Photosensitized one-electron reductive cleavage of a carbon–selenium bond: a novel chemoselective deselenenylation and phenylselenenyl group transfer radical chain reaction
Integrated electrochemical reactors in automated flow systems were utilised for selenenylation reactions. The automation allowed multiple electrochemical reactions of a programmed sequence to be performed in a fully autonomous way. Many functionalised selenenylated products were synthesised in short reaction times in good to high yields.
Oxidative Cleavage of Diselenide by<i>m</i>-Nitrobenzenesulfonyl Peroxide. Novel Method for the Electrophilic Benzeneselenenylations of Olefins and Aromatic Rings
acetic acid, phenol, and anisole could be employed; oxyselenenylated ((Remark: Graphics omitted.) : R=H, Me, Ac, and Ph) and arylselenenylated ((Remark: Graphics omitted.) : R=H and Me) adducts were afforded. Phenol gave oxyselenenylated products in cyclohexene or 1-octene and arylselenenylated products in styrene. Efficient intramolecular cyclizations of unsaturated alcohols and carboxylic acids were
Synthesis of chiral 1,5-disubstituted pyrrolidinones via electrophile-induced cyclization of 2-(3-butenyl)oxazolines derived from (1R,2S)- and (1S,2R)-norephedrine
作者:Iván Kanizsai、Zsolt Szakonyi、Reijo Sillanpää、Matthias D’hooghe、Norbert De Kimpe、Ferenc Fülöp
DOI:10.1016/j.tetasy.2006.11.006
日期:2006.11
Starting from (1R,2S)- and (1S,2R)-norephedrine, enantiomers of the corresponding 2-(3-butenyl)oxazolines were prepared in a two-step process. The cyclization of the intermediate alkenylamides with phenylselenyl bromide afforded cyclic imidates instead of the expected pyrrolidinones. The electrophile-induced cyclizations of 2-alkenyloxazolines with bromine or iodine produced diastereomeric mixtures of
The oxidation of diphenyldiselenide with ammonium peroxydisulphate is a very simple and efficient method to produce phenylselenium cations in the absence of nucleophilic counter ions. The reaction carried out in the presence of an olefin, in acetonitrile or propionitrile containing trifluoromethanesulphonic acid and water afforded the amidoselenenylation products in good yield. The intramolecular
Oxidation of Diphenyl Diselenide with 2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ). A New Method for the Electrophilic Phenylselenenylation of Alkenes under Mild Conditions
The oxidation of diphenyl diselenide with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) represents a convenient mild method to produce a strongly electrophilic phenylselenium reagent. Clean phenylseleno methoxylations and hydroxylations of alkenes containing different types of functional groups can be effected by working in methanol or in acetonitrile and water, respectively. This new electrophilic reagent can also be employed to promote efficient cyclization reactions of alkenols to tetrahydrofurans or of alkenoic acids to lactones.