Novel regio- and stereoselective phosphonyl radical addition to glycals promoted by Mn(ii)–air: syntheses of 1,2-dideoxy 2-C-diphenylphosphinylglycopyranosides

2014 ◽  
Vol 50 (16) ◽  
pp. 2046-2048 ◽  
Author(s):  
Fuyi Zhang ◽  
Liming Wang ◽  
Cui Zhang ◽  
Yufen Zhao
Keyword(s):  
Radical Reaction ◽  
Radical Addition ◽  
The Novel ◽  
Diphenylphosphine Oxide ◽  
Phosphonyl Radical

The novel Mn(ii)–air promoted radical reaction of diphenylphosphine oxide with various glycals in excellent regio- and stereoselectivities generated 1,2-dideoxy-2-C-diphenylphosphinylglycopyranosides.

scholarly journals Semiconductors as sensitisers for the radical addition of tertiary amines to electron deficient alkenes

2003 ◽  
Vol 5 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Siniša Marinković ◽  
Norbert Hoffmann
Keyword(s):  
Electron Transfer ◽  
Organic Synthesis ◽  
Radical Reaction ◽  
Heterogeneous Photocatalysis ◽  
Radical Addition ◽  
Point Of View ◽  
Tertiary Amines ◽  
Radical Intermediate ◽  
Radical Chain ◽  
High Yields

Using heterogeneous photocatalysis, the radical addition of tertiary amines with electron deficient alkenes can be performed in high yields (up to 98%) and high facial diastereoselectivity. The photochemical induced electron transfer process initiates the radical chain reaction and inorganic semiconductors likeTiO2and ZnS were used. According to the proposed mechanism, the reaction takes place at the surface of the semiconductor and the termination step results from an interfacial electron transfer from the conduction band to the oxoallyl radical intermediate. Frequently, semiconductors are used for the mineralisation of organic compounds in wastewater. However, in this case, they are used in organic synthesis. The process can be performed in a convenient way and is particularly interesting from the ecological and economical point of view. No previous functionalization of the tertiary amines is necessary for C − C bond formation. Further on, the amines are used both as reactant and as solvent. The excess is recycled by distillation and the inexpensive sensitiser can be easily removed by filtration. In this way, products of high interest for organic synthesis are obtained by a diastereoselective radical reaction.

Preparation of some new anomeric carbohydrate difluoromethylenephosphonates via phosphonyl radical addition to gem-difluoroenol ethers

1996 ◽  
pp. 613 ◽  
Author(s):  
Timoth�e F. Herpin ◽  
J. Sarah Houlton ◽  
William B. Motherwell ◽  
Brian P. Roberts ◽  
Jean-Marc Weibel
Keyword(s):  
Radical Addition ◽  
Phosphonyl Radical

Phosphonyl Radical Addition to Enol Ethers. The Stereoselective Synthesis of Cyclic Ethers.

ChemInform ◽  
2004 ◽  
Vol 35 (40) ◽  
Author(s):  
Christopher M. Jessop ◽  
Andrew F. Parsons ◽  
Anne Routledge ◽  
Derek J. Irvine
Keyword(s):  
Stereoselective Synthesis ◽  
Radical Addition ◽  
Cyclic Ethers ◽  
Enol Ethers ◽  
Phosphonyl Radical

scholarly journals Mineralization of sulfonamides from wastewater using ozone-based systems

2021 ◽  
Author(s):  
T. H. Ho ◽  
C. H. Wu ◽  
T. Y. Han ◽  
W. J. Syu
Keyword(s):  
Steric Hindrance ◽  
Radical Addition ◽  
The Novel ◽  
Mineralization Rate ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order ◽  
Uv Ozone ◽  
Heterocyclic Group

Abstract Ozone, UV/ozone, ozone/persulfate (PS) and UV/ozone/PS systems were used to mineralize sulfonamides. Sulfadiazine (SDZ), sulfamerazine (SMR) and sulfamethazine (SMZ) were the target compounds. The novel contribution of this study is its determination of the effects of PS addition, sulfonamide structure, pH and salinity on sulfonamide mineralization in ozone-based systems. The mineralization rate of sulfonamides satisfied pseudo-first-order kinetics. The SMZ mineralization rate constant in ozone, UV/ozone, ozone/PS and UV/ozone/PS systems at pH 5 were 0.0058; 0.0101; 0.0069 and 0.0802 min−1, respectively, and those at pH 7 were 0.0075; 0.0116; 0.0083 and 0.0873 min−1, respectively. The increase in the number of methyl-substituents in the heterocyclic group of SMZ and the corresponding increase in the steric hindrance of radical addition, reduced mineralization rates below those of SMR and SDZ. The addition of PS promoted sulfonamide mineralization in the ozone-based systems; conversely, salinity inhibited sulfonamide mineralization.

scholarly journals Controlling alkyne reactivity by means of a copper-catalyzed radical reaction system for the synthesis of functionalized quaternary carbons

