Synthesis of β-Selenylated Cyclopentanones via Photoredox-Catalyzed Selenylation/Ring-Expansion Cascades of Alkenyl Cyclobutanols

Synlett ◽  
2019 ◽  
Vol 30 (11) ◽  
pp. 1361-1365 ◽  
Author(s):  
Hye Im Jung ◽  
Dae Young Kim
Keyword(s):  
Coupling Reaction ◽  
Ring Expansion ◽  
Cyclic Ketone ◽  
Reaction Conditions ◽  
Blue Led ◽  
Air Atmosphere ◽  
Shelf Stable ◽  
Led Irradiation

A photoredox strategy to access β-selenated cyclic ketone derivatives through the coupling reaction of 1-(1-arylvinyl)cyclobutanols with diselenides under blue LED irradiation and an air atmosphere was developed. This reaction employs the easily accessible and shelf-stable diselenides as a selenium radical source, and the reaction has advantages of mild reaction conditions and broad substrate scope.

Photocatalyzed redox-neutral decarboxylative alkylation of heteroaryl methanamines

2021 ◽  
Vol 23 (2) ◽  
pp. 774-779
Author(s):  
Pengfei Niu ◽  
Jingya Yang ◽  
Yong Yuan ◽  
Yongxin Zhang ◽  
Chenxing Zhou ◽  
...  
Keyword(s):  
Copper Complex ◽  
Coupling Reaction ◽  
Blue Led ◽  
Radical Coupling ◽  
Radical Coupling Reaction ◽  
Led Irradiation

A redox-neutral decarboxylative radical–radical coupling reaction of heteroaryl methylamines with NHPI esters has been developed by employing a copper complex as a photocatalyst with blue LED irradiation.

An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang
Keyword(s):  
Sodium Nitrite ◽  
Oxidative Coupling ◽  
High Resolution Mass Spectrometry ◽  
Coupling Reaction ◽  
13C Nmr Spectroscopy ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Oxidative Coupling Reaction ◽  
Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

Nickel-Catalyzed Multicomponent Coupling Reaction of Alkyl Halides, Isocyanides and H2O: An Expedient Way to Access Alkyl Amides

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3466-3472
Author(s):  
Yunkui Liu ◽  
Bingwei Zhou ◽  
Qiao Li ◽  
Hongwei Jin
Keyword(s):  
Functional Group ◽  
Coupling Reaction ◽  
Alkyl Halides ◽  
Previous Literature ◽  
Catalytic Cycle ◽  
Reaction Conditions ◽  
Multicomponent Coupling ◽  
Easy Operation

We herein describe a Ni-catalyzed multicomponent coupling reaction of alkyl halides, isocyanides, and H2O to access alkyl amides. Bench-stable NiCl2(dppp) is competent to initiate this transformation under mild reaction conditions, thus allowing easy operation and adding practical value. Substrate scope studies revealed a broad functional group tolerance and generality of primary and secondary alkyl halides in this protocol. A plausible catalytic cycle via a SET process is proposed based on preliminary experiments and previous literature.

Room-Temperature, Water-Promoted, Radical-Coupling Reactions of Phenols with tert-Butyl Nitrite

Synlett ◽  
2017 ◽  
Vol 28 (16) ◽  
pp. 2153-2156 ◽  
Author(s):  
Wen-Ting Wei ◽  
Hongze Liang ◽  
Wen-Ming Zhu ◽  
Weida Liang ◽  
Yi Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivative ◽  
Tert Butyl ◽  
Radical Coupling ◽  
Air Atmosphere ◽  
Cross Coupling Reaction ◽  
Temperature Water

A radical–radical cross-coupling reaction of phenols with tert-butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C–N bonds under an air atmosphere at room temperature, providing the ortho-nitrated phenol derivative in moderate to good yields.

scholarly journals The Eschenmoser coupling reaction under continuous-flow conditions

2011 ◽  
Vol 7 ◽  
pp. 1164-1172 ◽  
Author(s):  
Sukhdeep Singh ◽  
J Michael Köhler ◽  
Andreas Schober ◽  
G Alexander Groß
Keyword(s):  
Continuous Flow ◽  
Elevated Temperatures ◽  
Reaction Times ◽  
Coupling Reaction ◽  
Flow Chemistry ◽  
Flow Conditions ◽  
Reaction Conditions ◽  
Bond Forming ◽  
Carbon Carbon Bond ◽  
Reaction Proceeds

The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The reaction kinetics was investigated and 15 examples of different building block combinations are given.

scholarly journals Intermolecular 3+3 Ring Expansion of Aziridines to Dehydropiperidines through the Intermediacy of Aziridinium Ylides

2019 ◽  
Author(s):  
Jennifer Schomaker ◽  
Josephine Eshon ◽  
Kate A. Nicastri ◽  
Steven C. Schmid ◽  
William T. Raskopf ◽  
...  
Keyword(s):  
Natural Product ◽  
Functional Group ◽  
Ring Expansion ◽  
Sigmatropic Rearrangement ◽  
Reactive Intermediate ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Complex Molecules ◽  
Form Complex ◽  
Reaction Proceeds

