A systematic study for the structures and properties of phosphorylated pulp fibers prepared under various conditions

Cellulose - A bleached softwood kraft pulp was phosphorylated with (NH4)2HPO4 and urea at 150 ℃ for 0‒40 min, and the structures and properties of the resulting...     

Catalytic Kinetic Resolution of Biaryl Compounds

Biaryl compounds with axial chirality are very common in synthetic chemistry, especially in catalysis. Axially chiral biaryls are important due to their biological activities and extensive applications in asymmetric catalysis. Thus the development of efficient enantioselective methods for their synthesis has attracted considerable attention. This Minireview discusses the progress made in catalytic kinetic resolution of biaryl compounds and chronicles significant advances made recently in catalytic kinetic resolution of biaryl scaffolds.     

Asymmetric Total Synthesis of (−)‐Kravanhin B

The first asymmetric total synthesis of kravanhin B has been accomplished with a linear reaction sequence of 13 steps starting from (R)‐(?)‐carvone. The synthesis features an intramolecular aldol cyclization to construct the desired cis‐fused decalin skeleton and an acid‐catalyzed dehydration and olefin isomerization to install the γ‐butenolide ring.     

Total Synthesis of (−)‐Pepluanol B: Conformational Control of the Eight‐Membered‐Ring System

The first total synthesis of the Euphorbia diterpenoid pepluanol B in both racemic and enantioenriched form involves 20 steps from a known bicyclic diol. This synthesis features an unprecedented bromo‐epoxidation to control the eight‐membered‐ring conformation. In addition, salient reactions for the construction of the tetracyclic backbone include a sterically challenging aldol reaction to establish the quaternary center, a ring closing metathesis (RCM) to forge the eight‐membered ring, and a diastereoselective cyclopropanation to assemble the embedded cyclopropane motif.     

拉胀聚合物

本文简要介绍了几种经特殊加工制成的拉胀高聚物，粗线条地描述了目前国际上对拉胀聚合物的拉胀机理或拉胀性的研究，并展望了拉胀高分子材料的研究和应用前景。     

Stereoselective Synthesis of 2‐Deoxyglycosides from Glycals by Visible‐Light‐Induced Photoacid Catalysis

The direct, photoacid‐catalyzed synthesis of 2‐deoxyglycosides from glycals is reported. A series of phenol‐conjugated acridinium‐based organic photoacids were rationally designed, synthesized, and studied alongside the commercially available phenolic catalyst eosin Y. In the presence of such a photoacid catalyst and light, synthetic glycals were activated and coupled with a range of alcohols to afford 2‐deoxyglycosides in good yields and with excellent α‐selectivity.     

Direct method of calculating the dynamic scattering spectrum

A method of obtaining the scattering spectrum that bypasses the need to solve for the configurational distribution function of the macromolecules is presented. It involves the direct calculation of averages that appear in the structure factor expression. Application of the method to Rouse coils recovers Pecora's classical results. The method is applied to obtain the coherent spectrum of a solution of “encapsulated” dumbbells for which the configurational distribution is not available.     

第一届世界华人青年化学家学术会议暨第三届全国青年化学家学术会议在京召开

第一届世界华人青年化学家学术会议暨第三届全国青年化学家学术会议在京召开魏高原,赵新生（北京大学化学与分子工程学院北京１００８７１）ＴｈｅＦｉｒｓｔＣｏｎｆｅｒｅｎｃｅｆｏｒＷｏｒｌｄｗｉｄｅＹｏｕｎｇＣｈｉｎｅｓｅＣｈｅｍｉｓｔｓａｎｄｔｈｅＴｈｉｒ...