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The acylation and transesterification of alcohols with vinyl acetate and carboxylic esters were investigated in the presence of a catalytic amount (1–10 mol %) of dilithium tetra- tert -butylzincate (TBZL) as a catalyst. The acylation proceeded quantitatively at 0 °C within 1 h. The transesterification occurred for a wide range of combinations of esters and alcohols at 0 to −40 °C. To the best of our knowledge, this is the first successful transesterification at such low temperatures. The time–conversion plots for the transesterification show that the reaction reached equilibrium within 5 min at 0 °C. The reaction proceeded quantitatively by addition of molecular sieves 4A. In addition, the transesterification proceeded even in the presence of H 2 O and amines.

Asymmetric allylic alkylation of β-ketoesters with allylic alcohols catalyzed by [Ni(cod)2]/(S)-H8-BINAP was found to be a superior synthetic protocol for constructing quaternary chiral centers at the α-position of β-ketoesters. The reaction proceeded in high yield and with high enantioselectivity using various β-ketoesters and allylic alcohols, without any additional activators. The versatility of this methodology for accessing useful and enantioenriched products was demonstrated.

Ruthenium(II)-catalyzed hydrogen transfer from 2-propanol mediates reductive coupling of 1,1-disubstituted allenes with formaldimines with complete branch-regioselectivity, thus representing a new method for hydroaminomethylation beyond classical hydroformylation/reductive amination.

Asymmetric 1,3-dipolar cycloaddition reactions between N-methylindoles and several cyclic carbonyl ylides that were derived from diazodiketone or diazoketoester precursors in the presence of both achiral Rh and chiral lanthanoid metal catalysts are described. For the six-membered cyclic carbonyl ylides derived from 1-diazo-5-aryl-2,5-pentanedione precursors, the cycloaddition reactions were carried out using Rh2(OAc)4 (2 mol %) and the chiral Pybox-Ph2-Lu(OTf)3 complex (10 mol %) as catalysts, resulting in high enantioselectivities (83% to >98% ee (exo)) along with relatively good exo-selectivities (exo:endo = 65:35 to 94:6) and yields (63-85%). For the five-membered cyclic carbonyl ylide derived from 1-diazo-2,4-pentandione precursor, the cycloaddition reaction with 5-bromo-1-methylindole was carried out in the presence of Rh2(OAc)4 (2 mol %) and the chiral Pybox-Ph2-Er(OTf)3 complex (30 mol %) as catalysts, resulting in relatively good enantioselectivity (78% ee) and endo-selectivity (endo:exo = 81:19).

The title transformation consists of (i) reduction of the amide carbonyl group, (ii) formation of an iminium ion with an acid, and (iii) C—C bond formation with a mild nucleophile.

The dipyrrins (IV) obtained show a clear color change from red to blue when exposed to Broensted acids.

Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials—both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules.

The diastereo- and enantioselective formation of 3-arylaziridine-2-carboxylates from aryl aldehydes and guanidinium ylides is investigated.

Pyrolysis of the title compound 3 at 400 °C gave α-(2-hydroxyphenyl)-γ-butyrolactone (4) whose structure was confirmed by an alternative synthesis. A reaction mechanism via a phenyl ketene acetal is proposed.

In general, morphological, physiological, and biochemical properties of fungal cells are drastically different among solid-state (SSC), liquid-surface (LSC), and submerged cultivation (SmC) systems. In addition to these traditional cultivation systems, a unique liquid-surface cultivation [liquid-surface immobilization (LSI)] system and interface cultivation systems [extractive liquid-surface immobilization (Ext-LSI) system; liquid–liquid interface bioreactor (L–L IBR)] bring some interesting fungal morphological, physiological, and biochemical characteristics. The unique properties of fungal cells located on a liquid-surface and an organic–aqueous interface are very important to application of fungi to the production of enzymes, metabolites, and bioconversion products. In this review, the unique and important characteristics of fungal cells immobilized in the LSI, L–L IBR, and Ext-LSI systems are explained in detail. Moreover, some application of the cultivation systems to fermentation, enzyme production, and microbial transformation are introduced.

The title synthesis proceeds with high syn-diastereoselectivity and realized installation of halogen atoms (Br, Cl, F) into the α-position of carbonyl compounds.

The super silyl group Si(SiEt3)3 is found to be an efficient and robust protecting group for carboxylic acids.

[via [4 + 3] cycloaddition of (I) with an oxyallyl species generated from dibromopentanone (II) as the crucial step].

Intramolecular charge-transfer interactions in CH2Cl2 and redox behavior of the novel compounds [(V), (VI), (VIII), and (XI)] are investigated.

Pyrrolines (I) react with arylaldehyde acetals (II) in the presence of a Lewis acid and base to give arylmethylidene pyrrolines (III).

o-Alkynylanilines bearing a suitable leaving group (generally o-fluorobenzoyl) at the nitrogen are coupled with oxadiazoles to produce N-unsubstituted indoles directly.

Direct allylation of inert amide carbonyls utilizing the Schwartz reagent afforded either substituted tertiary or secondary amines. A preactivation step was successfully avoided, which is generally a requisite to increase the electrophilicity of amides. The reaction exhibited remarkable functional group tolerance and proceeded even in the presence of methyl esters and nitro groups.

The method provides a new method to prepare various biologically important N-azolylindoles.

Title compounds (VII) and (VIII) are prepared via condensation of anhydrides with diaminonaphthalene (VI).

A decarboxylative intramolecular aziridination reaction of alkene-tethered isoxazol-5-ones with a palladium/phosphine catalyst gives N-fused bicyclic aziridines which readily react with various reagents to afford ring-opened pyrroline derivatives.

