction from alcohol by the carbon of triple bond rather than abstraction by carbonyl oxygen.     

Synthesis of new synthons for organofluorine compounds from halothane containing sulfur functional groups

To develop new synthons for the syntheses of organofluorine compounds, the treatment of Halothane, 2-bromo-2-chloro-1,1,1-trifluoroethane, (1) with 4-methylbenzenethiol (2) in the presence of sodium hydride gave 1-chloro-2,2,2-trifluoroethyl 4-methylphenyl sulfide (3), which was oxidized with m-chloroperbenzoic acid (m-CPBA) to the corresponding sulfoxide (4) and sulfone (5). Reaction of 3 and 5 with allyltributyltin in the presence of 2,2'-azobis(isobutyronitrile) (AIBN) gave 1-(trifluoromethyl)-3-butenyl compounds (9, 11). Sulfoxide 4 was decomposed in this condition. The treatment of 3 with allyltrimethylsilane in the presence of Lewis acids gave 1-(trifluoromethyl)-3-butenyl compounds (9) in good yield. This result suggests that 4-methylphenylthio substituent stabilizes the alpha-carbocation effectively, though the trifluoromethyl group destabilizes it strongly. Aromatic compounds similarly reacted with 3 in the presence of titanium(IV) chloride to give 2-aryl-1,1,1-trifluoro-2-(4-methylphenylthio)ethanes. Thus, sulfur compounds derived from Halothane were found to be useful new synthons for organofluorine compounds.     

New conditions for validity of the centroid molecular dynamics and ring polymer molecular dynamics

Validity of the centroid molecular dynamics (CMD) and ring polymer molecular dynamics (RPMD) in quantum liquids is studied on an assumption that momenta of liquid particles relax fast. The projection operator method allows one to derive the generalized Langevin equation including a memory effect for the full-quantum canonical (Kubo-transformed) correlation function. Similar equations for the CMD and RPMD correlation functions can be derived too. The comparison of these equations leads to conditions under which the RPMD and CMD correlation functions agree approximately with the full-quantum canonical correlation function. The condition for the RPMD is that the memory effects of the full-quantum and RPMD equations vanish quickly with the same time constants. The CMD correlation function requires additional conditions concerning static correlation.     

Detection and quantitative estimation of metalloporphyrins in vivo

Spectrofluorometry, radioisotope (RI) labelling and high performance liquid chromatography (HPLC) can be used to estimate photosensitizer concentrations. The biodistribution of porphyrins and metalloporphyrins containing the bifunctional chelating agent diethylenetriamine pentaacetic acid (DTPA) was examined in tumour-bearing mice by nitrogen-pulsed laser spectrofluorometry (PLS) and RI labelling. The biodistribution of metalloporphyrin amino acid derivatives containing alkoxyl groups was also examined by PLS and HPLC analysis using an acetone powder extraction method. Spectrofluorometry is useful for estimating the biodistribution of porphyrins in tumour, lung, kidney and serum, but not in liver. However, spectrofluorometry cannot be used to evaluate the concentration of certain metalloporphyrins such as manganese complexes. The concentrations of porphyrins in liver measured by PLS and two other methods showed remarkable differences. RI labelling and HPLC analysis are obviously tedious methods. Therefore it seems practical to screen for a number of compounds using the spectrofluorometric method (PLS). Subsequently, the porphyrins which give good results with PLS should be measured using RI labelling and HPLC.