202934-58-5Relevant academic research and scientific papers
Hydrogenation of Secondary Amides using Phosphane Oxide and Frustrated Lewis Pair Catalysis
K?ring, Laura,Sitte, Nikolai A.,Bursch, Markus,Grimme, Stefan,Paradies, Jan
, p. 14179 - 14183 (2021/09/03)
The metal-free catalytic hydrogenation of secondary carboxylic acid amides is developed. The reduction is realized by two new catalytic reactions. First, the amide is converted into the imidoyl chloride by triphosgene (CO(OCCl3)2) using novel phosphorus(V) catalysts. Second, the in situ generated imidoyl chlorides are hydrogenated in high yields by an FLP-catalyst. Mechanistic and quantum mechanical calculations support an autoinduced catalytic cycle for the hydrogenation with chloride acting as unusual Lewis base for FLP-mediated H2-activation.
Metal-Organic Capsules with NADH Mimics as Switchable Selectivity Regulators for Photocatalytic Transfer Hydrogenation
Wei, Jianwei,Zhao, Liang,He, Cheng,Zheng, Sijia,Reek, Joost N. H.,Duan, Chunying
, p. 12707 - 12716 (2019/09/04)
Switchable selective hydrogenation among the groups in multifunctional compounds is challenging because selective hydrogenation is of great interest in the synthesis of fine chemicals and pharmaceuticals as a result of the importance of key intermediates. Herein, we report a new approach to highly selectively (>99%) reducing C=X (X = O, N) over the thermodynamically more favorable nitro groups locating the substrate in a metal-organic capsule containing NADH active sites. Within the capsule, the NADH active sites reduce the double bonds via a typical 2e- hydride transfer hydrogenation, and the formed excited-state NAD+ mimics oxidize the reductant via two consecutive 1e- processes to regenerate the NADH active sites under illumination. Outside the capsule, nitro groups are highly selectively reduced through a typical 1e- hydrogenation. By combining photoinduced 1e- transfer regeneration outside the cage, both 1e- and 2e- hydrogenation can be switched controllably by varying the concentrations of the substrates and the redox potential of electron donors. This promising alternative approach, which could proceed under mild reaction conditions and use easy-to-handle hydrogen donors with enhanced high selectivity toward different groups, is based on the localization and differentiation of the 2e- and 1e- hydrogenation pathways inside and outside the capsules, provides a deep comprehension of photocatalytic microscopic reaction processes, and will allow the design and optimization of catalysts. We demonstrate the advantage of this method over typical hydrogenation that involves specific activation via well-modified catalytic sites and present results on the high, well-controlled, and switchable selectivity for the hydrogenation of a variety of substituted and bifunctional aldehydes, ketones, and imines.
Mild Metal-Free Hydrosilylation of Secondary Amides to Amines
Huang, Pei-Qiang,Lang, Qi-Wei,Wang, Yan-Rong
, p. 4235 - 4243 (2016/06/09)
The combination of amide activation by Tf2O with B(C6F5)3-catalyzed hydrosilylation with TMDS constitutes a method for the one-pot reduction of secondary amides to amines under mild conditions. The method displays a broad applicability for the reduction of many types of substrates, and shows good compatibility and excellent chemoselectivity for many sensitive functional groups. Reductions of a multifunctionalized α,β-unsaturated amide obtained from another synthetic methodology, and a C-H functionalization product produced the corresponding amines in good to excellent yield. Chemoselective reduction of enantiomeric pure (ee >99%) tetrahydro-5-oxo-2-furaneamides yielded 5-(aminomethyl)dihydrofuran-2(3H)-ones in a racemization-free manner. The latter were converted in one pot to N-protected 5-hydroxypiperidin-2-ones, which are building blocks for the synthesis of many natural products. Further elaboration of an intermediate led to a concise four-step synthesis of -epi-pseudoconhydrine.
Transformation of N,N-diisopropylarylmethylamines into N-isopropylarylmethylamines with molecular iodine
Ezawa, Masatoshi,Moriyama, Katsuhiko,Togo, Hideo
, p. 6689 - 6692 (2016/02/03)
N,N-Diisopropylarylmethylamines were smoothly converted into the corresponding N-isopropylarylmethylamines by the reaction with molecular iodine in the presence of Na2CO3 in chloroform at 60 °C. Other related tertiary amines were also transformed into the corresponding secondary amines by the reaction with molecular iodine under the same reaction conditions.
Substituted indolines which inhibit receptor tyrosine kinases
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Page column 42, (2008/06/13)
Indolinones of the formula having an inhibitory effect on receptor tyrosine kinases and cyclin/CDK complexes, as well as on the proliferation of endothelial cells and various tumor cells. Exemplary are: (a) 3-Z-[1-(4-(piperidin-1-yl-methyl)-anilino)-1-phenyl-methylene]-6-ethoxycarbonyl-2-indolinone, (b) 3-Z-[(1-(4-(piperidin-1-yl-methyl)-anilino)-1-phenyl-methylene]-6-carbamoyl-2-indolinone, and (c) 3-Z-[1-(4-(piperidin-1-yl-methyl)-anilino)-1-phenyl-methylene]-6-metboxycarbonyl-2-indolinone.
Substituted indolinones with kinase inhibitory activity
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, (2008/06/13)
Substituted indolinones of general formula having effect on various kinases and cycline/CDK complexes and on the proliferation of various tumour cells. Exemplary compounds are: 3-Z-[1-(4-(N-Benzyl-N-methyl-aminomethyl)-phenylamino)-1-methyl-methylene]-5-a
Indolinones having kinase inhibitory activity
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, (2008/06/13)
The present invention relates to substituted indolinones of general formula [Figure] wherein R1 to R5, and X are defined as in claim 1, the isomers thereof and the salts thereof, particularly the physiologically acceptable salts thereof which have valuable pharmacological properties, particularly an inhibitory effect on various kinases and cycline/CDK complexes and on the proliferation of various tumour cells, pharmaceutical compositions containing these (compounds, their use and processes for preparing them.
Reactions of N-Chlorobenzylalkylamines with Sodium Methoxide in Methanol. Steric Effects in Elimination Reactions
Cho, Bong Rae,Maeng, Jun Ho,Yoon, Jong Chan,Kim, Tae Rin
, p. 4752 - 4756 (2007/10/02)
Reactions of N-chlorobenzylalkylamines in which the alkyl group is Me, Et, i-Pr, t-Bu, and sec-Bu with MeONa-MeOH have been investigated kinetically.The eliminations are quantitative and regiospecific, producing only benzylidenealkylamines.The reactions are first order in base and first order in substrate, and an E2 mechanism is evident.The relative rates of elimination at 25 deg C are 1/0.5/0.3/0.2/0.01 for Me/Et/i-Pr/sec-Bu/t-Bu alkyl substituents, respectively.The results are attributed to repulsive interaction between the alkyl group and the base in the transition state.Hammett ρ and kH/kD values decreased, but the ΔH(excit.) and ΔS(excit.) values increased with bulkier alkyl substituents.Changes in the transition-state parameters with the substrate steric effect are interpreted with variation in structure of the imine-forming transition states.
