205242-33-7Relevant academic research and scientific papers
Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols
Feng, Xinshu,Huang, Ming
, (2021/06/21)
A series of air-stable N-heterocyclic carbene (NHC) Ir(III) complexes (Ir1-6), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N-alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1,3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into mono-N-alkylated amines in 53–96% yields. As a special highlight, for the challenging MeOH, selective N-monomethylation could be achieved using KOH as a base under an air atmosphere. Moreover, this catalytic system was successfully applied to the gram-scale synthesis of some valuable compounds.
Tungsten-Catalyzed Direct N-Alkylation of Anilines with Alcohols
Lan, Xiao-Bing,Ye, Zongren,Yang, Chenhui,Li, Weikang,Liu, Jiahao,Huang, Ming,Liu, Yan,Ke, Zhuofeng
, p. 860 - 865 (2021/01/18)
The implementation of non-noble metals mediated chemistry is a major goal in homogeneous catalysis. Borrowing hydrogen/hydrogen autotransfer (BH/HA) reaction, as a straightforward and sustainable synthetic method, has attracted considerable attention in the development of non-noble metal catalysts. Herein, we report a tungsten-catalyzed N-alkylation reaction of anilines with primary alcohols via BH/HA. This phosphine-free W(phen)(CO)4 (phen=1,10-phenthroline) system was demonstrated as a practical and easily accessible in-situ catalysis for a broad range of amines and alcohols (up to 49 examples, including 16 previously undisclosed products). Notably, this tungsten system can tolerate numerous functional groups, especially the challenging substrates with sterically hindered substituents, or heteroatoms. Mechanistic insights based on experimental and computational studies are also provided.
N-Alkylation of Amines with Alcohols Catalyzed by Manganese(II) Chloride or Bromopentacarbonylmanganese(I)
Wei, Dongyue,Yang, Peng,Yu, Chuanman,Zhao, Fengkai,Wang, Yilei,Peng, Zhihua
, p. 2254 - 2263 (2021/02/26)
A manganese-catalyzed N-alkylation reaction of amines with alcohols via hydrogen autotransfer strategy has been demonstrated. The developed practical catalytic system including an inexpensive, nontoxic, commercially available MnCl2 or MnBr(CO)5 as the metal salt and triphenylphosphine as a ligand provides access to diverse aromatic, heteroaromatic, and aliphatic secondary amines in moderate-to-high yields. In addition, this operationally simple protocol is scalable to the gram level and suitable for synthesizing heterocycles such as indole and resveratrol-derived amines known to be active for Alzheimer's disease.
Base-mediated cascade amidination/: N -alkylation of amines by alcohols
Hu, Mao-Lin,Jia, Xiaofei,Liang, Zuyu,Lu, Fenghong,Zhang, Chunyan,Zhang, Guoying
supporting information, p. 10489 - 10492 (2020/10/02)
A base-mediated cascade amidination/N-alkylation reaction of amines by alcohols has been developed. For the first time, nitriles have been identified as an efficient and benign water acceptor reagent in N-alkylation. Notably, the procedure tolerates a series of functional groups, such as methoxyl, halo, vinyl and hetero groups, providing a convenient method to construct different substituted diamino compounds, 15N labeled amine and could be scaled up to 1 mol scale offering 138.7 g of the desired product in good yield in one-pot. Mechanistic studies provided strong evidence for the amidination of amines with nitriles facilitated by t-BuOK.
A bifunctional strategy for N-heterocyclic carbene-stabilized iridium complex-catalyzed: N -alkylation of amines with alcohols in aqueous media
Huang, Ming,Li, Yinwu,Liu, Jiahao,Lan, Xiao-Bing,Liu, Yan,Zhao, Cunyuan,Ke, Zhuofeng
supporting information, p. 219 - 224 (2019/01/28)
Through the strategy of combining bifunctional 2-hydroxypyridine and a thermally stable N-heterocyclic carbene ligand, an Ir-catalyzed N-monoalkylation reaction has been developed in aqueous media under base-free conditions. This reaction proceeds smoothly with high yields of various aromatic amines and sulfonamides with a wide range of primary alcohols. Experimental and computational studies revealed a metal-ligand cooperative mechanism and its thermal stability during the bifunctional catalysis in aqueous media.
