开发了 Ir 催化的喹啉不对称氢化反应,通过调节反应溶剂(甲苯/二恶烷:产率高达 99%,98% ee),可以分别以高产率和良好的对映选择性轻松获得手性四氢喹啉衍生物的两种对映异构体( R ),TON = 680;EtOH:高达 99% 的产率,94% ee ( S ),TON = 1680)。它为手性四氢喹啉的对映发散合成提供了一种有效且简单的合成策略,并且在这两个反应体系中,克级不对称加氢反应在低催化剂负载的情况下顺利进行。一系列氘标记实验、对照实验和1进行了H NMR和电喷雾电离-质谱实验,并在这些有用观察的基础上揭示了合理和可能的反应过程。
Manganese(I)-Catalyzed Transfer Hydrogenation and Acceptorless Dehydrogenative Condensation: Promotional Influence of the Uncoordinated N-Heterocycle
作者:Chong Zhang、Bowen Hu、Dafa Chen、Haiping Xia
DOI:10.1021/acs.organomet.9b00475
日期:2019.8.26
showed the highest activity. The reactions proceeded well with 0.5 mol % of catalyst loading and 20 mol % of t-BuOK at 85 °C for 24 h. Furthermore, 3 was also used as a catalyst for the synthesis of primary alcohols via transfer hydrogenation of aldehydes and the synthesis of 1,2-disubstituted benzimidazoles and quinolines via acceptorless dehydrogenative condensations.
四种二齿锰(I)配合物[(C 5 H 4 N-C 5 H 3 N-OH)Mn(CO)3 Br](1),[(C 9 H 6 N-C 5 H 3 N-OH)Mn(CO )3 Br](2),[(C 8 H 5 N 2 -C 5 H 3 N-OH)Mn(CO)3 Br](3)和[(C 8 H 5 N 2 -C 5 H 3 N-OCH 3)Mn(CO)3Br](4)被合成。测试了这些配合物作为酮转移氢化的催化剂,其中3种显示出最高的活性。在85℃下,在0.5mol%的催化剂负载量和20mol%的t- BuOK下,反应进行得很好,持续了24小时。此外,3还用作催化剂,用于通过醛的转移氢化合成伯醇,以及通过无受体的脱氢缩合反应合成1,2-二取代的苯并咪唑和喹啉。
Metal–Ligand Cooperative Approach To Achieve Dehydrogenative Functionalization of Alcohols to Quinolines and Quinazolin-4(3<i>H</i>)-ones under Mild Aerobic Conditions
作者:Siuli Das、Suman Sinha、Deepannita Samanta、Rakesh Mondal、Gargi Chakraborty、Paula Brandaõ、Nanda D. Paul
DOI:10.1021/acs.joc.9b01343
日期:2019.8.16
under relatively mild reaction conditions (≤90 °C) is reported. Simple and easy-to-prepare air-stable Cu(II) complexes featuring redox-active azo-aromatic scaffolds, 2-arylazo-(1,10-phenanthroline) (L1,2), are used as catalyst. A wide variety of substituted quinolines and quinazolin-4(3H)-ones were synthesized in moderate to good isolated yields via dehydrogenative coupling reactions of various inexpensive
Efficient Organoruthenium Catalysts for α‐Alkylation of Ketones and Amide with Alcohols: Synthesis of Quinolines
<i>via</i>
Hydrogen Borrowing Strategy and their Mechanistic Studies
for C−C bond formation and exhibited excellent performance in the dehydrogenative coupling of ketones and amides. In the synthesis of C–C bonds, alcohols were utilized as the alkylating agent. A broad range of substrates, including sterically hindered ketones and alcohols, were well tolerated under the optimized conditions (TON up to 47000 and TOF up to 11750 h−1). This ruthenium (II) catalysts were
Copper-catalyzed aromatic C–H bond halogenation with lithium halides under aerobic conditions
作者:Song Mo、Yamin Zhu、Zengming Shen
DOI:10.1039/c3ob40185e
日期:——
A concise and practical Cu-catalyzed protocol for the preparation of chloro- and bromoarenes via C–H bond activation has been developed. The advantages of this strategy are the employment of cheap Cu(NO3)2·3H2O, LiX and O2, and its compatibility with both electron-donating and electron-withdrawing substituents on aryl rings.