Hydroxylamines 0-phosphinyl

Treatment of the sulphonate esters of N-phosphinyl-hydroxylamines with a strong base such as methoxide often results in a Lossen-like rearrangement. Thus with methoxide in methanol,... 

A convenient route to j3-phosphorus nitroxides involves the 1,3-addition of trimethylsilyl phosphites (e.g., diethyl) or trimethylsilyl phosphines (e.g., diphenyl) to aldo nitrones (e.g., a-PBN, DMPO), or keto nitrones (e.g., 2-Et-DMPO or 2-Ph-DMPO), to form a-phosphityl- or a-phosphinyl-O-silylhydroxyl-amines. Acidic hydrolysis provides the corresponding hydroxylamines which are easily oxidized to p-phosphorus-nitroxides (690). 

For stereoselective synthesis of a-aminocarbonyl compounds using 0-phosphinyl-hydroxylamines, a few procedures have been developed. Attempted amination of enolates of chiral alkyl 3-hydroxybutanoates with 0-(diphenylphosphinyl)hydroxylamine 4a or with its A,A-diisopropyl derivative 4d were found to be unsuccessful". ... 

A two-step procedure for the oxidation of amines to hydroxylamines involves nucleophilic displacement along the peroxide bond of dibenzoyl peroxide and saponification of the intermediate O-ben-zoylhydroxylamine. Primary and secondary amines have been oxidized in this way (equation 29). Related reactions for transformation of amines to O-(arylsulfonyl)- and O-phosphinyl-hydroxylamines have been described by means of bis(arylsulfonyl) and bis(diphenylphosphinyl) peroxide, respectively 86,87... 

The first organocatalytic asymmetric aziridination reactions of electron-deficient olefins made use of either (i) a chiral tertiary amine combined with a 0-phosphinyl or sulfonyl hydroxylamine for the in situ generation of aminimides as aziridination reagents [133, 134], or (ii) a quaternary salt of cinchona alkaloids in phase-transfer catalysis in combination with ethyl nosyloxycarbamate [135], A-acyl A-aryl... 

J, N-DialkyIhydroxylamines were obtained following hydrolyses of IJ-dialkyl-o -diphenylphosphiny 1 hydroxylamines which were in turn prepared by addition of secondary amines to bis[diphenyl-phosphinyl]peroxide at -40°C in alcohol-free chloroform (Scheme... 

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