An expedient synthesis and conformational features of acylhydrazone macrocycles derived from tartaric acid: evidence of water and pi aromatic hydrogen bond interactions

作者：Skowronek Pawel; Kuncewicz Monika; Brzostowska Malgorzata; Janiak Agnieszka; Rychlewska Urszula; Gawronski Jacek^*

来源：Tetrahedron: Asymmetry , 2012, 23(3-4): 300-305.

DOI：10.1016/j.tetasy.2012.02.010

Tartaric acid dihydrazides with acetal protected hydroxy groups react with terephthalaldehyde to preferentially form [2+2] bisacylhydrazone macrocycles. The structures of these macrocycles display all anti N-N and C=N bonds. Both trans- and cis-C(O)-NH bonds are present in the macrocycle thus allowing the formation of a rather compact macrocyclic structure. The structures of the acylhydrazone macrocycle are shown to be different in the crystal and in the isolated molecule due to the structure determining role of water included in the crystal lattice: in the former all of the O=C-C-H bonds are anti, while in the latter both syn- and anti-bonds are present. Both the non-planarity of the bisacylhydrazone molecules and their chiral interchromophoric interactions contribute to the rotatory power of the molecule. The low-temperature X-ray crystal structure of this compound provides direct evidence for hydrogen bonding between water and the aromatic pi-electrons in the solid state.

• 出版日期2012-2-29