Bicyclic aziridines undergo formal [3+3] ring expansion reactions when exposed to rhodium-bound vinyl carbenes to form complex dehydropiperidines in a highly stereocontrolled rearrangement. Mechanistic studies and DFT computations indicate the reaction proceeds through the formation of a vinyl aziridinium ylide; this reactive intermediate undergoes a concerted, asynchronous, pseudo-[1,4]- sigmatropic rearrangement to directly furnish the heterocyclic products with net retention at the new C-C bond. In combination with an asymmetric silver-catalyzed aziridination developed in our group, this method quickly delivers enantioenriched scaffolds with up to three contiguous stereocenters. The mild reaction conditions, functional group tolerance, and high stereochemical retention of this method are especially well-suited for appending piperidine motifs to natural product and complex molecules. Ultimately, our work establishes the value of underutilized aziridinium ylides as key intermediates in strategies to convert small, strained rings to larger N-heterocycles.

Ligand free copper(i)-catalyzed synthesis of diaryl ether with Cs2CO3via a free radical path

2015 ◽  
Vol 44 (27) ◽  
pp. 12086-12090 ◽  
Author(s):  
Hong-Jie Chen ◽  
Mei-Chun Tseng ◽  
I-Jui Hsu ◽  
Wei-Ting Chen ◽  
Chien-Chung Han ◽  
...  
Keyword(s):  
Free Radical ◽  
Catalytic Reaction ◽  
Coupling Reaction ◽  
Reaction Conditions ◽  
Esi Ms ◽  
Ms Analysis ◽  
Diaryl Ether ◽  
Ligand Free

Complexes [Cu(i)(2,4-dimethylphenoxy)2]− (A) and [Cu(ii)(2,4-dimethylphenoxy)2(p-tolyl)]− (B) were observed by in situ ESI-MS analysis of the ligand free copper(i)-catalyzed C–O coupling reaction using Cs2CO3 under the catalytic reaction conditions.

scholarly journals Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

2018 ◽  
Vol 14 ◽  
pp. 1871-1884 ◽  
Author(s):  
Siva Sankar Murthy Bandaru ◽  
Darinka Dzubiel ◽  
Heiko Ihmels ◽  
Mohebodin Karbasiyoun ◽  
Mohamed M A Mahmoud ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Binding Constants ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Sonogashira Coupling ◽  
Reaction Conditions ◽  
Quadruplex Dna ◽  
Cross Coupling Reactions ◽  
Sonogashira Coupling Reaction

9-Arylbenzo[b]quinolizinium derivatives were prepared with base-free Suzuki–Miyaura coupling reactions between benzo[b]quinolizinium-9-trifluoroborate and selected benzenediazonium salts. In addition, the Sonogashira coupling reaction between 9-iodobenzo[b]quinolizinium and the arylalkyne derivatives yielded four novel 9-(arylethynyl)benzo[b]quinolizinium derivatives under relatively mild reaction conditions. The 9-(N,N-dimethylaminophenylethynyl)benzo[b]quinolizinium is only very weakly emitting, but the emission intensity increases by a factor >200 upon protonation, so that this derivative may operate as pH-sensitive light-up probe. Photometric and fluorimetric titrations of duplex and quadruplex DNA to 9-(arylethynyl)benzo[b]quinolizinium derivatives revealed a significant binding affinity of these compounds towards both DNA forms with binding constants ofKb= 0.2–2.2 × 105M−1.

Blue LED causes cell death in human hepatoma by inducing DNA damage

2020 ◽  
Author(s):  
Mingyu He ◽  
Guanghui Li ◽  
Xiaoqi He ◽  
Yang Wang ◽  
Hong Lei ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Mechanisms ◽  
Adverse Reactions ◽  
Hepatoma Cell ◽  
Migration And Invasion ◽  
Human Hepatoma ◽  
Curative Effect ◽  
Blue Led ◽  
Sphere Formation ◽  
Led Irradiation

Abstract Phototherapies, including sunlight, infrared, ultraviolet, visible and laser, parts of which present high curative effect, small invasion, and negligible adverse reactions in cancer treatment. Here we aimed to explore the potential therapeutical effects of blue LED in hepatoma cell and decipher the underlying cellular/molecular mechanisms. We demonstrated that the irradiation of blue LED light in hepatoma cell could lead to cell proliferation reduction along with the cell apoptosis increase. Simultaneously, blue LED irradiation also markedly suppressed the migration and invasion ability of hepatoma cells. Sphere formation analysis further revealed the decreased stemness of hepatoma cell under the treatment of blue LED irradiation. In addition, blue LED irradiation significantly promoted the expression of γ-H2AX, a sensitive molecular marker of DNA damage. Collectively, we demonstrated that blue LED irradiation exhibited anti-tumor effects on liver cancer by inducing DNA damage, representing a potential approach for human hepatoma treatment.

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