Direct Nucleophilic Addition to N‐Alkoxyamides

While the synthesis of amide bonds is now one of the most reliable organic reactions, functionalization of amide carbonyl groups has been a long‐standing issue due to their high stability. As an ongoing program aimed at practical transformation of amides, we developed a direct nucleophilic addition to N‐alkoxyamides to access multisubstituted amines. The reaction enabled installation of two different functional groups to amide carbonyl groups in one pot. The N‐alkoxy group played important roles in this reaction. First, it removed the requirement for an extra preactivation step prior to nucleophilic addition to activate inert amide carbonyl groups. Second, the N‐alkoxy group formed a five‐membered chelated complex after the first nucleophilic addition, resulting in suppression of an extra addition of the first nucleophile. While diisobutylaluminum hydride (DIBAL‐H) and organolithium reagents were suitable as the first nucleophile, allylation, cyanation, and vinylation were possible in the second addition including inter‐ and intramolecular reactions. The yields were generally high, even in the synthesis of sterically hindered α‐trisubstituted amines. The reaction exhibited wide substrate scope, including acyclic amides, five‐ and six‐membered lactams, and macrolactams.     

One-step production of nanofibrillated bacterial cellulose (NFBC) from waste glycerol using Gluconacetobacter intermedius NEDO-01

A major by-product of biodiesel production is waste glycerol, which has numerous potential applications. In this study, we isolated a novel bacterium capable of producing cellulose from waste glycerol, and identified it as a novel strain (named NEDO-01) of Gluconacetobacter intermedius. Scanning electron microscopy revealed that the morphology of the pellicle produced by NEDO-01 was similar to that of cellulose produced by Gluconacetobacter hansenii ATCC23769. Furthermore, X-ray diffraction and solid-state nuclear magnetic resonance spectroscopic analyses suggested that cellulose produced by NEDO-01 had molecular and crystalline structures similar to those of cellulose produced by ATCC23769. After the optimization of cultivation conditions, NEDO-01 mediated the one-step production of nanofibrillated bacterial cellulose (NFBC) from waste glycerol in a medium supplemented with carboxymethyl cellulose. Transmission electron microscopic analysis revealed that the NFBC was composed of relatively uniform fibers with diameters of approximately 20 nm. NFBC was produced as uniform water suspensions, the yield of which was 3.4 g/L from cultivation in 7.5 L medium in a 10-L jar fermenter. The bioconversion of waste glycerol to NFBC, which has superior fluidity, moldability, and miscibility, has a wide variety of applications, including potential uses in the medical and materials engineering fields.     

Pheromone synthesis. Part 255: Synthesis and GC–MS analysis of pheromonal triacylglycerols of male Drosophila fruit flies

Pheromonal triacylglycerols and their analogs, 1A, 1B, 2A, 2B, 3A, 3B, and 3C, of male Drosophila fruit flies were synthesized and analyzed by GC–MS. Their GC retention times were found to be a reliable measure to analyze and identify these triacylglycerols with acetyl, oleoyl and tigloyl groups, although the stereo- and regioisomers of 1 (1A and 1B), 2 (2A and 2B), and 3 (3A, 3B, and 3C) could not be distinguished from each other by MS alone.     

Liquid–Liquid Equilibria for Extraction of Citrus Essential Oil Using Ionic Liquids

The object of this study was to measure the liquid–liquid equilibria (LLE) data of binary mixtures containing ionic liquids and citrus essential oil. We investigated linalool as the citrus essential oil, and 1-alkyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C _n MIM]⁺[TFSI]^?) as the ionic liquid. Firstly, the experimental apparatus and procedure for the LLE measurement of mixtures containing ionic liquids were verified by measuring the LLE of the binary mixture 1-hexyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C₆MIM]⁺[TFSI]^?) + 1-hexanol as a reference test system recommended by Marsh et al. (Pure Appl Chem 81:781–789, 2009). Next, the LLE data for IL + linalool were obtained, and the LLE data of two binary mixtures 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C₄MIM]⁺[TFSI]^?) or [C₆MIM]⁺[TFSI]^? + linalool were determined. The experimental LLE data were satisfactorily represented by the non-random two-liquid model.     

Pricing American options with uncertain volatility through stochastic linear complementarity models

We consider the problem of pricing American options with uncertain volatility and propose two deterministic formulations based on the expected value method and the expected residual minimization method for a stochastic complementarity problem. We give sufficient conditions that ensure the existence of a solution of those deterministic formulations. Furthermore we show numerical results and discuss the usefulness of the proposed approach.     

Non-Gaussian fluctuations resulting from power-law trapping in a lipid bilayer

Anomalous diffusion in lipid bilayers is usually attributed to viscoelastic behavior. We compute the scaling exponent of relative fluctuations of the time-averaged mean square displacement in a lipid bilayer, by using a molecular dynamics simulation. According to the continuous time random walk theory, this exponent indicates non-Gaussian behavior caused by a power-law trapping time. Our results provide the first evidence that a lipid bilayer has not only viscoelastic properties but also trapping times distributed according to a power law.     

An M2L4 molecular capsule with an anthracene shell: encapsulation of large guests up to 1 nm

A new M(2)L(4) molecular capsule with an aromatic shell was prepared using two Pd(II) ions and four bisanthracene ligands. The self-assembled capsule possesses a cavity with a diameter of ~1 nm that can encapsulate medium-sized spherical and planar molecules as well as a very large molecule (C(60)) in quantitative yields. The encapsulated guests are fully segregated and shielded from the external environment by the large anthracene panels.     

Direct arylation of polycyclic aromatic hydrocarbons through palladium catalysis

We have discovered that the combination of Pd(OAc)(2)/o-chloranil can catalyze the direct C-H bond arylation of polycyclic aromatic hydrocarbons (PAHs) with arylboroxins that occurs selectively at the K-region. The sequential integration of Pd-catalyzed direct arylation of PAHs and FeCl(3)-mediated cyclodehydrogenation is effective in rapidly extending a parent PAH π-system with high directionality.     

Catalytic asymmetric oxidation of cyclic dithioacetals: highly diastereo- and enantioselective synthesis of the S-oxides by a chiral aluminum(salalen) complex

Aluminum(salalen) complex 1 [salalen = half-reduced salen, salen = N,N'-ethylenebis(salicylideneiminato)] was found to be a highly efficient catalyst for asymmetric oxidation of cyclic dithioacetals in the presence of 30% hydrogen peroxide as an oxidant. In the reaction of a series of 2-substituted 1,3-dithianes bearing alkyl, alkenyl, alkynyl, and aryl groups as the substituent, the trans-monoxides were obtained in high yields with 19:1 → >20:1 dr (diastereomeric ratio) and 98-99% ee (enamtiomeric excess). The reaction of nonsubstituted 1,3-dithiane also proceeded in a highly enantioselective manner to give the monoxide with a small formation of the trans-1,3-dioxide, an overoxidation product. Five-membered 1,3-dithiolanes and seven-membered 1,3-dithiepanes also underwent oxidation to give monoxides with high diastereo- and enantioselectivity. It was found that the equilibrium between the two chairlike conformers of dithianes has relevance to the observed diastereoselectivity in the first oxidation process, and the dioxide formation in the oxidation of 1,3-dithiane and its stereochemistry also can be explained by the conformational equilibrium of the product monoxide.