Asymmetric aziridine synthesis by aza-Darzens reaction of N-diphenylphosphinylimines with chiral enolates. Part 1: Formation of cis-aziridines

Enantioselective Binaphthophosphepine‐Promoted [3+2] Annulations of N‐Ts‐ and N‐DPP‐Imines with Allenoates and 2‐Butynoates

“…General: Imines 2a-f [12,18] were prepared from the corresponding aldehydes and diphenylphosphinamide in the presence of TiCl 4 , according to the reported method. [12] Characterization data for the new imine 2c: 1 [19] Phosphane-Catalysed Annulations of Imines 2 with 2-Butynoate.…”

Recent advances in the application of the Oppolzer camphorsultam as a chiral auxiliary

“…Asymmetric aziridine syntheses via aza-Darzens ('ADZ') reactions of N-diphenylphosphinyl ('N-Dpp') imines with chiral enolates obtained from oxazolidinones and a camphorsultam was described by Sweeney et al in 2006. As shown in Scheme 57, (2R)-N-bromoacetylcamphorsultam 225 can be prepared in good yield.…”

“…As shown in Scheme 57, (2R)-N-bromoacetylcamphorsultam 225 can be prepared in good yield. 147 Using LiHMDS, compound 225 was deprotected to provide an a-bromo lithioenolate 226, which was immediately added to a THF solution of N-diphenylphosphinylbenzaldimine (Scheme 58 and Table 21). After aqueous work-up, the aziridinyl sultam 227 was obtained.…”

2.14 Other Condensation Reactions (Knoevenagel, Perkin, Darzens)

“…114 Use of the chiral enolate derived from both antipodes of N-bromoacetyl 2,10-camphorsultam, (2R)-221 and (2S)-221, with N-diphenylphosphinyl aryl and tert-butylimines proceeded in generally good yield to give (2 0 R,3 0 R)-or (2 0 S,2 0 S)-cis-N-diphenylphosphinyl aziridinoyl sultams (222) of high de.…”