Preparation and characterization of magnetically separable MgFe<sub>2</sub>
O<sub>4</sub>
/Mg(OH)<sub>2</sub>
nanocomposite as an efficient heterogeneous catalyst for regioselective one-pot synthesis of β-chloroacetates from epoxides
Magneticallyseparable MgFe2O4/Mg(OH)2 nanoparticles were fabricated and characterized using various techniques. These nanoparticles were used as a new catalyst for regioselective one‐pot synthesis of β‐chloroacetates fromepoxides in the presence of NiCl2⋅6H2O and acetic anhydride. All reactions were carried out in ethanol at room temperature within 22–80 min giving the β‐chloroacetates in high to
磁分离MgFe 2 O 4 / Mg(OH)2纳米粒子的制备和表征使用各种技术。这些纳米颗粒被用作用于从氯化镍的存在下环氧化物区域选择性一锅合成β-氯乙酸的新的催化剂2 ⋅6H 2 O和乙酸酐。所有反应均在室温下于乙醇中进行22–80分钟,从而使β-氯乙酸盐的收率高至优异。使用外部磁体可以轻松分离纳米催化剂,并重复使用几次,而不会明显降低效率或磁性。
Efficient and Regioselective Conversion of Epoxides into Vicinal Chloroesters with TiCl4 and Imidazole in Ethyl Acetate
作者:N. Iranpoor、B. Zeynizadeh
DOI:10.1039/a800145f
日期:——
Epoxides can be cleaved easily in EtOAc with TiCl4 in the presence of imidazole to afford β-chloroesters with excellent yields and regioselectivity.
Organomercury/aluminum-mediated acylative cleavage of cyclic ethers
作者:Frederick A. Luzzio、Rhiana A. Bobb
DOI:10.1016/s0040-4020(98)01226-5
日期:1999.2
tetrahydrofurans are cleaved with concomitant acylation to chloroalkyl esters using a reagent system composed of an organomercurial, aluminum metal and an acid chloride. The cleavage is promoted under mild conditions by a range of readily-available cyclic β-alkoxychloromercurials and acid chlorides. Using mainly tetrahydrofuran and cyclohexene oxide as substrates, the yield of isolated chloroesters ranged from 52
Regio and stereocontrolled synthesis of aryl cis aminoalcohols from cis glycols
作者:Mahesh K. Lakshman、Barbara Zajc
DOI:10.1016/0040-4039(96)00334-6
日期:1996.4
Reaction of aryl substituted cis diols with α-acetoxyisobutyryl chloride results in the formation of trans vicinal chlorohydrin acetates where the halide is benzylic. Displacement of chloride with azide ion, deprotection of the ester and reduction of the azide furnishes the requisite cis aminoalcohols. This facile four-step procedure results in the exclusive replacement of a benzylic hydroxyl with