Facile and Efficient Method for the Debromination of vic-Dibromides to Alkenes with BiCl3/Ga System

BiCl₃/Ga was found to be a mild, efficient, and chemoselective system for the debromination of a series of functionally and structurally various vic-dibromides. A broad range of functional groups (ester, carboxy, aldehyde, methoxy, chloro, and ketone) was tolerated under the reaction conditions and only trans olefins were obtained in good yields.     

Mild and Efficient Deoxygenation of Amine‐N‐oxides with MoCl5/NaI System

The MoCl₅/NaI system was found to be a new reagent for deoxygenation of various amine‐N‐oxides to the corresponding amines in good to excellent yields under mild conditions.     

Mild and Efficient Deoxygenation of Amine-N-oxides with BiCl3/Indium System

The BiCl₃/indium system was found to be a new reagent for deoxygenation of various amine-N-oxides to the corresponding amines in good to excellent yields under mild conditions.     

Rhodium‐Catalyzed Oxidative C–H Activation/Cyclization for the Synthesis of Phosphaisocoumarins and Phosphorous 2‐Pyrones

Rhodium‐catalyzed cyclization of phosphinic acids and phosphonic monoesters with alkynes has been developed. The oxidative annulation proceeds with complete conversion of phosphinic acid derivatives and allowed the atom‐economic preparation of useful phosphaisocoumarins with high yield and selectivity. The reaction is tolerant of extensive substitution on the phosphinic acid, phosphonic monoester and alkyne, including halides, ketone, and hydroxyl groups as substituents. Furthermore, we found that alkenylphosphonic monoesters proceed to give a wide range of phosphorus 2‐pyrones through oxidative annulation with alkynes. Mechanistic studies revealed that C? H bond metalation was the rate‐limiting step.     

Enzyme Mimetic Active Intermediates for Nitrate Reduction in Neutral Aqueous Media

Nitrate is a pervasive aquatic contaminant of global environmental concern. In nature, the most effective nitrate reduction reaction (NRR) is catalyzed by nitrate reductase enzymes at neutral pH, using a highly‐conserved Mo center ligated mainly by oxo and thiolate groups. Mo‐based NRR catalysts mostly function in organic solvents with a low water stability. Recently, an oxo‐containing molybdenum sulfide nanoparticle that serves as an NRR catalyst at neutral pH was first reported. Herein, in a nanoparticle‐catalyzed NRR system a pentavalent Mo^V(=O)S₄ species, an enzyme mimetic, served as an active intermediate for the NRR. Potentiometric titration analysis revealed that a redox synergy among Mo^V?S, S radicals, and Mo^V(=O)S₄ likely play a key role in stabilizing Mo^V(=O)S₄, showing the importance of secondary interactions in facilitating NRR. The first identification and characterization of an oxo‐ and thiolate‐ligated Mo intermediates pave the way to the molecular design of efficient enzyme mimetic NRR catalysts in aqueous solution.     

Size‐Controlled Fabrication of Polyaniline Microfibers Based on 3D Hydrodynamic Focusing Approach

Owing to the relatively high conductivity and unique redox behavior, polyaniline (PANI) has been one of the most technologically promising conducting polymers. Although various methodologies have been developed, fabrication of PANI microfibers has been a challenging task owing to the poor solubility in most organic solvents. By taking advantage of a microfluidic technology and organic soluble acid labile t‐Boc‐protected PANI (t‐Boc‐PANI) as the conducting polymer precursor, fabrication of PANI microfibers in a size‐controlled manner is possible. Introduction of a THF solution containing t‐Boc‐PANI, and dodecylbenzenesulfonic acid (DBSA) as a core flow, and water as a sheath flow into a microfluidic channel with a 3D hydrodynamic focusing effect results in crystallization of the polymer fiber. By changing the flow rate, linear PANI microfibers that range from 16.2 to 39.4 μm in diameter are readily obtained.

     

Selective Lead Adsorption by Recombinant Escherichia coli Displaying a Lead-Binding Peptide

A highly specific lead-binding peptide ThrAsnThrLeuSerAsnAsn was displayed on Escherichia coli, and lead adsorption characteristics of the recombinant bacteria were investigated. Cell surface-displayed peptide was expressed under the control of an arabinose promoter using outer membrane protein C (OmpC_t) as an anchoring motif. The optimal induction period and arabinose concentration for the expression of peptide-fused OmpC_t were determined to be 2 h and 0.001 g/L, respectively. Selective adsorption of Pb²⁺ onto recombinant cells was verified with individual or combinatory use of four metal ions, Pb²⁺, Ni²⁺, Co²⁺, and Cu²⁺; the amount of bound Pb²⁺ onto the biosorbents was significantly higher than the other metal ions. The adsorption isotherm of recombinant cells for Pb²⁺ followed the Langmuir isotherm with a maximum adsorption loading (q _max) of 526 μmol/g dry cell weight.     

Symbol re-mapping method for improvement of TML-1 VLC coder

To improve the efficiency of variable length codeword (VLC) encoding in TML-1 for H.26L, the authors propose to adaptively change the mapping relationship between a symbol and its bit pattern in the VLC table, based on a local measurement of the symbol probability. Simulation results show that the proposed method gives a ~30 and 37% reduction in the average bit rate for macro block type and coded block pattern information, respectively