In this report, we demonstrate that self-aggregation is an intrinsic problem of bifunctional organocatalysts, especially in the case when the substrates do not have functional groups which are able to bind strongly with catalyst. Due to their self-association phenomena, the enantioselectivity of bifunctional catalysts dramatically decreases with increasing catalyst concentration or decreasing temperature. Thus, when the substrate concentration is kept constant, the enantioselectivity of bifunctional catalysts dramatically increases with decreasing catalyst loading. The ee values obtained at different catalyst concentrations are fairly consistent with the diffusion coefficients (D) of the catalysts, strongly indicating that their degree of self-association plays a crucial role in determining their enantioselectivity.

The Strecker synthesis is one of the most facile methods to access racemic a-amino acids. However, feasible catalytic asymmetric Strecker reactions for the large-scale production of enantioenriched a-amino acids are rare. Here we report a scalable catalytic asymmetric Strecker reaction that uses an accessible chiral variant of oligoethylene glycol as the catalyst and KCN to generate a chiral cyanide anion. Various a-amido sulphone substrates (alkyl, aryl and heteroaryl) can be transformed into the optically enriched Strecker products, a-aminonitriles, with excellent yields and enantioselectivities. Moreover, the robust nature of the catalyst enables a 'one-pot' synthesis of enantiomerically pure a-amino acids starting from a-amido sulphones and simple catalyst recycling. These features can make this protocol easily adaptable to the practical synthesis of unnatural a-amino acids.

Graphene has recently been studied as a promising material to replace and enhance conventional electronic materials in various fields such as electronics, photovoltaics, sensors, etc. However, for the electronic applications of graphene prepared by various techniques such as chemical vapor deposition, chemical exfoliation, mechanical exfoliation, etc., critical limitations are found due to the defects in the graphene in addition to the absence of a semiconducting band gap. For that, many researchers have investigated the doped graphene which is effective to tailor its electronic property and chemical reactivity. This work presents a review of the various graphene doping methods and their device applications. As doping methods, direct synthesis method and post treatment method could be categorized. Because the latter case has been widely investigated and used in various electronic applications, we will focus on the post treatment method. Post treatment method could be further classified into wet and dry doping methods. In the case of wet doping, acid treatment, metal chloride, and organic material coating are the methods used to functionalize graphene by using dip-coating, spin coating, etc. Electron charge transfer achieved from graphene to dopants or from dopants to graphene makes p-type or n-type graphenes, respectively, with sheet resistance reduction effect. In the case of dry doping, it can be further categorized into electrostatic field method, evaporation method, thermal treatment method, plasma treatment method, etc. These doping techniques modify Fermi energy level of graphene and functionalize the property of graphene. Finally, some perspectives and device applications of doped graphene are also briefly discussed.

Concentration-independent high enantioselectivity in the dynamic kinetic resolution (DKR) of racemic azlactones affording chiral α-aminoesters has been achieved using self-association free thiourea-based dimeric cinchona alkaloid organocatalysts. Detailed experimental studies and single crystal X-ray analysis confirmed that these bifunctional organocatalysts I do not form H-bonded self-aggregates in either solution or solid state.

The surface of polyimide ͑PI͒ films before/after plasma surface treatment using a remote-type modified dielectric barrier discharge was investigated to improve the adhesion between the PI substrate and the metal thin film. Among the plasma treatments of the PI substrate surface using various gas mixtures, the surface treated with the N 2 /He/SF 6 /O 2 plasma showed the lowest contact angle value due to the high CvO bondings formed on the PI surface, while that treated with N 2 /He/SF 6 showed the highest contact angle value due to the high C-F x chemical bondings on the PI surface. Specifically, when the O 2 gas flow was varied from 0 to 2.0 slm in the N 2 ͑40 slm͒/He͑1 slm͒/SF 6 ͑1.2 slm͒/O 2 ͑x slm͒ gas composition, the lowest contact angle value of about 9.3°w as obtained at an O 2 gas flow of 0.9 slm. And it was due to the high content of oxygen radicals in the plasma, which leads to the formation of the highest CvO bondings on the PI surface. When the interfacial adhesion strength between the Ag film and PI substrate was measured after the treatment with N 2 ͑40 slm͒/He͑1 slm͒/SF 6 ͑1.2 slm͒/O 2 ͑0.9 slm͒ followed by the deposition of Ag, a peel strength of 111 gf/mm was observed, which is close to the adhesion strength between a metal and the PI treated by a low pressure plasma.