Borylation of arenesulfonates (I) with dialkoxyborane (II) proceeds in the presence of a combination of Pd(dba)2 and a phosphanoferrocene derivative as a versatile catalyst system to afford arylboronates (III) in good yields.

Preparation of magnetic metal-containing nickel–phosphorus (Ni–P) nanotubes by a template synthesis with advanced morphology-tunable and recyclable supramolecules and plausible application to anisotropic conduction polymer films using them as orientation and alignment-controllable magnetic conductive filler were introduced.

Since compounds (III) and (IV) exhibit a significant change in their absorption and emission spectra in the presence of certain metal cations, they could be potentially used as metal-cation sensors.

The compounds (III) and (VIII) are quantitatively converted to the corresponding compounds (IV) and (IX) by using NaOMe in MeOH.

The title system efficiently catalyzes the coupling of hydrophobic as well as hydrophilic aryl halides (I) in water.

Various types of title compounds are synthesized through a dianionic Claisen rearrangement as the key step followed by different deprotection modes.

Several novel disaccharides, e.g. derivatives (III)/(IV) and (VII)/(VIII), are readily prepared by scandium-catalyzed glycosidation of sugar alcohols with acetates (I) and (V).

Optically active lactones were synthesized by a novel asymmetric synthesis in which enantiotopic groups remote from a prochiral center were effectively discriminated. The cyclic diamide alcohols bearing a C 2 -chiral auxiliary, (+)-[1,1'-binaphthyl]-2,2'-diamine (4), were designed and prepared such that the hydroxyl group should attack preferentially at one of the two carbonyl groups. By the catalytic action of trifluoroacetic acid, the substrates 6a,b and 19 were smoothly converted to the lactones the configurations of which were determined to be R, S, and R, respectively

A new reducing agent ( 2j ) reduced the enone ( 4 ) to give 15( S )-allylic alcohol ( 5a ) with excellent regio- and stereoselectivity through a five membered ring transition state. Stereoselecrivity of this reaction will be explained based on the LUMO of the enone moiety. The resulting ( 5a ) was led to a carbacyclin.

The title compound 2, is synthesised via the valence isomer 6 and shows an electron affinity comparable to p-benzoquinone; it also has potential synthetic utility for dienes.

1,4-Conjugate addition of organocopper reagents to (o-substituted phenyl alkenyl ketone)chromium complexes 3 gave the corresponding addition products 4 and 5 , respectively, depending on the nature of “organocopper” with high stereoface differentiation. This reaction provides a method of remote stereocontrol in combination with stereoselective conversion of Cr(CO) 3 -complexed benzylic ketone to alkyl group.

A novel one-pot synthetic method was developed for the preparation of optically active cyanohydrin acetates. Racemic cyanohydrins were generated from aldehydes and acetone cyanohydrin by quinidine-catalyzed transhydrocyanation, and the resulting cyanohydrins 2a–j were then acetylated by lipase in a stereoselective manner using isopropenyl acetate as an acylating regent. A variety of aldehydes 1a–j were successfully transformed into the corresponding cyanohydrin acetates 3a–j having 47–95% e.e. without isolating the unstable cyanohydrins 2. Moreover, the reversible nature of base-catalyzed transhydrocyanation allows for in situ racemization of the unreacted cyanohydrins and concurrent kinetic resolution by lipase enabled the preparation of (S)-3b–d with 40–82% e.e. in more than 50% yield. Polymer-supported cinchona alkaloid was also used as a catalyst for this one-pot reaction and showed the comparable chemical and optical yield to that for the soluble monomeric alkaloid. The insoluble polymer and lipase w...

The title compound 1, a strained p-benzoquinone due to cyclobutene annelation, affords novel decarbonylated dimer 2, with unusual easiness, upon heating either at solid or in solution.

The dianion of 6,6-diphenylfulvene obtained by reduction with lithium metal was first characterized spectroscopically. Reduction of 6-dimethylamino-6-phenylfulvene also generated its dianion whose ...

at will. Although the capacity shown here compares more than well with, for example, a biological alternative method using the protein cellulasea [the amounts of timolol with optimal base-line separation were 18.9 and 19.9 pg/g of dry CSP, respectively (Figure 2), and in connection with the aforementioned polarimetric study of propranolol, with fair resolution but no base-line separation, 400 p g / g of dry CSP], work aimed at increasing the capacity of analogous imprinted polymers is in progress and will further increase the applicability of the technique for (semi)preparative isolation of pure enantiomers of compounds such as &blockers. However, we feel that already today the removal of contaminating small amounts of the nondesired enantiomer may be feasible on a technical scale with the described technique.

3-Bromo-1,1,1-trifluoropropan-2-one (2) reacted with thiourea and N-monosubstituted thioureas to give the corresponding 4-trifluoromethylthiazoles, respectively. In the reactions with N,N'-diphenylthiourea and thioamides, the considerably stable intermediates, 4-hydroxy-4-trifluoromethylthiazoline derivatives 7 and 8, were isolated. The reaction of ethyl 2-bromo-4,4,4-trifluoro-3-oxobutanoate (4) with thiourea was carried out under the gentle conditions to give both thiazole-5-carboxylate 10 and 4-hydroxythiazoline 11. The thiazole 10 was applied to the azo dye synthesis and the absorption maxima of thus obtained azo dyes were discussed.

The thermal and nickel-catalyzed cyclodimerization of the hexapentaene produced two types of [4]radialenes. The X-ray structural analysis of the thermal dimer has shown that the molecule has a pinwheel-like structure with the exactly planar central four-membered ring.