Reductive Cross‐Coupling of Conjugated Arylalkenes and Aryl Bromides with Hydrosilanes by Cooperative Palladium/Copper Catalysis

A method for the reductive cross‐coupling of conjugated arylalkenes and aryl bromides with hydrosilanes by cooperative palladium/copper catalysis was developed, thus resulting in the highly regioselective formation of various 1,1‐diarylalkanes, including a biologically active molecule. Under the applied reaction conditions, high levels of functional‐group tolerance were observed, and the reductive cross‐coupling of internal alkynes with aryl bromides afforded trisubstituted alkenes.     

A Transformable and Bulky Methacrylate Monomer That Enables the Synthesis of an MMA-nBA Alternating Copolymer: Sequence-Dependent Self-Healing Properties

In this study, we designed a methacrylate molecule with an alkyl-substituted trichloro salicylic acid pendant as a transformable bulky monomer to enable the synthesis of an alternating copolymer of methyl methacrylate (MMA) and n-butyl acrylate (nBA). The adamantyl-substituted methacrylate monomer ( 1-Ad ) showed very low homopolymerization propensity in radical polymerizations, but afforded the alternating copolymer with nBA via copolymerization. The 1-Ad units in the resultant copolymer were quantitatively and selectively transformed into MMA via transesterification with methanol to yield the alternating copolymer of MMA and nBA. Its alternating sequence was clearly demonstrated by a structural analysis via ¹³C NMR spectroscopy as well as the low reactivity ratios for the 1-Ad and nBA pair. Finally, we verified the superior self-healing ability of the alternating copolymer compared to that of the corresponding 1 : 1 statistical copolymer.     

Selective synthesis of secondary and tertiary amines by cp*iridium-catalyzed multialkylation of ammonium salts with alcohols

The efficient selective synthesis of secondary and tertiary amines has been achieved by means of Cp*Ir-catalyzed multialkylation of ammonium salts with alcohols without solvent: the reactions of ammonium acetate with alcohols gave tertiary amines exclusively, while those of ammonium tetrafluoroborate afforded secondary amines selectively. Using this method, secondary 5- and 6-membered cyclic amines were synthesized from ammonium tetrafluoroborate and diols in one pot.     

Benzonorcorrole NiII Complexes: Enhancement of Paratropic Ring Current and Singlet Diradical Character by Benzo‐Fusion

Fused benzene rings to antiaromatic compounds generally improve their stability but attenuate their antiaromaticity. The opposite case is now reported. Ni^II benzonorcorroles were synthesized and the effect of benzo‐fusion on the antiaromaticity was elucidated. The benzo‐fusion resulted in significant decrease of the HOMO–LUMO gaps and enhancement of the paratropic ring current effect. Furthermore, the introduction of the benzo groups induced singlet diradical character in the antiaromatic porphyrinoid.     

Production of optically pure d-lactic acid by Nannochlorum sp. 26A4

Microalgae were screened from seawater for greenhouse gas CO₂ fixation and d-lactic acid production by self-fermentation and tested for their growth rate, starch content, and conversion rate from starch into d-lactic acid. More than 300 strains were isolated, and some of them were found to have suitable properties for this purpose. One of the best strains, Nannochlorum, sp. 26A4, which was isolated from Sakito Island, had a starch content of 40% (dry weight), and a conversion rate from consumed starch into d-lactic acid of 70% in the dark under anaerobic conditions. The produced d-lactic acid showed a high optical purity compared with the conventional one. The proposed new d-lactic acid production system using Nannochlorum sp. 26A4 should also be an effective technology for greenhouse gas CO₂ fixation and/or conversion into industrial raw materials.     

