(+)-(3-Oxocamphorsulphonyl)oxaziridune as a highly stereoselective reagent for the oxidation of sulphides to chiral sulphoxides

Abstract

f E.e. determined with Eu(tfc),. Baseline separation not complete; e.e. 5 5 4%. Mes = 2,4,6-trimethylphenyl; determination of e.e. was impossible with all shift reagents tested; [XIS;' -203" ( c 0.7 in acetone); the work by S.

Synthesis and Structure of a New Chiral Oxaziridine from (3-Oxo-camphorsulfonyl)imine

“…2). The same stereoselectivity has been observed in the case of other camphorsulfonyl-oxaziridines [2,5], obvi- ously for the same reasons. This shielding should also contribute to the high enantioselectivities in the oxi dation reactions of the camphor-type oxaziridines.…”

“…Further crystal structure data have been deposited*. A solution of 22.7 g (100 mmol) (3-oxo-camphorsulfonyl)imine (1) [5] in 200 ml of dichlorom ethane and a solution of 18.6 g (200 mmol) N a H C 0 3 in 100 ml of w ater are cooled to 0 °C. A saturated solu tion of 124 g (200 mmol) 80% commercial mag nesium peroxyphthalate in 200 ml of water is added slowly with vigorous stirring.…”

“…A final, slower oxidation at the imine leads to the oxaziridine 7. W hat remains to be explained, is the slow conver sion of the Baeyer-Villiger product 6 to the ox aziridine 3 which takes place in dimethyl sulfoxide solution [5], A mechanism can be conceived starting with addition of an anion to the imine function and continuing with a rearrangem ent to form the new C -C-bond and the oxaziridine ring. However, this has to be inspected more closely by detailed kinetic measurements.…”

“…for enantioselective oxidations of phos phites, are expected [6]. For the oxidation of sulfides to chiral sulfoxides, the (3-oxo-camphorsulfonyl)-oxaziridine 3 [5] gives the highest enantiom eric ex cess, and is therefore of considerable interest. G en erally, these oxaziridines are prepared from the cor responding N-sulfonyl-imines by oxidation with peracids.…”

Camphor-based CCR5 blocker lead compounds – a computational and experimental approach

“…CO 2 was purchased from Air Liquid. Camphorsulphonyl chloride (CS-Cl) was purchased from Fluka and the camphor compounds CCA-H, CCA-Li, 39 isonitrosocamphor (CI-OH) 40 and 3-oxocamphor-sulfonimide (CSI) 41,42 were prepared according to published procedures.…”