Strictly Regiocontrolled α-Monosubstitution of Cyclic Carbonyl Compounds with Alkynyl and Alkyl Groups via Pd-Catalyzed Coupling of Cyclic α-Iodoenones with Organozincs
derivatives readily undergo Pd-catalyzed cross coupling with α-iodoenones. Although (s-Bu)2Zn also undergoes Pd-catalyzed cross coupling, only the n-Bu-substituted products were obtained. α-Benzylation and α-homobenzylation can proceed satisfactorily, whereas allylzinc and propargylzinc derivatives undergo only addition to the carbonyl group. Although some promising results have been obtained in α-homoallylation
Mechanism of a No-Metal-Added Heterocycloisomerization of Alkynylcyclopropylhydrazones: Synthesis of Cycloheptane-Fused Aminopyrroles Facilitated by Copper Salts at Trace Loadings
作者:Sidney M. Wilkerson-Hill、Diana Yu、Phillip P. Painter、Ethan L. Fisher、Dean J. Tantillo、Richmond Sarpong、Jason E. Hein
DOI:10.1021/jacs.7b06007
日期:2017.8.2
heterocycloisomerization reaction that forms annulated aminopyrroles is presented. Density functional theory calculations and kinetic studies suggest the reaction is catalyzed by trace copper salts and that a Z- to E-hydrazone isomerization occurs through an enehydrazine intermediate before the rate-determining cyclization of the hydrazone onto the alkyne group. The aminopyrrole products are obtained in 36-93% isolated
介绍了形成环氨基吡咯的新杂环异构化反应的机理研究。密度泛函理论计算和动力学研究表明,该反应是由痕量铜盐催化的,并且在腙到炔基上的限速环化之前,通过烯肼中间体发生 Z 到 E 腙异构化。取决于炔基取代基的性质,以36-93%的分离产率获得氨基吡咯产物。开发了一种新的自动采样技术以获得可靠的机械数据。
Silver(I)-Mediated Cascade Reaction of 2-(1-Alkynyl)-2-alken-1-ones with 2-Naphthols
efficient cascade reaction of 2-(1-alkynyl)-2-alken-1-ones with 2-naphthols promoted by silver trifluoroacetate is disclosed, providing an expeditious access to 1,2-dihydronaphtho[2,1-b]furans with moderate to good yields. This domino process involves highly regio- and diastereoselective sequential cyclization/nucleophilic addition/oxidative ring opening/oxa-Michael addition reactions to construct three
公开了由三氟乙酸银促进的2-(1-炔基)-2-链烯-1-酮与2-萘的有效级联反应,提供了快速接触1,2-二氢萘并[2,1- b ]呋喃的途径。中等至良好的产量。该多米诺过程涉及高度区域和非对映选择性的连续环化/亲核加成/氧化性开环/ oxa-Michael加成反应,以构建三个新的化学键和一个新的五元环。还提出了克级实验和开发不对称变体的初步结果,以显示当前反应的实用性和潜力。
Addition of Primary Amines to 2-(1-Alkynyl)-2-cycloalken-1-ones
The regio‐ and stereoselective nucleophilicaddition of primary aliphatic amines to 2‐(1‐alkynyl)‐2‐cycloalken‐1‐ones proceeds through double‐bond migration. In particular, (Z)‐β‐enaminones having cycloalkene rings can be prepared through a mild and atom‐economical route.
Access to functionalized alkynylcyclopropanes <i>via</i> reductive radical-polar crossover-based reactions of 1,3-enynes with alkyl radicals
作者:Beibei Zhang、Junfei Luo、Yewen Fang
DOI:10.1039/d2ob02155b
日期:——
radical-polar crossover process as a strategy, protocols dealing with the preparation of functionalized alkynylcyclopropanes have been successfully developed via the reactions of 1,3-enynes with alkylradicals. In addition to redox-neutral photocatalysis, nickel catalysis with zinc as the reductant is also an alternative to enable reactions of 1,3-enynes with redox-active N-hydroxyphthalimide esters