Characterization of Benzo[a]naphtho[2,3-f]pentalene: Interrelation between Open-shell and Antiaromatic Characters Governed by Mode of the Quinoidal Subunit and Molecular Symmetry

The singlet open-shell character and antiaromaticity are intriguing features in π-conjugated carbocycles. These two exhibit similar chemical and physical properties. However, they rarely coexist in the same molecule. Understanding the interrelation between the open-shell and antiaromatic characteristics in the same molecule is crucial to control the electronic properties. Herein we describe the synthesis and characterization of a new member of diareno[a,f]pentalene, benzo[a]naphtho[2,3-f]pentalene 6 . Unlike its isomer 5 with a closed-shell ground state, 6 exhibits an appreciable open-shell character and a moderate antiaromatic feature. The behaviors of the open-shell index (y₀) against the difference of the proton chemical signal (Δδ(H¹)) between pentalenide dianions/neutral pentalenes for our reported pentalenes 1 , 4 , 5 , and 6 give a thought-provoking conclusion about the interrelation between open-shell and antiaromatic characteristics in this series. The mode of the incorporated quinoidal moiety and the formal molecular symmetry are critical to balance these two characteristics.     

Dissociated neuronal culture expressing ionotropic odorant receptors as a hybrid odorant biosensor--proof-of-concept study

Artificial odorant sensors generally perform poorer than olfactory systems in living organisms. The excellent performances of living odorant systems are achieved by the molecular recognition abilities of odorant receptors and the neuronal information processing that follows. To take advantages of this, here we propose a novel hybrid odorant biosensor by means of expressing ionotropic odorant receptors of insects into dissociated neuronal cultures of rodents. This combination of materials brings significant advantages such as easy functional expression, prolonged lifetime, and an ability to amplify the weak ionic currents of odorant receptors. In the present work, pheromone receptors and co-receptors of silkmoth, i.e., BmOR1 and BmorOrco, were expressed in neuronal cultures via liposome transfection. Consequently, BmOR1 and BmorOrco were co-expressed in 8% of neuronal cells, and both receptors were co-localized on a cell membrane. In Ca++ imaging experiments, synchronous increase of calcium signals at the presentation of BOL was found in both transfected cells and non-transfected cells in a dose-dependent manner. These results provide the proof-of-concept of the proposed hybrid odorant biosensor.     

Component Crystallization and Physical Collapse during Freeze-Drying of L-Arginine-Citric Acid Mixtures

Component crystallization and physical collapse during freeze-drying of aqueous solutions containing protein-stabilizing L-arginine and citric acid mixtures were studied. Freeze-drying microscopy (FDM) and thermal analysis of the solute-mixture frozen solutions showed collapse onset at temperatures (T(c)) approximately 10°C higher than their T(g)'s (glass transition temperatures of the maximally freeze-concentrated solute phase). Experimental freeze-drying of these solutions at a low chamber pressure showed the occurrence of physical collapse at shelf temperatures close to or slightly higher than the T(c). Slower ice sublimation at higher chamber pressures induced the physical collapse from lower shelf temperatures. The large effect of chamber pressures on the collapse-inducing shelf temperatures confirmed significance of the sublimation-related heat loss on the sublimation interface temperature during the primary drying. Drying of the single-solute L-arginine solution resulted in cake-structure solids composed of its anhydrous crystal. Thermal and powder X-ray diffraction (PXRD) analysis suggested slow crystal nucleation of L-arginine dihydrate in the frozen solutions. Characterization of the frozen solutions and freeze-dried solids should enable rational formulation design and process control of amino acid-containing lyophilized pharmaceuticals.     

Controlled Positioning of Activated Ester Moieties on Well‐Defined Linear Polymer Chains

The successful sequence‐controlled installation of an activated ester using a newly designed monomer pentafluorophenyl 4‐maleimidobenzoate is demonstrated. Pentafluorophenyl 4‐maleimidobenzoate is kinetically installed at different stages of a nitroxide‐mediated polymerization, namely, near the α‐chain end and in the middle of a PS chain. In addition, successful installation of apolar and polar functional groups is achieved via post‐polymerization functionalization, which demonstrated the versatility of the synthesis of a universal precursor for locally functionalized polymers.