Enantioselective Hydrogenation of Imidazo[1,2-<i>a</i>
]pyridines
作者:Christoph Schlepphorst、Mario P. Wiesenfeldt、Frank Glorius
DOI:10.1002/chem.201705370
日期:2018.1.9
of tetrahydroimidazo[1,2‐a]pyridines by direct hydrogenation was achieved using a ruthenium/N‐heterocyclic carbene (NHC) catalyst. The reaction forgoes the need for protecting or activating groups, proceeds with complete regioselectivity, good to excellent yields, enantiomeric ratios of up to 98:2, and tolerates a broad range of functional groups. 5,6,7,8‐Tetrahydroimidazo[1,2‐a]pyridines, which are
使用钌/ N-杂环卡宾(NHC)催化剂,通过直接氢化完成对四氢咪唑并[1,2- a ]吡啶的对映选择性合成。该反应放弃了对保护基团或活化基团的需要,以完全的区域选择性,良好至优异的产率,高达98:2的对映体比例进行,并且耐受宽泛的官能团。5,6,7,8-四氢咪唑并[1,2一]吡啶,其在许多生物活性分子中发现,直接通过该方法获得的,其适用性是由几个功能性分子的(正式)合成证明。
Practical synthesis of β-oxo benzo[d]thiazolyl sulfones: Scope and limitations
In this paper, we discuss our new synthetic approach towards functionalized benzo[d]thiazolyl (BT) sulfones, based on the reunion of alkyl BT sulfones and various electrophiles (e.g. RâCOâX, ROâCOâX, RSâCOâX, TsâXâ¦). All important aspects of this coupling reaction, including relevant and undesirable side reactions, are evaluated by means of calculations and competitive experiments. The scope and limitations of this method are established.
Scope and Mechanistic Limitations of a Sonogashira Coupling Reaction on an Imidazole Backbone
作者:Alexander H. Sandtorv、Hans-René Bjørsvik
DOI:10.1002/ejoc.201500520
日期:2015.7
A Sonogashira couplingreaction method to join terminal alkynes to the imidazole backbone was developed and investigated. The method exhibits good functional group tolerance and provides target 4-alkynylated imidazoles in 70–93 % yield. The alkyne reagents were characterized by means of DFT calculations, from which electrostatic potential surfaces (EPS) were produced. A clear correlation between the
Palladium-Catalyzed Cross-Coupling of Electron-Poor Terminal Alkynes with Arylboronic Acids under Ligand-Free and Aerobic Conditions
作者:Ming-Bo Zhou、Wen-Ting Wei、Ye-Xiang Xie、Yong Lei、Jin-Heng Li
DOI:10.1021/jo101063p
日期:2010.8.20
Palladium-catalyzed cross-coupling reaction of terminal alkynes with arylboronicacids has been described. In the presence of Pd(OAc)2 and Ag2O, a variety of terminal alkynes, including electron-poor terminal alkynes, smoothly underwent the reaction with numerous boronic acids to afford the corresponding internal alkynes in moderate to good yields. Moreover, this methodology was applied to the synthesis
Nickel(II) induzierte C-C-verknüpfung zwischen kohlenmonoxid und alkinen unter erhalt der dreifachbindung
作者:Heinz Hoberg、Hans Josef Riegel
DOI:10.1016/s0022-328x(00)98511-5
日期:1983.1
Acetylene and 1-alkynes react with carbon monoxide under basic conditions (amines) with nickel(II) complexes. L2NiBr2 (L = Et2NH, (C6H5)3P), to give acetylencarboxamides with maintenance of the triple bond. Intermediates are isolated, characterised and a mechanism is proposed.
乙炔和1-炔烃在碱性条件下(胺)与一氧化碳反应,生成镍(II)配合物。L 2 NiBr 2(L = Et 2 NH,(C 6 H 5)3 P),得到维持三键的乙酰羧酰胺。对中间体进行了分离,表征并提出了一种机理。