1359015-27-2Relevant academic research and scientific papers
A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
, p. 6684 - 6690 (2021/05/31)
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
Decarboxylative Elimination of N-Acyl Amino Acids via Photoredox/Cobalt Dual Catalysis
Cartwright, Kaitie C.,Tunge, Jon A.
, p. 11801 - 11806 (2018/12/11)
A dual-catalytic strategy for the synthesis of enamides and enecarbamates directly from easily accessible and inexpensive amino acids has been realized. This mild and efficient protocol makes use of an organic photoredox catalyst and a cobaloxime catalyst to achieve decarboxylative elimination using hydrogen evolution to drive the oxidation. Thus, the reaction occurs without a stoichiometric oxidant or the forcing conditions previously employed in attempts to achieve similar eliminations.
Flavin-Mediated Visible-Light [2+2] Photocycloaddition of Nitrogen- and Sulfur-Containing Dienes
Jirásek, Michael,Straková, Karolína,Nevesely, Tomá?,Svobodová, Eva,Rottnerová, Zdeňka,Cibulka, Radek
, p. 2139 - 2146 (2017/04/24)
The [2+2] photocycloaddition mediated by 1-butyl-3-methyl-7,8-dimethoxyalloxazine (1) has been found to be an effective tool for cyclising ω-phenyl- and ω,ω′-diphenyl-4-aza-1,6-heptadienes, in which the nitrogen atom is protected by acylation or quaternisation, towards the synthesis of a variety of phenyl- and diphenyl-3-azabicyclo[3.2.0]heptanes and their corresponding quaternary salts. Thia derivatives, with the sulfur atom in the form of a sulfone group, underwent an analogous cyclisation. Advantageously, visible light (400 nm) was used for the cycloadditions in the presence of 1, in contrast to the previously described procedures affording azabicyclo[3.2.0]heptanes by using UV irradiation. Practical applications are demonstrated through the synthesis of bicyclic quaternary ammonium salts, 6-phenyl-azabicyclo[3.2.0]heptanes known to exhibit biological activity or chiral spiro ammonium salts. Flavin 1 was also found to promote the efficient E→Z isomerisation of electron-rich cinnamyl derivatives to produce mixtures enriched with the Z isomer (with Z/E ratios of up to 77:23).
Enamides accessed from aminothioesters via a Pd(0)-catalyzed decarbonylative/β-hydride elimination sequence
Min, Geanna K.,Hernandez, Dacil,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information; experimental part, p. 4716 - 4719 (2010/12/25)
A facile synthesis of various enamides from aminothioesters via a palladium(0)-catalyzed decarbonylation/β-hydride elimination is reported. This protocol was applied to mercaptopyridyl C-terminal modified peptides for the generation of enamides without ep
