亚芳基亚乙烯基(五羰基)铬和钨配合物[(CO)5 M C C(C 6 H 4 R 1 - p)R 2 ](M = Cr,W; R 1 = H; R 2 = Me,C 6 H 4 R 3 - p [R 3 = H,Me,OMe,Cl,t Bu]; R 1 = Me; R 2 = C 6 H 4 Cl- p)与烷氧基乙炔HC⋮COR'(R'= Et ,ŤBu,金刚烷基),通过将CC三键加到亚乙烯基配体上的1,3-和环扩环得到氮杂亚烯基络合物。当使用单取代和不对称的双取代的双(芳基)亚乙烯基络合物时,获得两种异构体的混合物。在两个异构体中,取代基要么连接到七元环上,要么位于苯基的对位。通常,反应的选择性低。根据金属和取代基的不同,异构体的比率在0.5和2之间变化。对反应机理的DFT计算表明,反应通过亲核加成中的烷氧基乙炔与金属结合的C中的末端碳原子的引发α亚乙烯基配体的原子。反应的低选择性符合计
Preparation of 1,2,5-Trisubstituted 1<i>H</i>-Imidazoles from Ketenimines and Propargylic Amines by Silver-Catalyzed or Iodine-Promoted Electrophilic Cyclization Reaction of Alkynes
作者:Xiaorong Zhou、Zheng Jiang、Lexing Xue、Ping Lu、Yanguang Wang
DOI:10.1002/ejoc.201500704
日期:2015.9
From readily available propargylic amines, 1,2,5-trisubstituted imidazoles are efficiently obtained through a cascade reaction catalyzed by AgOTf or promoted by molecular iodine. The AgOTf-catalyzed reaction involves nucleophilic addition of propargylic amine to ketenimine, a silver-catalyzedelectrophiliccyclizationreaction of alkyne, and a tautomerism/isomerism/metal-H exchange cascade. The iodine-mediated
Rh-Catalyzed Annulations of <i>N</i>-Methoxybenzamides and Ketenimines: Sterically and Electronically Controlled Synthesis of Isoquinolinones and Isoindolinones
作者:Xiaorong Zhou、Zhiyin Zhang、Hongyang Zhao、Ping Lu、Yanguang Wang
DOI:10.1021/acs.joc.7b00258
日期:2017.4.7
Rhodium-catalyzedC–Hactivation/annulationreactions of ketenimines with N-methoxybenzamides are reported. The outcome of reactions is dependent on the structure of ketenimines. The β-alkyl-substituted ketenimines furnish 3-iminoisoquinolin-1(2H)-ones in a formal [4 + 2] annulation manner, while the β-ester substituted ketenimines afford 3-aminoisoindolin-1-ones in a formal [4 + 1] annulation manner
Unprecedented Formation of Azulenylidene Ligands by Reaction of the Vinylidene Ligand in Arylvinylidene Pentacarbonyl Complexes of Chromium and Tungsten with Alkoxyacetylenes
the selectivity of the reactions is low; the isomeric ratio varies between 0.5 and 2 depending on the metal and the substituent. DFT calculations on the reaction mechanism indicate that the reactions are initiated by a nucleophilic addition of the terminal carbon atom of the alkoxyacetylene to the metal-bound Cα atom of the vinylidene ligand. The low selectivity of the reactions is in accord with the
亚芳基亚乙烯基(五羰基)铬和钨配合物[(CO)5 M C C(C 6 H 4 R 1 - p)R 2 ](M = Cr,W; R 1 = H; R 2 = Me,C 6 H 4 R 3 - p [R 3 = H,Me,OMe,Cl,t Bu]; R 1 = Me; R 2 = C 6 H 4 Cl- p)与烷氧基乙炔HC⋮COR'(R'= Et ,ŤBu,金刚烷基),通过将CC三键加到亚乙烯基配体上的1,3-和环扩环得到氮杂亚烯基络合物。当使用单取代和不对称的双取代的双(芳基)亚乙烯基络合物时,获得两种异构体的混合物。在两个异构体中,取代基要么连接到七元环上,要么位于苯基的对位。通常,反应的选择性低。根据金属和取代基的不同,异构体的比率在0.5和2之间变化。对反应机理的DFT计算表明,反应通过亲核加成中的烷氧基乙炔与金属结合的C中的末端碳原子的引发α亚乙烯基配体的原子。反应的低选择性符合计
Base-mediated regioselective [3+2] annulation of ketenimines and isocyanides: efficient synthesis of 1,4,5-trisubstituted imidazoles
作者:Jinxiong Cai、Haijie Bai、Yuan Wang、Xianxiu Xu、Haiming Xie、Jun Liu
DOI:10.1039/c9cc01257e
日期:——
A novel base-mediated regioselective [3+2] annulation of active methylene isocyanides with ketenimines has been developed.