Iridium-Catalyzed Enantioselective Hydrogenation of Oxocarbenium Ions: A Case of Ionic Hydrogenation

Ionic hydrogenation has not been extensively explored, but is advantageous for challenging substrates such as unsaturated intermediates. Reported here is an iridium-catalyzed hydrogenation of oxocarbenium ions to afford chiral isochromans with high enantioselectivities. A variety of functionalities are compatible with this catalytic system. In the presence of a catalytic amount of the Brønsted acid HCl, an α-chloroether is generated in situ and subsequentially reduced. Kinetic studies suggest first-order kinetics in the substrate and half-order kinetics in the catalyst. A positive nonlinear effect, together with the half kinetic order, revealed a dimerization of the catalyst. Possible reaction pathways based on the monomeric iridium catalyst were proposed and DFT computational studies revealed an ionic hydrogenation pathway. Chloride abstraction and the cleavage of dihydrogen occur in the same step.     

One-step method for preparing the experimental pure state in nuclear magnetic resonance

Quantum computing is an emerging and promising research field in modern quantum physics and is committed to accelerating traditional calculation processes using the principle of quantum mechanics[1,2].Several computation models have been proposed,including the circuit model[3],topologic quantum computation[4],adiabatic quantum computing[5],and duality quantum computing[6-8].Universal quantum computation generally includes a system initialization,evolutionary control,and a final-state readout[9],where the preparation of the initial state is a key step in the entire process.     

Domino Radical Addition/Oxidation Sequence with Photocatalysis: One‐Pot Synthesis of Polysubstituted Furans from α‐Chloro‐Alkyl Ketones and Styrenes

A new domino reaction has been developed that allows the combination of styrenes and α‐alkyl ketone radicals to afford a wide array of polysubstituted furans in good to excellent yields under mild and simple reaction conditions. The key to success of this novel protocol is the use of photocatalyst fac‐Ir(ppy)₃ and oxidant K₂S₂O₈. Mechanistic studies by a radical scavenger and photoluminescence quenching suggest that a radical addition/oxidation pathway is operable.     

超声筛查早期诊断婴儿发育性髋关节异常的临床管理

目的 了解鄞州区0~6月龄婴儿发育性髋关节异常（developmental dysplasia of hip,DDH）的流行病学特征，探讨DDH 的临床管理模式。方法 由鄞州区妇幼保健机构社区医师和鄞州区第二医院围生医生共同负责完成DDH 的临床初筛工作，可疑或异常者转儿科进一步检查，并予B 超筛查，对不同人群分别进行早期干预、复查、随访及骨盆正位X 线片检查，必要时转小儿骨科治疗。结果 2012 年5 月至2013 年5 月，共6 890 例0~6月龄婴儿进行髋关节B 超筛查，初筛阳性率5.73%（395/6 890），复查阳性率0.59%（34/5729）；月龄越小筛查阳性率越高，差异有统计学意义（P＜0.05）。新生儿及1~3月龄婴儿初筛阳性率高，但复查阳性率明显降低，差异有统计学意义（P＜0.05）；4~6月龄婴儿初筛及复查阳性率差异无统计学意义（P ＞0.05）。结论 鄞州区采取的社区门诊检查- 区医院儿科复查-B 超筛查及转诊治疗的管理模式，可作为基层推进DDH 的早发现和早治疗的有效手段。     

Visible‐light photocatalytic activity of Ag@MIL‐125(Ti) microspheres

Ag nanoparticle (NP)‐decorated MIL‐125(Ti) microspheres (Ag@MIL‐125(Ti)) were firstly fabricated via a facile hydrothermal and following photo‐reduction method. The photocatalysts were characterized using X‐ray diffraction, scanning and transmission electron microscopies, X‐ray photoelectron spectroscopy and UV–visible diffuse reflectance spectroscopy. The characterization results indicated that Ag NPs were dispersed on the surface of MIL‐125(Ti) microspheres, and the Ag NPs had a uniform diameter of about 40 nm. The composites exhibited excellent visible‐light absorption, due to the modification with the Ag NPs. The photocatalytic activity for the visible‐light‐promoted degradation of Rhodamine B was improved through the optimization of the amount of Ag loaded as a co‐catalyst, this amount being determined as 3 wt%. Additionally, studies performed using radical scavengers indicated that O₂^? and e^? served as the main reactive species. The catalyst can be reused at least five times without significant loss of its catalytic activity. Furthermore, a photocatalytic mechanism for degradation of organics over Ag@MIL‐125(Ti) is also proposed. Copyright © 2015 John Wiley & Sons, Ltd.