3-O-苄基-α-L-鼠李糖甲苷的2-位单酰化

研究了3-O-苄基-α-L-鼠李糖甲苷在化学量的氧化银存在下,与酰化剂乙酰氯以及苯甲酰氯的反应,实现了2-位羟基的选择性单酰化,收率分别为66%和68%.     

AlCl3-Catalyzed Directional Conversion of some Polycyclic Aromatics

1　 IntroductionIt is well known that coal is the main fossilresource and energy,butit is also the main pollu-tion source in the world. The conventional meth-ods of coal utilization such as combustion,car-bonization,liquefaction and gasification can ob-tain only fuel and other low value products.Allthese conversion processes of coal belong to fuelutilization. L arge amounts of dust,SOx,CO2 andNOx,which cause the environment to be worseand worse,are emitted due to the processes. Be-cause of …     

离子液体在Friedel-Crafts反应中的应用

综述了离子液体中的Friedel-Crafts酰基化和烷基化反应。     

AlCl3催化下合成1,2-蒽乙二酮

研究了以高活性Lewis酸无水三氯化铝(AlCl3)为催化剂,蒽和草酰氯为反应物合成1,2-蒽乙二酮的酰基化反应.用GC考察了不同反应条件对1,2-蒽乙二酮产率的影响,当蒽为1 mmol,草酰氯为2 mmol,AlCl3为4 mmol,溶剂为CS2(15 mL),反应温度为30 ℃,反应时间5 h的条件下,1,2-蒽乙二酮的产率最高,为83.8%.通过萃取、重结晶等方法得到了 1,2-蒽乙二酮纯品,用熔点测定、GC/MS、FT-IR和 1HNMR等分析测试手段鉴定了其结构.     

Concave reagents. 31. A Merrifield bound concave pyridine for the selective acylation of polyols

The concave pyridine 2a has been synthesized in 61% yield in two macrocyclization steps. After deprotection to give 2b , the concave pyridine has been attached to a Merrifield resin, and the resulting polymer 10 containing 0.3 mmol 2 /g has been used as a selective acylation catalyst for the addition of propane‐1,2‐diol ( 11 ) and the glucose derivative 14a to diphenylketene ( 12 ) to form selectively 2‐hydroxypropyl diphenylacetate ( 13a ) (selectivity 13a / 13b : 11:1) and methyl 4,6‐0‐benzylidene‐2‐diphenylacetyl‐α‐D‐gluco‐pyranoside ( 14b ), (selectivity 14b / 13c : 29:1), respectively. After successful applications in batch reactions, the selective addition of 11 to 12 has also been carried out in a flow reactor filled with the polymeric catalyst 10 .     

Synthesis and chemical modification of new epoxy resins containing alkylaminopyridines

A new series of epoxy resins containing 4‐(N,N‐dialkylamine)pyridines (DAAP) functionality was prepared by reaction of 4‐aminopyridine or/and aniline with epichlorohydrin. Then, hydroxyl groups in the polymeric chain underwent a chemical modification with acyl chloride. Modification of the side group and backbone of the chain resulted in an enhancement of solubility of the linear catalyst with catalyzed system and also led to an accelerated acylation. Here, acetylation of tert‐butyl alcohol was monitored by means of chromatographic analyses for determining the catalytic power of these polymeric catalysts. Catalytic activity of the modified linear poly(4‐aminopyridine‐epichlorohydrin‐aniline) was found to be more effective than that of DMAP, and catalytic activity of network polymers in a heterogeneous system was found to be somewhat lower than that of any of its linear analogs. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1101–1105, 1999     

Highly Regioselective,Lewis Acid-Free Electrophilic Aromatic Substitution

By appropriate choice of solid catalyst and stoichiometric reagent it is possible to develop alternative procedures for many electrophilic aromatic substitution reactions that avoid the need for Lewis acid catalysts such as aluminium chloride. Furthermore, the catalysts may be regenerated, the reactions may be more controlled, corrosive by-products may be avoided and the structural features of the solid may lead to much greater regioselectivity than with traditional Lewis acids. Examples where such benefits are found include nitration, chlorination, bromination and acylation. © 1997 SCI.     

Erbium(III) Triflate as an Extremely Active Acylation Catalyst

Erbium(III) triflate is a powerful catalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidic anhydrides {Ac₂O, (EtCO)₂O, [(CH₃)₃CO]₂O, Bz₂O, and (CF₃CO)₂O} without isomerisation of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity.     

丁二酸酐改性磷脂及其对脂质体稳定性的影响

研究了酰化改性磷脂对包封鱼腥草挥发油的脂质体稳定性的影响。采用单因素试验优选酰化改性磷脂的最佳工艺条件,以逆相蒸发搅拌超声法制备脂质体,过柱分离检测包封率,在-10℃、40℃和常温下放置24h后,通过离心沉淀测定检测稳定性,显微镜法观察形态。丁二酸酐酰化改性磷脂制备的脂质体比未改性的稳定,其中酰化率为77%的改性磷脂包封鱼腥草挥发油脂质体的综合性能较好,其平均粒径为97nm。     

Free Radical‐Mediated Acylation and Carboxylation Reactions

Radical acylations to prepare carbonyl compounds are described and focus on indirect acylation approaches using sulfonyl oxime ethers under tin‐mediated and tin‐free conditions. The efficiency of carboxylic acid derivatives as carbonyl group radical acceptors in radical acylation and carboxylation reactions is discussed.