The present invention relates to compounds of formula (I)
wherein X, R
1
, R
2
, R
3
, R
4
and R
5
are as defined herein, which are useful for treating diseases which respond to CXCR2 receptor mediators. Pharmaceutical compositions that contain the compounds and processes for preparing the compounds are also described.
Enantiopure 1-(2-pyridyl)alkyl aziridines were designed as bidentate ligands for asymmetric catalysis. Their synthesis involved the addition of organometallic reagents to the imine prepared from 2-pyridinealdehyde and an enantiopure β-aminoalcohol, followed by cyclisation of the β-aminoalcohol moiety to the aziridine ring. Two such ligands (N–N)* were prepared from (S)-valinol and converted to the