Synthesis and crystal structures of new chiral 3-amino-2H-azirines and the Pd com­plex of one of them

3-Amino-2H-azirines are potentially versatile building blocks in heterocyclic and peptide synthesis. Three new 3-amino-2H-azirines have been synthesized as racemates or mixtures of diastereoisomers in cases where another chiral residue is incorporated as the exocyclic amine. The crystal structures of two of them, an approximately 1:1 diastereoisomeric mixture of (2R)- and (2S)-2-ethyl-3-[(2S)-2-(1-meth­oxy-1,1-di­phenyl­meth­yl)pyrrolidin-1-yl]-2-methyl-2H-azirine, C(23)H(28)N(2)O, 11, and 2-benzyl-3-(N-methyl-N-phenyl­amino)-2-phenyl-2H-azirine, C(22)H(20)N(2), 12, and the third as its diastereoisomeric trans-PdCl(2) com­plex, trans-di­chlorido­[(2R)-2-ethyl-2-methyl-3-(X)-2H-azirine][(2S)-2-ethyl-2-methyl-3-(X)-2H-azirine]palladium(II), where X = N-{[(1S,2S,5S)-6,6-di­methylbi­cyclo­[3.1.1]heptan-2-yl]meth­yl}-N-phenyl­amino, [PdCl(2)(C(21)H(30)N(2))(2)], 14, have been determined and the geometries of the azirine rings com­pared with those of 11 other 3-amino-2H-azirine structures reported in the literature. Most notable is the very long formal N—C single bond, which is, with one exception, around 1.57 Å. Each com­pound has crystallized in a chiral space group. The Pd atom in the trans-PdCl(2) com­plex is coordinated by one of each of the pair of diastereoisomers, while both of the diastereoisomers share the same crystallographic site in the structure of 11; this property thereby manifesting itself as disorder. The chosen crystal of 12 is either an inversion twin or com­posed of a pure enanti­omorph, but this could not be established specifically.