scholarly journals Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes

2019 ◽  
Author(s):  
Jamie Leitch ◽  
Tatiana Rogova ◽  
Fernanda Duarte ◽  
Darren J. Dixon
Keyword(s):  
Reaction Mechanism ◽  
Radical Addition ◽  
Ring Closure ◽  
Natural Product Synthesis ◽  
Quinoline Derivatives ◽  
Wide Scope ◽  
Mechanistic Studies ◽  
Good Efficiency ◽  
Quaternary Centers

The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provide insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.<br>

scholarly journals Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes

2019 ◽  
Author(s):  
Jamie Leitch ◽  
Tatiana Rogova ◽  
Fernanda Duarte ◽  
Darren J. Dixon
Keyword(s):  
Reaction Mechanism ◽  
Radical Addition ◽  
Ring Closure ◽  
Natural Product Synthesis ◽  
Quinoline Derivatives ◽  
Wide Scope ◽  
Mechanistic Studies ◽  
Good Efficiency ◽  
Quaternary Centers

The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provide insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.<br>

scholarly journals The Synthesis of Conjugated Bis-Aryl Vinyl Substrates and Their Photoelectrocyclization Reactions towards Phenanthrene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Jon D. Rainier ◽  
Xuchen Zhao
Keyword(s):  
Natural Product ◽  
Natural Product Synthesis ◽  
Mechanistic Studies ◽  
Efficient Strategy

AbstractThe photoelectrocyclization of conjugated vinyl biaryls has proven to be a valuable and efficient strategy for generating phenanthrene derivatives. Contained in this review is an overview of the mechanism for the transformation and a discussion of the reaction scope with a focus on the electrocyclization itself, rearomatization, and the application of the reaction in natural product synthesis.1 Introduction2 The Synthesis of Conjugated Vinyl Biaryls3 Mechanistic Studies4 Substrate Scope5 Applications6 Conclusions

scholarly journals PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation

2021 ◽  
pp. 174751982098753
Author(s):  
Xiaofang Wu ◽  
Lei Zhou ◽  
Fangshao Li ◽  
Jing Xiao
Keyword(s):  
Acid Chloride ◽  
Bioactive Molecules ◽  
Mechanistic Studies ◽  
One Pot ◽  
Tert Butyl ◽  
Butyl Esters

A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.

scholarly journals In situ XRD and operando spectra-electrochemical investigation of tetragonal WO3-x nanowire networks for electrochromic supercapacitors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Shen Wang ◽  
Hongbo Xu ◽  
Tingting Hao ◽  
Peiyuan Wang ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Electronic Device ◽  
High Capacity ◽  
Optical Modulation ◽  
Function Evaluation ◽  
Dual Function ◽  
Electrochemical Performances ◽  
Electrochemical Cycling ◽  
Nanowire Networks

AbstractElectrochromic supercapacitors (ESCs) are appealing for smart electronic device applications due to their advantages of dual-function integration. Unfortunately, the synchronous dual-function evaluation and the essential reaction mechanism are ambiguous. Herein, we constructed a 3D WO3-x nanowire networks/fluorine-doped tin oxide (WO3-x NWNs/FTO) bifunctional electrode for ESCs by a solvothermal self-crystal seeding method. The synchronous correspondence relationship between the optical and electrochemical performances of the WO3-x NWNs/FTO electrode was explored using an operando spectra-electrochemical characterization method. It reveals an excellent areal capacity of 57.57 mF cm−2 with a high corresponding optical modulation (ΔT) of 85.05% and high optical-electrochemical cycling stability. Furthermore, the synergistic reaction mechanism between the Al3+ ion intercalation behavior and the surface pseudocapacitance reaction during electrochemical cycling is revealed utilizing in situ X-ray diffraction. Based on these results, an ESC device was constructed by pairing WO3-x/FTO as the cathode with V2O5 nanoflowers/FTO (V2O5 NFs/FTO) as the anode, which simultaneously deliver high capacity and large optical modulation. Moreover, the energy storage level of the ESC device could be visually monitored by rapid and reversible color transitions in real time. This work provides a promising pathway to developing multi-functional integrated smart supercapacitors.

In-situ study of the diffusion-reaction mechanism in Mo/Si multilayered films

2011 ◽  
Vol 257 (7) ◽  
pp. 2707-2711 ◽  
Author(s):  
S. Bruijn ◽  
R.W.E. van de Kruijs ◽  
A.E. Yakshin ◽  
F. Bijkerk
Keyword(s):  
Reaction Mechanism ◽  
Diffusion Reaction ◽  
Multilayered Films ◽  
In Situ Study

scholarly journals Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

2016 ◽  
Vol 12 ◽  
pp. 1421-1427 ◽  
Author(s):  
Grzegorz Mlostoń ◽  
Róża Hamera-Fałdyga ◽  
Anthony Linden ◽  
Heinz Heimgartner
Keyword(s):  
Reaction Mechanism

Ferrocenyl hetaryl thioketones react smoothly with in situ generated thiocarbonyl S-methanides to give 1,3-dithiolanes. In the case of aromatic S-methanides, the sterically more crowded 4,4,5,5-tetrasubstituted 1,3-dithiolanes (2-CH2 isomers) were formed as sole products. The reactions with cycloaliphatic S-methanides led to mixtures of 2-CH2 and 5-CH2 isomers with the major component being the sterically more crowded 2-CH2 isomers. The preferred formation of the latter products is explained by the assumption that the formal [3 + 2]-cycloadducts were formed via a stepwise reaction mechanism with a stabilized 1,5-diradical as a key intermediate. The complete change of the reaction mechanism toward the concerted [3 + 2]-cycloaddition was observed in the reaction of a sterically crowded cycloaliphatic thiocarbonyl ylide with ferrocenyl methyl thioketone.

scholarly journals Mechanistic studies on lithium intercalation in a lithium-rich layered material using Li2RuO3epitaxial film electrodes and in situ surface X-ray analysis

2014 ◽  
Vol 2 (42) ◽  
pp. 17875-17882 ◽  
Author(s):  
Sou Taminato ◽  
Masaaki Hirayama ◽  
Kota Suzuki ◽  
KyungSu Kim ◽  
Yueming Zheng ◽  
...  
Keyword(s):  
Layered Material ◽  
Lithium Intercalation ◽  
Mechanistic Studies ◽  
X Ray
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