N-phosphinoyl oxaziridines; a new class of oxaziridines

Abstract

Novel stable N-phosphinoyl oxaziridines have been prepared and characterised by n.m.r. and mass spectrometry; they function as oxidants towards phosphines, sulphides, and alkenes.

Advances in the Chemistry of Oxaziridines

“…Oxaziridines bearing N -phosphinoyl groups were first synthesized by Boyd et al 54 This class of oxaziridine is typically accessed via reaction of an aryl oxime with chlorodiphenylphosphine, followed by oxidation of the rearranged N -phosphinoyl imine with m CPBA (Scheme 9 ). These oxaziridines are stable compounds that have a low barrier to nitrogen inversion (∼13 kcal/mol) and exist in the trans configuration.…”

N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

“…A recent set of publications by Beresford describe the use of Cinchona alkaloids 102 and 103 as ligands for chiral amide formation (Scheme 42). 64 In the reaction of Nphosphinoylaldimines derived from aromatic aldehydes with diethylzinc, (R)-104 was formed using (-)-cinchonidine (102), while the enantiomer (S)-104 could be synthesized using (+)-cinchonine (103). Although a large excess of diethylzinc (12 equivalents) and a full equivalent of ligand were necessary to achieve the best results, a variety of chiral aromatic amines could be formed under these conditions.…”

“…N-Phosphinoylimines can be oxidized with m-chloroperbenzoic acid (MCPBA) to generate oxaziridines. 102,103 In the case of imines 190 derived from aromatic aldehydes, a biphasic oxidation system affords chromatographically stable products 191 in 30-50% yields (Scheme 84). With imines 192 formed from dialkyl ketones, an alternative oxidation procedure produces oxaziridines 193 in 55- Jennings and coworkers also prepared some chiral, nonracemic oxaziridines for use in enantioselective synthesis.…”

Anionic Halocuprate(II) Complexes as Catalysts for the Oxaziridine-Mediated Aminohydroxylation of Olefins

“…Second, we were interested in the reactivity of oxaziridines bearing N -substituents that can be removed from the 1,3-oxazolidine products under mild conditions. Oxaziridines bearing N -carbamate12 and N -phosphinoyl13 groups failed to afford aminohydroxylation products. On the other hand, N -nosyl oxaziridines possess reactivity similar to that of the analogous N -benzenesulfonyl oxaziridines and afford products that can be deprotected under conditions much milder than the dissolving metal reduction conditions required for removal of an N -benzenesulfonyl group.…”