Thiolkatalysierte stereoselektive Transferhydroaminierung von Olefinen mit N‐aminierten Dihydropyridinen

Guin, Joyram; Fröhlich, Roland; Studer, Armido

doi:10.1002/ange.200703902

Cited by 31 publications

(3 citation statements)

References 47 publications

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“…After stirring for 3 h under nitrogen at room temperature, AgCl was removed by filtration through Celite TM under nitrogen and the filtrate was allowed to react for 20 min (10 min ultrasonic bath + 10 min stirring at room temperature) with tosylamine (0.04 g, 0.23 mmol). Evaporation to dryness afforded a grey solid which was recrystallised two times using CH 2 …”

Section: General Procedures (Amine Reactivities)mentioning

confidence: 99%

“…[1] The hydroamination of unactivated alkenes is the shortest synthetic route to secondary and tertiary amines. This atom-economic reaction can be performed on unactivated alkenes according to three methods: radical transfer, [2] , metal catalysis [1,3,4] and acid catalysis. [4,5,6] The last-mentioned method can imply a pure Brøn-stedt acid [5,6] or the combination of a metal and an acid.…”

Section: Introductionmentioning

confidence: 99%

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Inter‐ and Intramolecular Hydroamination of Unactivated Alkenes Catalysed by a Combination of Copper and Silver Salts: The Unveiling of a Brønstedt Acid Catalysis

et al. 2010

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Section: General Procedures (Amine Reactivities)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Inter‐ and Intramolecular Hydroamination of Unactivated Alkenes Catalysed by a Combination of Copper and Silver Salts: The Unveiling of a Brønstedt Acid Catalysis

et al. 2010

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“…[9] Recently the Hantzsch dihydropyridine (not a chiral hydride source) has been used as a transfer-hydrogenation reagent for organocatalytic asymmetric reactions. [10][11][12][13] However, enantio- selective hydrogenation with Hantzsch dihydropyridine has to use costly chiral organocatalysts. To the best of our knowledge, most of the Hantzsch dihydropyridine compounds are neither chiral molecules nor chiral hydride sources, thus, asymmetric reduction with Hantzsch dihydropyridine needs chiral organocatalysts.…”

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confidence: 99%

A Novel NADH Model: Design, Synthesis, and its Chiral Reduction and Fluorescent Emission

Wang¹,

Zhao²

2009

Adv Synth Catal

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A novel chiral nicotinamide adenine dinucleotide hydrogen (NADH) model with C 3 symmetry was designed and synthesized. Hydrogens at the C-4 position of all dihydropyridine rings in the inner part of the bowl could transfer to the substrate with powerful enantioselectivity. This novel C 3 symmetrical NADH model is capable of fluorescence emission at 455 nm when excited at 390 nm.Keywords: chiral NADH model; enantioselectivity; fluorescence; magnesium(II); synthesis The coenzyme nicotinamide adenine dinucleotide hydrogen (NADH) is an important molecule in nature. Over the past several decades, NADH mimics have become one of the highlights of biochemistry and organic chemistry.[1] To the best of our knowledge, the dihydropyridine amido group is the key structure for NADH models.Kanomata [1f] designed and synthesized a bridged NADH model with an [n]A C H T U N G T R E N N U N G (2,5)pyridinophane (parapyridinophane) skeleton as a sterically-demanding side chain that induces high enantioselectivity. Kanomata believed that the oligomethylene chain bridging the 2-and 5-positions of a dihydronicotinoyl ring would behave as an "enzyme wall" that allows the substrates to approach from the opposite side exclusively. In the asymmetric reduction of methyl benzoylformate, mandelate was obtained with a high enantiomeric excess when a 1 molar ratio of magnesium was used.Generally, chemists had formerly designed NADH models according to three aspects: the first one was to control the stereoselectivity by changing the substitutent of the dihydronicotinamide with a view to form a remote sterically-demanding side chain.[2] The second aspect was to incorporate a substituent at the reaction center: the C-4 position of the dihydropyridine ring.[3] The third one was to design the specific conformation to obtain high stereoselectivity.[4] However, in the first situation the dihydronicotinamide unit needs to be modified significantly by introducing big chiral auxiliaries, a complicated ring or by changing the amide group to a chiral sulfinyl group. The second one suffered from loss of chirality at the C-4 position during the course of the model reduction reaction. The third one was particular and by far fewer models have been studied. Herein, a novel chiral NADH model compound 1 with C 3 -symmetry was designed and synthesized.Our model 1 has six chiral carbon centers. (1R,2R)-Diaminocyclohexane is introduced as chiral source to connect three identical pyridine-3,5-dicarbonyl groups into a large ring. Then three identical 1,4-dihydropyridine units are connected by the phenyl-1,3,5-trimethylene group to form model 1. Molecular modeling via molecular dynamics followed by energy minimization with Gaussian 03 shows that the bowl-shaped conformation shown in Figure 1 is the most stable one. The phenyl-1,3,5-trimethylene group is the "bottom" of the "bowl" and the rigidly defined concave cavity of the bowl can hold a metal ion in a fixed position relative to the 1,4-dihydropyridine. As a result, regulation of the stereoselective appro...

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Recent Advances in Electron Donor‐Acceptor (EDA)‐Complex Reactions involving Quaternary Pyridinium Derivatives

Patel

Sharma

2023

Adv Synth Catal

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Quaternary pyridinium compounds are valuable intermediates in organic synthesis, which have gained immense popularity in the synthetic community. The application of transition metal or photoredox catalysis in transforming quaternary pyridinium compounds into various CÀ C and CÀ X bonds is well established. A majority of these methods require high temperatures, expansive catalysts, and delicate conditions for successful execution. On the other hand, the use of transition metal-free and photocatalysis-free strategies in constructing CÀ C and CÀ X bonds using quaternary pyridinium derivatives has been sought-after. In this context, the electron-donor-acceptor (EDA)-complex reactions have emerged as a state-of-the-art organic synthetic methodology, which do not require any photocatalyst for their successful execution. EDA-complex photochemistry takes advantage of the electron-acceptor ability of quaternary pyridinium derivatives, which can quickly generate a radical precursor via the deaminative process. These newly generated radical intermediates are useful in several valuable transformations. We hereby, in this review, discuss an area of major progress in EDA-complex mediated reactions involving quaternary pyridinium compounds with mechanism, substrate scope, and limitations.

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Thiolkatalysierte stereoselektive Transferhydroaminierung von Olefinen mit N‐aminierten Dihydropyridinen

Cited by 31 publications

References 47 publications

Inter‐ and Intramolecular Hydroamination of Unactivated Alkenes Catalysed by a Combination of Copper and Silver Salts: The Unveiling of a Brønstedt Acid Catalysis

Inter‐ and Intramolecular Hydroamination of Unactivated Alkenes Catalysed by a Combination of Copper and Silver Salts: The Unveiling of a Brønstedt Acid Catalysis

A Novel NADH Model: Design, Synthesis, and its Chiral Reduction and Fluorescent Emission

Recent Advances in Electron Donor‐Acceptor (EDA)‐Complex Reactions involving Quaternary Pyridinium Derivatives

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