Manganese-Catalyzed and Base-Switchable Synthesis of Amines or Imines via Borrowing Hydrogen or Dehydrogenative Condensation
Fertig, Robin,Irrgang, Torsten,Freitag, Frederik,Zander, Judith,Kempe, Rhett
, p. 8525 - 8530 (2018/09/06)
The use of earth-abundant transition metals as a noble metal replacement in catalysis is especially interesting if different catalytic reactivity is observed. We report, here, on the selective manganese-catalyzed base-switchable synthesis of N-alkylated amines or imines. In both reactions, borrowing hydrogen/hydrogen autotransfer (N-alkyl amine formation) or dehydrogenative condensation (imine formation), we start from the same amines and alcohols and use the same Mn precatalyst. The key is the presence of a potassium base to prefer N-alkylation and a sodium base to permit imine formation. Both bases react with the manganese hydride via deprotonation. The potassium manganate hydride reacts about 40 times faster with an imine to give the corresponding amine than the sodium manganate hydride. The selectivity seems unique for manganese complexes. We observe a broad scope with a complete product overlap, all amine alcohol combinations can be converted into an N-alkyl amine or an imine, and a good functional group tolerance.
Cu-Catalyzed Intramolecular Amidation of Unactivated C(sp3)-H Bonds to Synthesize N-Substituted Indolines
Pan, Fei,Wu, Bin,Shi, Zhang-Jie
supporting information, p. 6487 - 6490 (2016/05/02)
A copper-catalyzed intramolecular amidation of unactivated C(sp3)-H bonds to construct indoline derivatives has been developed. Such an amidation proceeded well at primary C-H bonds preferred to secondary C-H bonds. The transformation owned a b
Photoreactions with a Twist: Atropisomerism-Driven Divergent Reactivity of Enones with UV and Visible Light
Vallavoju, Nandini,Sreenithya, Avadakkam,Ayitou, Anoklase J.-L.,Jockusch, Steffen,Sunoj, Raghavan B.,Sivaguru, Jayaraman
supporting information, p. 11339 - 11348 (2016/08/03)
Light-induced transformation of atropisomeric and achiral enones displays divergent reactivity. Photocyclization leading to 3,4-dihydroquinolin-2-one was observed with achiral enone carboxamide, whereas the atropisomeric enone carboxamides underwent hydro
New Iridium Catalysts for the Selective Alkylation of Amines by Alcohols under Mild Conditions and for the Synthesis of Quinolines by Acceptor-less Dehydrogenative Condensation
Ruch, Susanne,Irrgang, Torsten,Kempe, Rhett
supporting information, p. 13279 - 13285 (2016/02/19)
A novel family of iridium catalysts stabilised by P,N-ligands have been introduced. The ligands are based on imidazo[1,5-b]pyridazin-7-amines and can be synthesised with a broad variety of substitution patterns. The catalysts were synthesised quantitatively from the protonated ligands and a commercially available iridium precursor. The catalysts mediate the alkylation of amines by alcohols under mild conditions (70 °C). In addition, the synthesis of quinolines from secondary or primary alcohols and amino alcohols is reported. This sustainable synthesis proceeds through the liberation of two equivalents of water and two equivalents of dihydrogen. The investigations indicate that catalysts suitable for hydrogen autotransfer or borrowing hydrogen chemistry might also be suitable for acceptor-less dehydrogenative condensation reactions. Your H or mine? A family of catalysts that mediate the alkylation of amines by alcohols under mild conditions are introduced (see scheme; HA=hydrogen autotransfer, BH=borrowing hydrogen, ADC=acceptor-less dehydrogenative condensation). The efficient synthesis of quinolines from alcohols and amino alcohols through the liberation of two equivalents of dihydrogen is also mediated by this catalyst family.
