Efficient Allylation of Aldehydes Promoted by Carboxylic Acids
作者:Gui-long Li、Gang Zhao
DOI:10.1021/jo050186q
日期:2005.5.1
mediating the allylation of aldehydes with allytributyltin in different solvents. A novel, general, and practical method of allylation of aldehydes promoted by carboxylic acids under mild reaction conditions has been developed. Among them, p-nitrobenzoic acid afforded high to quantitative yields of the homoallylicalcohol products, and can be easily recovered after workup by aqueous HCl. Glyoxylic
已经筛选出各种羧酸以在不同溶剂中介导醛与烯丙基三丁基锡的烯丙基化。已经开发了在温和的反应条件下烯丙基化由羧酸促进的醛的新颖,通用和实用的方法。其中,对硝基苯甲酸提供了高至定量产率的均烯丙基醇产物,并且在用HCl水溶液处理后可以容易地回收。乙醛酸自催化烯丙基化,而无需添加任何其他助催化剂或催化剂,从而以高收率得到相应的烯丙基化产物。通过控制羧酸的酸度,可以调节醛的丁酰化的区域选择性。醛的crotylation生产的α-加合物作为主要产物,使用CF可以中等至良好的收率3 CO 2 H作为促进剂。还讨论了烯丙基化的可能机制。
Allylation of Aldehydes Promoted by the Cerium(III) Chloride Heptahydrate/Sodium Iodide System: the Dependence of Regio- and Stereocontrol on the Reaction Conditions
The cerium(III) chloride heptahydrate/sodium iodide complex (CeCl3 ⋅ 7 H2O/NaI) acts as a useful promoter in the carbon-carbonbond forming reaction by addition of allyltributylstannanes to aldehydes. The reaction of 2-butenyltributylstannane shows that the regio- and the stereochemical outcomes depend on the reaction conditions. When the promoter is adsorbed on a solid support (aluminum oxide), a
铈(III)七水合氯化/碘化钠复合物(加入CeCl 3 ⋅7 H 2 O / NAI)作为在碳-碳键形成通过加入allyltributylstannanes醛的反应的有用的启动子。2-丁烯基三丁基锡烷的反应表明区域和立体化学结果取决于反应条件。当促进剂吸附在固体载体(氧化铝)上时,在无溶剂条件下会观察到非常普遍的γ加合物形成。相反,当反应在乙腈作为溶剂中进行时,α-加合物占优势。在最后一种情况下,观察到完全的立体控制,以高几何纯度获得较不稳定的(Z)-异构体。
Silver Oxide as a Novel Catalyst for Carbon–Carbon Bond-forming Reactions in Aqueous Media
作者:Masaharu Ueno、Arata Tanoue、Shu Kobayashi
DOI:10.1246/cl.2010.652
日期:2010.6.5
Silver oxide was found to be an excellent catalyst for allylation reactions of allyltributyltins with aldehydes in aqueous media. Despite the very low solubility of silver oxide in the media, the reactions proceeded smoothly, and the catalyst was recovered and reused. When α-methyl-substituted allyltributyltin was used as the nucleophile, the corresponding α-adducts were obtained exclusively in high yields with good anti-selectivity. A reaction mechanism including transmetalation from tin to silver is proposed.
A Highly Active and General Catalyst for the Stille Coupling Reaction of Unreactive Aryl, Heteroaryl, and Vinyl Chlorides under Mild Conditions
作者:Dong-Hwan Lee、Yingjie Qian、Ji-Hoon Park、Jong-Suk Lee、Sang-Eun Shim、Myung-Jong Jin
DOI:10.1002/adsc.201300075
日期:2013.6.17
efficient and general catalyst in the Stillecouplingreaction of various aryl and heteroaryl chlorides with organostannanes. The results show that this catalytic system allows for the use of less reactive substrates such as deactivated or sterically hindered arylchlorides. A catalyst loading of 0.5 mol% was sufficient to achieve excellent performance under relatively mild reaction conditions. Furthermore
Palladium- and Platinum-Catalyzed Addition of Aldehydes and Imines with Allylstannanes. Chemoselective Allylation of Imines in the Presence of Aldehydes
Pd(II) or Pt(II) complexes (10 mol %) either at room temperature or at reflux, giving the corresponding homoallylic alcohols 3 in high to good yields. Among the catalysts examined, PtCl2(PPh3)2 gave the best result. No only allyltribitylstannane but also methallyl- and crotyltributylstannane could be utilized in this transition metal catalyzed reaction. Detailed mechanistic studies of the Pd(II)-catalyzed