.beta. Scission of acyl radicals in the radical decomposition of various .alpha.-hydroperoxy ketones

1976 ◽  
Vol 41 (13) ◽  
pp. 2340-2343 ◽  
Author(s):  
Yasuhiko. Sawaki ◽  
Yoshiro. Ogata
Keyword(s):  
Acyl Radicals ◽  
Radical Decomposition

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

scholarly journals Selective 6-endo Cyclization of the Acyl Radicals onto the Nitrogen of Imine and Oxazoline C—N Bonds.

ChemInform ◽  
2006 ◽  
Vol 37 (44) ◽  
Author(s):  
Mami Tojino ◽  
Noboru Otsuka ◽  
Takahide Fukuyama ◽  
Hiroshi Matsubara ◽  
Ilhyong Ryu
Keyword(s):  
Acyl Radicals

On the rates of decarbonylation of hydroxyacetyl and other acyl radicals

1986 ◽  
Vol 18 (7) ◽  
pp. 791-800 ◽  
Author(s):  
J. -K. Vollenweider ◽  
H. Paul
Keyword(s):  
Acyl Radicals

The Role of the Solvent in Radical Decomposition Reactions: p-Nitrophenylazotris-(p-anisyl)-methane

1954 ◽  
Vol 76 (16) ◽  
pp. 4169-4171 ◽  
Author(s):  
Mendel D. Cohen ◽  
John E. Leffler ◽  
Libero M. Barbato
Keyword(s):  
Decomposition Reactions ◽  
Radical Decomposition

scholarly journals Wireless Sensor Network for Sustainable Agriculture

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1302 ◽  
Author(s):  
Carlos D. Moreno-Moreno ◽  
María Brox-Jiménez ◽  
Andrés A. Gersnoviez-Milla ◽  
Mariano Márquez-Moyano ◽  
Manuel A. Ortiz-López ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Atmospheric Pressure ◽  
Rainfall Intensity ◽  
Phytophthora Cinnamomi ◽  
Luminous Flux ◽  
Climatic Conditions ◽  
Wireless Sensor ◽  
Evolution And Development ◽  
Oak Trees ◽  
Radical Decomposition

Precision agriculture can be defined as the science of using technology to improve the agricultural production. It is advisable for farmers to use a decision support system; in fact, real–time monitoring of climatic conditions is the only way to know the water needed by a cultivation. On the other hand, since the 1990s, a strong decrease of the Mediterranean Quercus has been observed in the pastures of southwestern Spain and Portugal, causing a high mortality of holm and cork oak trees. Among the factors associated with this decrease, the radical decomposition caused by Phytophthora Cinnamomi is remarkable for its gravity, which makes it necessary to reforest the trees and to monitor the microclimatic factors that have an influence on this regeneration. Wireless Sensor Networks (WSN) are a technology in full evolution and development, as well as their appropriate use in cultivations that help to implement ecological techniques. With these considerations in this work five units/nodes with one or more sensors that allow different environmental readings have been developed. In this work, the acquisition of data obtained from different sensors has been achieved, allowing the monitoring of climatic elements such as soil moisture, air quality, temperature and humidity, rainfall intensity, precipitation level, wind speed and direction, luminous flux and atmospheric pressure. A web page has been designed where the user can consult the climatic conditions of the cultivation or reforestation. Different devices interconnected with a central unit have been developed where measurements of the cultivation are sent for its later analysis by the farmer. The microclimatic data acquisition developed in the WSN proposed in this paper allows a farmer to make decisions about the irrigation of the cultivation, use of fertilizers, the development and maturation phases of the cultivated products, obtaining the optimum stages of cultivation and harvesting.

scholarly journals Light-Driven Vitamin B12 -Catalysed Generation of Acyl Radicals from 2-S -Pyridyl Thioesters

2017 ◽  
Vol 359 (20) ◽  
pp. 3560-3565 ◽  
Author(s):  
Michał Ociepa ◽  
Oskar Baka ◽  
Jakub Narodowiec ◽  
Dorota Gryko
Keyword(s):  
Vitamin B12 ◽  
Acyl Radicals

scholarly journals DABCO-promoted photocatalytic C–H functionalization of aldehydes

2021 ◽  
Vol 17 ◽  
pp. 2959-2967
Author(s):  
Bruno Maia da Silva Santos ◽  
Mariana dos Santos Dupim ◽  
Cauê Paula de Souza ◽  
Thiago Messias Cardozo ◽  
Fernanda Gadini Finelli
Keyword(s):  
Hydrogen Atom ◽  
Cross Coupling ◽  
Hydrogen Atom Transfer ◽  
Direct Application ◽  
Atom Transfer ◽  
Organic Base ◽  
Aryl Bromides ◽  
Computational Calculations ◽  
Acyl Radicals ◽  
Aryl Ketones

Herein we present a direct application of DABCO, an inexpensive and broadly accessible organic base, as a hydrogen atom transfer (HAT) abstractor in a photocatalytic strategy for aldehyde C–H activation. The acyl radicals generated in this step were arylated with aryl bromides through a well stablished nickel cross-coupling methodology, leading to a variety of interesting aryl ketones in good yields. We also performed computational calculations to shine light in the HAT step energetics and determined an optimized geometry for the transition state, showing that the hydrogen atom transfer between aldehydes and DABCO is a mildly endergonic, yet sufficiently fast step. The same calculations were performed with quinuclidine, for comparison of both catalysts and the differences are discussed.

Sign in / Sign up

Export Citation Format

Share Document