Stereofacial Assembly of Engineered Multichiral Aziridines via B/Si Ylide Insertion

Halo-borylsilylcarbanion reagents can be added, with complete stereofacial control, to chiral <i>N</i>-<i>tert</i>-butanesulfinyl imines, featuring an asymmetric C-C bond, followed by concomitant intramolecular asymmetric C-N bond formation. There is exclusive access to α,α-B,Si-disubstituted aziridine units containing up to four contiguous stereocenters in a single operation. In addition, complete stereochemical discrimination has been observed in <i>N</i>-<i>tert</i>-butanesulfinyl alkyl aldimines. Post-transformation of B,Si-disubstituted aziridine generates multichiral aziridine scaffolds.