2020 ◽  
Vol 16 ◽  
pp. 502-508
Author(s):  
Goki Hirata ◽  
Yu Yamane ◽  
Naoya Tsubaki ◽  
Reina Hara ◽  
Takashi Nishikata
Keyword(s):  
Alkyl Radical ◽  
Copper Catalyst ◽  
Radical Reaction ◽  
Reaction System ◽  
Radical Addition ◽  
Terminal Alkyne ◽  
Multiple Bonds ◽  
Complex Molecules ◽  
Reaction Patterns ◽  
Tertiary Alkyl

A terminal alkyne is one of the most useful reactants for the synthesis of alkyne and alkene derivatives. Because an alkyne undergoes addition reaction at a C–C triple bond or cross-coupling at a terminal C–H bond. Combining those reaction patterns could realize a new reaction methodology to synthesize complex molecules including C–C multiple bonds. In this report, we found that the reaction of 3 equivalents of terminal alkyne 1 (aryl substituted alkyne) and an α-bromocarbonyl compound 2 (tertiary alkyl radical precursor) undergoes tandem alkyl radical addition/Sonogashira coupling to produce 1,3-enyne compound 3 possessing a quaternary carbon in the presence of a copper catalyst. Moreover, the reaction of α-bromocarbonyl compound 2 and an alkyne 4 possessing a carboxamide moiety undergoes tandem alkyl radical addition/C–H coupling to produce indolinone derivative 5.

Manganese(iii)-mediated alkenyl Csp2–P bond formation from the reaction of β-nitrostyrenes with dialkyl phosphites

2015 ◽  
Vol 13 (17) ◽  
pp. 4896-4902 ◽  
Author(s):  
Jian-Fei Xue ◽  
Shao-Fang Zhou ◽  
Ye-Ye Liu ◽  
Xiangqiang Pan ◽  
Jian-Ping Zou ◽  
...  
Keyword(s):  
Bond Formation ◽  
Radical Addition ◽  
Dialkyl Phosphites ◽  
Phosphonyl Radical

Mn(OAc)3-mediated tandem phosphonyl radical addition to β-nitrostyrenes followed by denitration to form (E)-2-alkenyl phosphonates is described.

scholarly journals Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

2013 ◽  
Vol 9 ◽  
pp. 1148-1155 ◽  
Author(s):  
Hideto Miyabe ◽  
Ryuta Asada ◽  
Yoshiji Takemoto
Keyword(s):  
Lewis Acid ◽  
Triple Bond ◽  
Radical Reaction ◽  
Cascade Reaction ◽  
Radical Addition ◽  
Radical Acceptor ◽  
Chiral Lewis Acid ◽  
Intermolecular Reaction ◽  
High Level

The limitation of hydroxamate ester as a chiral Lewis acid coordination moiety was first shown in an intermolecular reaction involving a radical addition and sequential allylation processes. Next, the effect of hydroxamate ester was studied in the cascade addition–cyclization–trapping reaction of substrates with a carbon–carbon triple bond as a radical acceptor. When substrates with a methacryloyl moiety and a carbon–carbon triple bond as two polarity-different radical acceptors were employed, the cascade reaction proceeded effectively. A high level of enantioselectivity was also obtained by a proper combination of chiral Lewis acid and these substrates.

Et3B-Induced Radical Addition of Diphenylphosphine Oxide to Unsaturated Compounds.

ChemInform ◽  
2003 ◽  
Vol 34 (47) ◽  
Author(s):  
Patrick Rey ◽  
Jacques Taillades ◽  
Jean Christophe Rossi ◽  
Georges Gros
Keyword(s):  
Radical Addition ◽  
Diphenylphosphine Oxide ◽  
Unsaturated Compounds

Phosphonyl radical addition to enol ethers. The stereoselective synthesis of cyclic ethers

2004 ◽  
Vol 45 (26) ◽  
pp. 5095-5098 ◽  
Author(s):  
Christopher M. Jessop ◽  
Andrew F. Parsons ◽  
Anne Routledge ◽  
Derek J. Irvine
Keyword(s):  
Stereoselective Synthesis ◽  
Radical Addition ◽  
Cyclic Ethers ◽  
Enol Ethers ◽  
Phosphonyl Radical

Radical addition to ynol ethers — A convenient procedure for the stereoselective preparation of α-iodo enol ethers in neutral conditions

2008 ◽  
Vol 86 (10) ◽  
pp. 970-975 ◽  
Author(s):  
Fanny Longpré ◽  
Natalia Rusu ◽  
Maxime Larouche ◽  
Rana Hanna ◽  
Benoit Daoust
Keyword(s):  
Radical Reaction ◽  
Radical Addition ◽  
Reaction Conditions ◽  
Neutral Radical ◽  
Enol Ethers ◽  
Convenient Procedure ◽  
Different Temperatures ◽  
Ynol Ethers ◽  
Neutral Conditions ◽  
High Stereoselectivity

α-Iodo enol ethers, precursors of acyl anion equivalents, are not easily prepared. Herein we report that addition of activated iodoalkanes to ynol ethers under mild and neutral radical reaction conditions leads to α-iodo enol ethers in moderate to excellent yields with high stereoselectivity. The reaction can be carried out in various solvents at different temperatures. The methodology allows the preparation of β-alkylated and β,β-dialkylated α-iodo enol ethers. Reduction of the carbon-iodine bond of these species leads to the corresponding enol ethers with good yields.Key words: ynol ethers, enol ethers, radical addition, stereoselective.

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