Rapid and Easy Access to (E)-1,3-Enynes, 1,3-Diynes and Allenes Starting from Propargylic Acetals, Exploiting the Different Reactivity of Lithium and Mixed Lithium–Potassium Organometallic Reagents
The treatment of propargylicacetals with various lithium and mixedlithium–potassium Schlosser reagents, has allowed a one-pot synthesis of (E)-1,3-enynes, 1,3-diynes and allenes, depending on the reaction conditions and the selected base. Various reaction conditions were investigated in order to control the selectivity of the reactions and to obtain pure products. The metallation–elimination sequence
Highly Efficient Synthesis of <i>cis</i>-[3]Cumulenic Diols via Zirconocene-Mediated Coupling of 1,3-Butadiynes with Aldehydes
作者:Xiaoping Fu、Shasha Yu、Guoqin Fan、Yuanhong Liu、Yuxue Li
DOI:10.1021/om201125z
日期:2012.1.23
A highly efficient and convenient method for the monozirconation of silyl- or tert-butyl-substituted 1,3-butadiynes using the Negishi reagent has been developed. The resulting zirconium butadiyne complexes undergo two syn-SE2′ reactions with various aldehydes to yield the cis-[3]cumulenic diols with moderate to high diastereoselectivities. The silyl substituents at the butadiyne terminus show remarkable
已经开发出使用Negishi试剂的甲硅烷基-或叔丁基-取代的1,3-丁二炔单锆化的高效且方便的方法。所得的丁二烯锆配合物与各种醛进行两个syn-S E 2'反应,生成具有中等至高非对映选择性的顺式-[3]枯烯二醇。丁二炔末端的甲硅烷基取代基对非对映选择性具有显着影响。
Zirconium-Mediated Multicomponent Reactions of 1,3-Butadiynes with Ylidenemalononitriles to Form Functionalized 1,8-Naphthyridine and Cyclopenta[<i>b</i>]pyridine Derivatives
作者:Shasha Yu、Renhong Sun、Haoyi Chen、Xin Xie、Yuanhong Liu
DOI:10.1002/chem.201405899
日期:2015.1.19
Zirconocene‐mediated multicomponent reactions of 1,3‐butadiynes with ylidenemalononitriles in the absence or presence of CuCl have been developed. In the absence of CuCl, 1,3‐butadiyne couples with three molecules of ylidenemalononitriles to yield azazirconacycles bearing a hexahydro‐1,8‐naphthyridine skeleton with high stereoselectivity. In the presence of CuCl, cyclopenta[b]pyridine or cyclopenta[b]quinolin‐1‐one
在不存在或存在CuCl的情况下,已开发出由茂茂锆介导的1,3-丁二炔与亚甲基丙二腈的多组分反应。在没有CuCl的情况下,1,3-丁二炔与三个分子的亚甲基丙二腈偶合,生成具有六氢-1,8-萘啶骨架且具有高立体选择性的氮杂碳杂环。在氯化亚铜,环戊二烯并[存在b ]吡啶或环戊二烯并[ b ]喹啉-1-酮衍生物通过Zr中的转移金属化获得 C键与Cu C键作为键反应步骤。这些多米诺型反应继续进行具有高化学-选择性,区域选择性和/或立体选择性,并允许多个C形成 N和C C键在单个操作中。
Stereoselective synthesis of enynones via base-catalyzed isomerization of 1,5-disubstituted-2,4-pentadiynyl silyl ethers or their alcohol derivatives
作者:Jingjin Chen、Guoqin Fan、Yuanhong Liu
DOI:10.1039/c0ob00344a
日期:——
1,5-Disubstituted-2,4-pentadiynyl silylethers undergo smooth desilylative isomerization to afford cis-enynones as major products with moderate stereoselectivities in the presence of a catalytic amount of KOtBu or DBU. While the isomerization reactions of their alcohol derivatives catalyzed by KOH, KOtBu or NaH take place efficiently to produce trans-enynones with high stereoselectivities. These reactions
1,5-二取代的2,4-戊二炔基甲硅烷基醚经过顺式脱甲硅烷基化异构化反应,以顺式-乙炔酮为主要产物,并在催化量的二甲基甲酰胺存在下,具有中等的立体选择性。KO Ť卜 或者 DBU。而其醇衍生物的异构化反应是通过酸值, KO Ť卜 或者 碳酸氢钠有效地产生具有高立体选择性的反式-乙炔酮。这些反应为合成具有广泛取代基的烯酮提供了方便实用的途径。
Highly Stereoselective Synthesis of Trisubstituted cis-[3]Cumulenols from Alkynylated Oxatitanacycles in the Presence of Lewis acids
作者:Jingjin Chen、Yuanhong Liu
DOI:10.1021/om900941y
日期:2010.1.25
A highly efficient and stereoselective method for the synthesis of trisubstituted cis-[3]cumulenols via oxatitanacycles derived from titanium-mediated coupling of 1,3-butadiynes with aldehydes or ketones promoted by Lewis-acids is described.