Syntheses and conformations of tetrahomodioxacalix[4]arene tetraamides and tetrathioamides.
A series of tetrahomodioxacalix[4]arene tetraamides and tetrathioamides with four p-phenyl groups on their upper rim were synthesized. From the (1)H and (13)C NMR and crystal structure, N-butylamido homooxacalix[4]arene (4) was found to be in the 1,3-alternate conformation and has intramolecular hydrogen bonding between N-H and facing oxygen atoms of the carbonyl O=C group. This hydrogen bonding decreased the metal ion complex ability. Transformation of the 1,3-alternate N-butylamido (4) into N-butylthioamido homooxacalix[4]arene (5) using Lawesson's reagent gave a conformational change to the C-1,2-alternate.
No
Kwanghyun
K
Department of Chemistry, Sookmyung Women's University, Seoul 140-742, Korea.
Lee
Jeong Hyeon
JH
Yang
Seung Hwan
SH
Yu
Sang Hyeok
SH
Cho
Moon Hwan
MH
Kim
Moon Jib
MJ
Kim
Jong Seung
JS