- Ru-NHC-Catalyzed Asymmetric Hydrogenation of 2-Quinolones to Chiral 3,4-Dihydro-2-Quinolones
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Direct enantioselective hydrogenation of unsaturated compounds to generate chiral three-dimensional motifs is one of the most straightforward and important approaches in synthetic chemistry. We realized the Ru(II)-NHC-catalyzed asymmetric hydrogenation of 2-quinolones under mild reaction conditions. Alkyl-, aryl- and halogen-substituted optically active dihydro-2-quinolones were obtained in high yields with moderate to excellent enantioselectivities. The reaction provides an efficient and atom-economic pathway to construct simple chiral 3,4-dihydro-2-quinolones. The desired products could be further reduced to tetrahydroquinolines and octahydroquinolones.
- Daniliuc, Constantin,Glorius, Frank,Hu, Tianjiao,Lückemeier, Lukas
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supporting information
p. 23193 - 23196
(2021/09/25)
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- Lactamization of alkenyl C-H bonds to generate 2-quinolinones with triphosgene
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A simple and easy-going method is developed to synthesize the analogues of 2-quinolinones by using triphosgene (BTC) as the carbonyl source. In these reactions, both the toxic carbon monoxide (CO) and phosgene are avoided and the 2-quinolinones are obtained in moderate to good yields under mild conditions, all of which are anticipated to be meaningful in both industry and laboratory.
- Du, Guizhi,Wang, Zixiao,Zhang, Zhen
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p. 600 - 608
(2020/06/03)
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- Synthesis and antileishmanial evaluation of thiazole orange analogs
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Cyanine compounds have previously shown excellent in vitro and promising in vivo antileishmanial efficacy, but the potential toxicity of these agents is a concern. A series of 22 analogs of thiazole orange ((Z)-1-methyl-4-((3-methylbenzo[d]thiazol-2(3H)-ylidene)methyl)quinolin-1-ium salt), a commercial cyanine dye with antileishmanial activity, were synthesized in an effort to increase the selectivity of such compounds while maintaining efficacy. Cyanines possessing substitutions on the quinolinium ring system displayed potency against Leishmania donovani axenic amastigotes that differed little from the parent compound (IC50 12–42 nM), while ring disjunction analogs were both less potent and less toxic. Changes in DNA melting temperature were modest when synthetic oligonucleotides were incubated with selected analogs (ΔTm ≤ 5 °C), with ring disjunction analogs showing the least effect on this parameter. Despite the high antileishmanial potency of the target compounds, their toxicity and relatively flat SAR suggests that further information regarding the target(s) of these molecules is needed to aid their development as antileishmanials.
- Abdelhameed, Ahmed,Liao, Xiaoping,McElroy, Craig A.,Joice, April C.,Rakotondraibe, Liva,Li, Junan,Slebodnick, Carla,Guo, Pu,Wilson, W. David,Werbovetz, Karl A.
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supporting information
(2019/11/28)
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- Synthesis of 2-Quinolinones via a Hypervalent Iodine(III)-Mediated Intramolecular Decarboxylative Heck-Type Reaction at Room Temperature
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A hypervalent iodine(III)-mediated intramolecular decarboxylative Heck-type reaction of 2-vinyl-phenyl oxamic acids has been developed. The unique ring-strain-enabled radical decarboxylation mechanism is preliminarily revealed. This protocol features metal-free reaction conditions and operational simplicity, allowing the lactamization of 2-vinylanilines using a readily accessible carbonyl source and the synthesis of various 2-quinolinones with excellent chemoselectivity at room temperature.
- Fan, Huaqiang,Pan, Peng,Zhang, Yongqiang,Wang, Wei
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p. 7929 - 7932
(2019/01/04)
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- Lactamization of sp2C?H Bonds with CO2: Transition-Metal-Free and Redox-Neutral
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The first direct use of carbon dioxide in the lactamization of alkenyl and heteroaryl C?H bonds to synthesize important 2-quinolinones and polyheterocycles in moderate to excellent yields is reported. Carbon dioxide, a nontoxic, inexpensive, and readily available greenhouse gas, acts as an ideal carbonyl source. Importantly, this transition-metal-free and redox-neutral process is eco-friendly and desirable for the pharmaceutical industry. Moreover, these reactions feature a broad substrate scope, good functional group tolerance, facile scalability, and easy product derivatization.
- Zhang, Zhen,Liao, Li-Li,Yan, Si-Shun,Wang, Lei,He, Yun-Qi,Ye, Jian-Heng,Li, Jing,Zhi, Yong-Gang,Yu, Da-Gang
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supporting information
p. 7068 - 7072
(2016/07/06)
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- Diastereoselective hydrogenation of substituted quinolines to enantiomerically pure decahydroquinolines
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The stereoselective hydrogenation of auxiliary-substituted quinolines was used to build up saturated and partially saturated heterocycles. In a first step, the formation and diastereoselective hydrogenation of 2-oxazolidinone- substituted quinolines to 5,6,7,8-tetrahydroquinolines is reported. In this unprecedented process, stereocenters on the carbocyclic quinoline ring were formed with a dr of up to 89:11. Platinum oxide as a catalyst and trifluoroacetic acid as a solvent were found to be optimal for high levels of chemo- and stereoselectivity in this step. In a second hydrogenation step, the completely saturated decahydroquinolines with 4 newly formed stereocenters were obtained with enantioselectivities of up to 99%. Rhodium on carbon as a catalyst and acetic acid as a solvent gave the best results for this hydrogenation and allowed a traceless cleavage of the chiral auxiliary. Thus, this new method allows an efficient stereoselective synthesis of valuable 5,6,7,8-tetrahydro- and decahydroquinoline products.
- Heitbaum, Maja,Froehlich, Roland,Glorius, Frank
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supporting information; experimental part
p. 357 - 362
(2010/05/19)
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- Synthesis of 7-Methyl-1,2-dihydroquinolin-2-ones as Angiotensin II Receptor Antagonists
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A number of biphenyl substituted 1,2-dihydroquinolin-2-ones were synthesized by regiospecific alkylation of the corresponding 1H-derivatives.Again, these precursors were prepared in three steps by acetoacetylation of anilines, regiospecific C-alkylation of the resulting β-ketoanilides and subsequent condensation to the quinolines.One of the target compounds, 2--1,2-dihydroquinolin-3-yl>-N,N-dimethylacetamide (10e), is a potent angiotensin II receptor antagonist.
- Beier, Norbert,Labitzke, Erwin,Mederski, Werner W.K.R.,Radunz, Hans-Eckart,Rauschenbach-Ruess, Karin,Schneider, Bjoern
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p. 117 - 132
(2007/10/02)
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