A convenient and stereoselective synthesis of （Z）-allyl selenides via Sm/TMSCI system-promoted coupling of Baylis-Hillman adducts with diselenides

A simple and convenient procedure for stercoselective synthesis of （Z）-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCI system to form selemde anions, which then undergo SN2＇ substitution of Baylis-Hillman adducts to produce the （Z）-allyl selenides.     

氯化钙、氯化镁纯化有机玻璃裂解粗产品研究与比较

文章主要在实验室条件下对废旧有机玻璃裂解所制得甲基丙烯酸甲酯粗产品的纯化方法进行研究.研究了粗产品中分别加入氯化钙、氯化镁后对甲醇杂质含量以及添加量和作用时间对效果的影响情况.实验结果表明,加入氯化钙时,每25 ml甲基丙烯酸甲酯粗单体中加入1.0 g氯化钙、放置4 h后甲醇含量降至最少;加入氯化镁时,每25 ml甲基丙烯酸甲酯粗单体中加入0.5 g氯化镁、放置1 h后甲醇含量降至最少.     

THE REACTION MECHANISM STUDY OF C 60 IN CH 3CHCl 2BY PULSE RADIOLYSIS AND LASER PHOTOLYSIS

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｄｉｓｃｏｖｅｒｙｏｆｆａｃｉｌｅｌａｂｏｒａｔｏｒｙｓｙｎｔｈｅｓｉｓａｎｄｃｈａｒａｃｔｅｒｉｚａｔｉｏｎ１,２ｏｆＣ６０ｈａｓｔｒｉｇｇｅｒｅｄｉｎｔｅｎｓｉｖｅｉｎｔｅｒｅｓｔｉｎｅｘｐｌｏｒｉｎｇｉｔｓｂａｓ...     

4-苯基-2-丁酮及其加成物的合成

4-苯基-2-丁酮是重要的医药中间体.本合成在乙醇、乙酸、氯化苄为原料,在强酸的催化下,羧酸与醇作用生成酯,乙酸乙酯通过克莱森缩合,酸碱反应、亲核加成反应、消除反应、CH3COOH酸化得到乙酰乙酸乙酯,再与氯化苄合成4-苯基-2-丁酮,最后与焦亚硫酸钠合成2-羟基4-苯基2-磺硫钠.     

高纯度共轭亚油酸的制备及其转化过程的表观动力学特征

共轭亚油酸是一种具有多种生理活性和潜在应用前景的脂肪酸 .研究了可用于规模化生产的高纯度共轭亚油酸的合成方法及其纯化的工艺路线和条件 .以红花油为原料 ,通过脲包纯化、共轭化制备出纯度高达 95 %的共轭亚油酸 ,总收率在 4 8%以上 .并对以葵花油为原料的亚油酸转化为共轭亚油酸的反应动力学进行了研究 ,建立了其表观动力学模型 ,为工业设计提供了依据     

A convenient and stereoselective synthesis of (Z)-allyl selenides via Sm/TMSCl system-promoted coupling of Baylis-Hillman adducts with diselenides

INTRODUCTION Allyl selenides have drawn much attention as a class of important intermediates in organic synthesis. For example, they are useful synthetic precursors for the [1,3]- or [2,3]-sigmatropic rearrangements (Shar-pless and Lauer, 1972; Fujita et al., 1998; Carter and Bourland, 2000), allylic homocoupling reactions (Masugama et al., 1989), and various other chemical transformations (Shea et al., 1986; Back and Moussa, 2002; 2003). Generally, allyl selenides are synthe-sized fr…     

Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid： facile synthesis of （Z）-allyl iodides

Stereoselective transformation of Baylis-Hillman acetates I into corresponding （Z）-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate （[bmim]BF4） was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford （Z）-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.