Applications of oxaziridines in organic synthesis

The SAMP-/RAMP-hydrazone methodology in asymmetric synthesis

This account reviews our efforts over the past 37 years to understand the chemistry of a select group of sulfur−nitrogen compounds including sulfinimines (N-sulfinyl imines) and N-sulfonyloxaziridines. Our early exploration of the thermal properties of sulfenamides, a class of sulfur−nitrogen compounds about which little was known, resulted in a new procedure, the silver-assisted method, for the construction of sulfenimines (N-sulfenyl imines). Selective oxidations of these compounds resulted in the production of N-sulfinyl imines (sulfinimines) and N-sulfonyloxaziridines. N-Sulfonyloxaziridines turned out to be a new class of aprotic neutral oxidizing reagents. Enantiomerically pure examples afford high ee values in the oxidation of enolates to α-hydroxy carbonyl compounds and in the oxidation of sulfides and selenides to sulfoxides and selenoxides. Additions of organometallic reagents to enantiomerically pure sulfinimines provide the best and most versatile method for the asymmetric construction of the ...

Adventures in sulfur-nitrogen chemistry.

Strategies for the total synthesis of complex natural products that contain two or more contiguous stereogenic quaternary carbon atoms in their intricate structures are reviewed with 12 representative examples. Emphasis has been put on methods to create quaternary carbon stereocenters, including syntheses of the same natural product by different groups, thereby showcasing the diversity of thought and individual creativity. A compendium of selected natural products containing two or more contiguous stereogenic quaternary carbon atoms and key reactions in their total or partial syntheses is provided in the Supporting Information.

/pdf/synthetic-strategies-toward-natural-products-containing-20bttg89an.pdf

Synthetic Strategies toward Natural Products Containing Contiguous Stereogenic Quaternary Carbon Atoms.

Advances in Asymmetric Enolate Methodology

Cette methode fournit les acyloines avec des rendements eleves et une excellente stereoselectivite

Synthesis of .alpha.-hydroxycarbonyl compounds (acyloins): direct oxidation of enolates using 2-sulfonyloxaziridines

Asymmetric synthesis of α-hydroxy carboxylic acids: direct oxidation of chiral amide enolates using 2-sulfonyloxaziridines

(±)-trans-2-(phenylsulfonyl)-3-phenyloxaziridine 



intermediate: N-Benzylidenebenzenesulfonamide.




product: (±)-trans-2-(Phenylsulfonyl)-3-phenyloxaziridine.




product: R = Ph, Ar = 3NO2Ph




product: R = Ph, Ar = 4NO2Ph




product: R = Me, Ar = Ph




product: R = PhCH2, Ar = Ph





Keywords:

addition, to CO;
annulation, heterocyclic-[3];
oxidation, CN  oxaziridine;
benzene;
2-(phenylsulfonyl)-3-phenyloxaziridine, decomposition;
dean-stark water separator

Lal C. Vishwakarma

Papers

Synthesis of .alpha.-hydroxycarbonyl compounds (acyloins): direct oxidation of enolates using 2-sulfonyloxaziridines

Asymmetric synthesis of α-hydroxy carboxylic acids: direct oxidation of chiral amide enolates using 2-sulfonyloxaziridines

(±)-trans-2-(Phenylsulfonyl)-3-phenyloxaziridine