Synthesis of novel amphiphilic pyridinylboronic acids

Novel 3‐alkoxy‐2‐pyridinylboronic acids bearing, in their 3‐position, linear alkoxy or perfluoroalkoxy chains with n carbon atoms (n = 6, 8, 10, 12 and 18) 2a – 2g are synthesized from 2‐bromo‐3‐pyridinol, which is the common starting product. Our alternative procedure for the synthesis of 3‐alkoxy‐2‐bromopyridine in a phase‐transfer catalysis system is to carry out the reaction in a solid–liquid medium in the presence of a quaternary ammonium salt under microwave irradiation. General and versatile synthetic methods have been developed for preparation of a large variety of new 2‐pyridinylboronic acids bearing two alkylated or perfluoroalkylated side chains with an ether junction in the 3‐position. Copyright © 2003 John Wiley & Sons, Ltd.     

丙烯酸十六酯的合成

以对甲苯磺酸为催化剂、甲苯为溶剂和对苯二酚为阻聚剂,丙烯酸和十六酯通过直接酯化法合成了丙烯酸十六酯.实验结果表明,合成的最佳反应条件为：丙烯酸与十六酯的物质的量之比为1.2：1,对甲苯磺酸的用量为0.6%,对苯二酚的用量为0.4%,反应温度为110℃,反应时间为5 h.在此反应条件下,丙烯酸十六酯的产率可以达到98%,产品经IR光谱和^1HNMR光谱证实.     

Convergent synthesis of trans-fused 6/n/6/6 (n=7, 8) tetracyclic ether system via α-cyano ethers

A convergent method for synthesizing 6/n/6/6 (n=7, 8) tetracyclic ether system via two-rings construction of the central n/6 ring system was developed. The key steps of the present synthesis involve a ring-closing metathesis reaction for the construction of the seven- and eight-membered rings, and reductive etherification for the tetrahydropyrans. Unification of the two fragments through acetal formation, followed by regioselective cleavage of the acetal using TMSCN/TMSOTf in the presence of 2,6-di-tert-butyl-4-methylpyridine, afforded the α-cyano ether, of which the nitrile group was manipulated to give the precursors of the ring-closing reactions.     

氧化物对Hβ沸石催化行为的影响

用ＸＲＤ、ＸＰＳ“ＮＨ３－ＴＰＤ、ＦＴ－ＩＲ及化学吸附等手段研究了负载Ｂ２Ｏ３、Ｆｅ２Ｏ３等氧化物对Ｈβ沸石表面酸性和丙烯醚化反应性能的影响。结果表明：负载的Ｂ２Ｏ３、Ｆｅ２Ｏ３ｇｎ Ｈβ－Ａｌ２Ｏ３沸石间有较强的相互作用，Ｂ和Ｆｅ的化学环境有明显改变，氧化物调变了Ｈβ－Ａｌ２Ｏ３沸石的酸性，使总酸量增加，强酸中心强度下降，Ｌ酸中心比例提高，氧化物使丙烯醚化反应活性增强，抑制了异丙醇脱水反应、现烯     

相转移催化反应的研究——Ⅲ.季铵盐的结构与其催化性能的关系

选用了四种季铵盐作为相转移催化剂:三甲基苄基氯化铵,三乙基苄基氯化铵,三丙基苄基氯化铵,三丁基苄基氯化铵,应用于由邻硝基氯化苯合成邻硝基苯甲醚反应中,测定了它们的假一级反应速度常数和反应活化能,求得了反应的活化焓△H~+、活化熵△S~+和活化自由能△G~+。利用季铵盐所具有的有机和无机特性,研究了大小不同烷基的季铵盐相转移催化剂的结构与反应速度常数之间的关系,并且测得四种季铵盐在水-油两相中的平衡分配比。     

Cobalt-Catalysed Reductive Etherification Using Phosphine Oxide Promoters under Hydroformylation Conditions

A phosphine-oxide-promoted, cobalt-catalysed reductive etherification using syngas as a reductant is reported. This novel methodology was successfully used to prepare a broad range of unsymmetrical ethers from various aldehydes and alcohols containing diverse functional groups, and was scaled-up to multigram scale under comparably mild conditions. Mechanistic experiments support an acetalization–hydrogenation sequence.     

杂芳基烷基醚、杂芳基卤化物与(氘代)醇的亲核醚化

研究了在叔丁醇钾的作用下,杂芳基烷氧化合物、杂芳基卤化物和杂芳基硫醚与各种伯、仲、叔脂肪醇高效醚化,强调了天然产物和生物活性分子的衍生化以及不易通过其他途径获得的氘代芳基烷基醚的合成方法的实用性.