抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The Golden Age of Transfer Hydrogenation

Bull. Chem. Soc. Jpn. への投稿のすすめ

Recent Advances of Catalytic Asymmetric 1,3-Dipolar Cycloadditions

Surface and interface control of noble metal nanocrystals for catalytic and electrocatalytic applications

http://www.rsc.org/suppdata/cc/c2/c2cc30281k/c2cc30281k.pdf

Highly efficient synthesis of aromatic azos catalyzed by unsupported ultra-thin Pt nanowires

A Highly Active Nano-Palladium Catalyst for the Preparation of Aromatic Azos under Mild Conditions

Catalytic hydrogenation (reduction) and dehydrogenation (oxidation) reactions are of fundamental importance in the synthesis of organic molecules. The hydrogenation of aldehydes/ketones and imines yields the corresponding alcohols and amines. In the reverse direction, dehydrogenation of alcohols and amines forms the corresponding aldehydes/ketones and imines. The catalytic hydrogenations and dehydrogenations of N-heterocycles are particularly important transformations, as both saturated and unsaturated heterocycles are important structural units in natural products and pharmaceuticals. Previous methods for the hydrogenation of N-heterocycles have been catalyzed with homogeneous precious-metal catalysts, such as Ir, Ru, Rh, and Mo. Those catalytic systems all exhibit high activity and selectivity, but separation of the catalyst from the reaction mixture is quite difficult, and amines in particular suffer from contamination by the heavy-metal ions. Heterogeneous catalysis has also been used for the hydrogenation of N-heterocycles. Liao and Shi used Pd nanoparticles supported on tannin-grafted collagen fibers as a recyclable catalyst for the hydrogenation of quinoline. This catalyst showed excellent catalytic activity at an initial hydrogen pressure of 2 MPa. Bianchini found that silica-supported Pd nanoparticles could catalyze the hydrogenation of 1,10-phenanthroline at 30 bar (1 bar = 100 kPa) of hydrogen. Raney-Ni can also be used as a catalyst for the hydrogenation of phenanthrolines with good to excellent yields under 27 bar hydrogen pressure. As encouraging as these results are, the process is not suitable for industrial production because of the high working pressure. It is also energy intensive and suffers from some safety issues. Therefore, the development of a heterogeneous metal catalyst with superior catalytic activity and reusability is a very attractive research target. Kobayashi reported that sub-nanometer-sized Pd clusters stabilized by random copolymers act as catalysts for the hydrogenation of quinoline to 1,2,3,4-terahydroquinoline under mild reaction conditions. Recently, Au/TiO2, [11] Rh/AlO(OH), and heterogeneous multimetallic nanoparticle catalysts (72 catalysts based on Rh, Pt, Ir, and Ru) supported on metal oxides were also screened. They also need high hydrogen pressure (more than 8 bar). Pd@OmpG-C3N4 [14] (OmpG = outer membrane protein G) is the best catalyst that has been reported for the hydrogenation of quinolones, and it shows high activity and selectivity under mild reaction conditions (1 bar hydrogen and 40–100 8C). Platinum oxide (PtO2) can also be used in the hydrogenation of N-heterocycles in good yields. However, the utilization of Pt-based catalysts has been less investigated, even though Pt is regarded as one of the best metal catalysts for hydrogen activation. Kobayashi successfully applied polymer-incarcerated Pt nanoparticles (<3 nm) to the catalytic hydrogenation of unsaturated compounds including heterocycles in good yields under mild reaction conditions [5 atm of hydrogen (1 atm = 101.3 kPa)] . Somorjai and Yang demonstrated that the structure of the nanomaterials can affect the selectivity of the reactions: Pt nanocubes were used as a catalyst for the hydrogenation of pyrrole, and they showed selectivity towards n-butylamine that was higher than that shown by nanopolyhedra. These reported Pt-based catalysts are highly active and selective, which encouraged us to explore Pt-based heterogeneous catalysts in the hydrogenation of N-heterocycles. The direct oxidation of saturated N-heterocycles is an equally important organic transformation, as the structure unit can be found in many biologically active natural products and pharmacologically active molecules. Pd/C as a commercial catalyst proved to be effective in the oxidation of 1,2,3,4-tetrahydroquinolines to quinolines under mild reaction conditions. Ru-based catalysts can also be used in the oxidation of N-heterocycles to provide the products in good to excellent yields. Pt has proved to be one of the best catalysts for oxidation and has also been used as a heterogeneous catalyst in the oxidation of saturated N-heterocycles. Kaneda et al. found that supported Cu nanoparticles can be used in the dehydrogenation of 1,2,3,4-tetrahydroquinoline at 150 8C with the evolution of hydrogen gas. This is good for hydrogen transformations with organic molecules. This catalyst also shows excellent catalytic activity and selectivity for the hydrogenation of quinoline, and it is the first catalytic system that can be used in the hydrogenation of quinoline and in the dehydrogenation of hydrogenated quinoline. However, oxidative dehydrogenation is also an important transformation of organic molecules, and to the best of our knowledge, no catalytic system has been reported that can be used as an effective cat[a] D. Ge, Dr. L. Hu, J. Wang, Prof. X. Li, F. Qi, Prof. J. Lu, Prof. X. Cao, Prof. H. Gu Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry, Chemical Engineering and Materials Science Soochow University, Suzhou 215123 (China) Fax: (+ 86) 512-65880905 E-mail : xqcao@suda.edu.cn hongwei@suda.edu.cn Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cctc.201300136.

Reversible Hydrogenation–Oxidative Dehydrogenation of Quinolines over a Highly Active Pt Nanowire Catalyst under Mild Conditions

Traditionally important in the pharmaceutical, agrochemical, and synthetic dye industries, C-N coupling has proved useful for the preparation of a number of valuable organic compounds. Here, a new method for the direct one-pot reductive C-N coupling from carbonyl and aromatic nitro compounds is described. Employing ultrathin platinum nanowires as the catalyst and hydrogen as the reducing agent, N-alkylamines were achieved in high yields. Debenzylation products were not detected after prolonged reaction times. Time-dependent analysis, ReactIR spectroscopy and DFT calculations revealed that the C-N coupling proceeded through a different mechanism than traditional "reductive amination." N-Alkylamines were directly obtained by intermolecular dehydration over platinum nanowires under a hydrogen atmosphere, instead of intramolecular water elimination and imine hydrogenation.

Lei Hu

Papers

Highly efficient synthesis of aromatic azos catalyzed by unsupported ultra-thin Pt nanowires

A Highly Active Nano-Palladium Catalyst for the Preparation of Aromatic Azos under Mild Conditions

Reversible Hydrogenation–Oxidative Dehydrogenation of Quinolines over a Highly Active Pt Nanowire Catalyst under Mild Conditions

Ultrathin platinum nanowire catalysts for direct C-N coupling of carbonyls with aromatic nitro compounds under 1 bar of hydrogen.

Highly efficient synthesis of N-substituted isoindolinones and phthalazinones using Pt nanowires as catalysts.