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
Cobalt complexes of redox noninnocent azo-aromatic pincers. Isolation, characterization, and application as catalysts for the synthesis of quinazolin-4(3<i>H</i>)-ones
作者:Suman Sinha、Siuli Das、Rakesh Mondal、Sutanuva Mandal、Nanda D. Paul
DOI:10.1039/d0dt00394h
日期:——
9-bis(phenyldiazo)-1,10-phenanthroline (L2) ligands produced two new mononuclear five-coordinate cobalt(II)-complexes 1b and 2 respectively. In complex 1a and 1b, the ligands L1a and L1b are coordinated to the cobalt(II)-center in a tridentate mode utilizing all of its nitrogen donor sites while in complex 2 one of the azo-donor sites of the ligand L2 remain pendant. All these complexes were characterized using available
“Inverse” Frustrated Lewis Pairs: An Inverse FLP Approach to the Catalytic Metal Free Hydrogenation of Ketones
作者:Suresh Mummadi、Amandeep Brar、Guoqiang Wang、Dustin Kenefake、Rony Diaz、Daniel K. Unruh、Shuhua Li、Clemens Krempner
DOI:10.1002/chem.201804370
日期:2018.11.7
For the first time have boron‐containing weak Lewis acids been demonstrated to be active components of Frustrated LewisPair (FLP) catalysts in the hydrogenation of ketones to alcohols. Combining the organosuperbase (pyrr)3P=NtBu with the Lewis acid 9‐(4‐CF3‐C6H4)‐BBN generated an “inverse” FLP catalyst capable of hydrogenating a range of aliphatic and aromatic ketones including N‐, O‐ and S‐functionalized
含硼的弱路易斯酸首次被证明是酮加氢成醇时的沮丧路易斯对(FLP)催化剂的活性组分。将有机超强碱(pyrr)3 P = N t Bu与路易斯酸9-(4-CF 3 - C 6 H 4)-BBN结合产生一种“逆向” FLP催化剂,该催化剂能够加氢包括N在内的一系列脂族和芳族酮,O和S功能化的底物以及生物质衍生的乙酰丙酸乙酯。初步的计算和实验研究表明,使用“逆” FLP进行催化氢化的机理不同于包含强路易斯酸(例如B(C 6 F 5))的常规FLP催化剂。)3。
Fe-Catalyzed Acceptorless Dehydrogenation of Secondary Benzylic Alcohols
作者:Hansoo Song、Byungjoon Kang、Soon Hyeok Hong
DOI:10.1021/cs5007316
日期:2014.9.5
Oxidation of alcohols is an essential organic reaction, affording versatile carbonyl groups. To provide a sustainable solution for environmentally harmful traditional oxidation methods, the transition-metal catalyzed acceptor-free dehydrogenation of alcohols has attracted much attention. The widely used catalysts for the dehydrogenation reaction are based on precious metals, which are not economical
醇的氧化是必不可少的有机反应,可提供多种羰基。为了提供对环境有害的传统氧化方法的可持续解决方案,醇的过渡金属催化的无受体脱氢倍受关注。用于脱氢反应的广泛使用的催化剂基于贵金属,这不经济且对环境无害。我们开发了一种操作简单,经济,环境友好的无Fe催化的各种仲苄醇脱氢反应,以提供相应的酮和H 2。一种现成的乙酰丙酮铁(III),1,10-菲咯啉和K 2 CO 3的简单原位混合物 被确定为该转化的活性催化剂。
Efficient transfer hydrogenation of ketones in the presence of ruthenium N-heterocyclic carbene catalysts
Novel ruthenium carbene complexes have been in situ generated and tested for the transfer hydrogenation of ketones. Applying Ru(cod)(methylallyl)2 in the presence of imidazolium salts in 2-propanol and sodium-2-propanolate as base, turnover frequencies up to 346 h−1 have been obtained for reduction of acetophenone. A comparative study involving ruthenium carbene and ruthenium phosphine complexes demonstrated
新型钌卡宾配合物已就地生成,并进行了酮转移氢化的测试。在咪唑盐在2-丙醇和-2-丙醇钠中作为碱存在下,应用Ru(cod)(甲基烯丙基)2,可以得到高达346 h -1的周转频率以还原苯乙酮。一项涉及钌卡宾和钌膦配合物的比较研究表明,钌卡宾配合物具有更高的活性。