Enantioselective synthesis of tunable chiral pyridine–aminophosphine ligands and their applications in asymmetric hydrogenation
作者:Youran Liu、Fei Chen、Yan-Mei He、Chenghao Li、Qing-Hua Fan
DOI:10.1039/c9ob00770a
日期:——
ligands were enantioselectively synthesized based on chiral 2-(pyridin-2-yl)-substituted 1,2,3,4-tetrahydroquinoline scaffolds, which were obtained in high yields and with excellent enantioselectivities via ruthenium-catalyzed asymmetric hydrogenation of 2-(pyridin-2-yl)quinolines. The protocol features a wide substrate scope and mild reaction conditions, enabling scalable synthesis. These chiral
基于手性2-(吡啶-2-基)-取代的1,2,3,4-四氢喹啉骨架,对映选择性地合成了一个可调谐的手性吡啶-氨基膦配体的小型文库,该文库以高收率和优异的对映选择性通过钌催化的2-(吡啶-2-基)喹啉不对称氢化。该方案具有广泛的底物范围和温和的反应条件,可实现可扩展的合成。这些手性P,N配体已成功应用于Ir催化的基准烯烃和具有挑战性的七元环亚胺(包括苯并ze庚因和苯并二氮杂卓)的不对称加氢反应。在2,4-二芳基-3 H-苯并[ b ]氮杂和2,4-不对称氢化反应中,具有出色的对映和非对映选择性(高达99%ee和> 20:1 dr)和/或前所未有的化学选择性。二芳基-3 H-苯并[ b ] [1,4]二氮杂pine。
A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
作者:Vakhid A. Mamedov、Nataliya A. Zhukova、Victor V. Syakaev、Aidar T. Gubaidullin、Tat'yana N. Beschastnova、Dil'bar I. Adgamova、Aida I. Samigullina、Shamil K. Latypov
DOI:10.1016/j.tet.2012.10.045
日期:2013.1
A highly efficient and versatile method for the synthesis of quinoxalinederivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange
基于3-(苯并咪唑-2-基)喹喔啉-2(1 H)-与1,2-的环收缩,已开发出一种高效且通用的具有两个苯并咪唑片段的喹喔啉衍生物的合成方法。二氨基苯及其各种类型的取代和稠合衍生物。由于分子间和分子内过程,涉及桥联和相邻碳原子的大多数双-苯并咪唑基喹喔啉信号的几种形式之间的自缔合,质子交换,构象和/或互变异构交换,且NMR光谱中的苯并咪唑片段变宽。苯并咪唑片段与分子的喹喔啉核心之间的共轭作用比喹喔啉衍生物(10c)与其噻二唑[ f ]-(17)和吡咯并[ a ]-(19)环化了衍生物,导致整个分子的平面度更大。
A novel synthesis of bisthiosemicarbazones of pentane-2,4-dione
作者:C. N. O'Callaghan、Dermot Twomey
DOI:10.1039/j39670002400
日期:——
1,2-Bis-(1-methyl-3-oxobutylideneamino)ethane on treatment with thiosemicarbazides yields bisthiosemicarbazones of pentane-2,4-dione. It is suggested that reaction takes place via a 1,4-diazepine intermediate. 1,4-Diazepine derivatives yield similar bisthiosemicarbazones on reaction with thiosemicarbazides.
Application and developing of iron‐doped multi‐walled carbon nanotubes (Fe/MWCNTs) as an efficient and reusable heterogeneous nanocatalyst in the synthesis of heterocyclic compounds
Iron‐dopedmulti‐walledcarbonnanotubes (Fe/MWCNTs) is an efficient, ecofriendly and reusableheterogeneousnanocatalyst for the one‐pot synthesis of heterocycliccompounds including bis‐spiro piperidines, piperidines, dihydro‐2‐oxopyrroles, pyrazoles and diazepines at room temperature with good to excellent yields. The heterogeneousnanocatalyst was fully characterized by scanning electron microscopy
铁掺杂的多壁碳纳米管(Fe / MWCNTs)是一种高效,生态友好且可重复使用的多相纳米催化剂,用于在室温下单锅合成杂环化合物,包括双螺哌啶,哌啶,二氢-2-氧吡咯,吡唑和二氮杂s温度高到极好的产量。通过扫描电子显微镜(SEM),X射线衍射(XRD),电感耦合等离子体(ICP)和FT-IR分析充分表征了多相纳米催化剂。同样,所有制备的化合物的结构均通过1 H NMR表征,13C NMR,FT-IR,质谱(MS)和元素分析。这些规程的主要优点是温和且绿色的反应条件,较短的反应时间,清洁的反应,操作简单,易于纯化以及可重复使用的多相纳米催化剂的产率高至优异。将该催化剂循环十次而活性没有明显损失。
An Efficient Synthesis of 3H-1,5-Benzodiazepine Derivatives Catalyzed by Heteropolyacids as a Heterogeneous Recyclable Catalyst
作者:Majid M. Heravi、Samaheh Sadjadi、Hossein A. Oskooie、Rahim Hekmatshoar、Fatemeh F. Bamoharram
DOI:10.1002/jccs.200800125
日期:2008.8
3H-1,5-benzodiazepines were synthesized by the condensation of o-phenylendiamine and various 1,3-diketones in the presence of various heteropolyacid (HPA) catalysts under mild conditions in very good yields and with high selectivity.