title: Synthesis of 9,10-bis-ketoenaminoanthryl and 9,10-bis-isoxazolylanthryl linked biscalix[4]arenes: atropisomers and molecular recognitions.
abstract: An efficient synthetic pathway for the synthesis of biscalix[4]arenes 5-10 using 1,3-dipolar cycloaddition reactions is reported. Biscalix[4]arene 10 is capable of forming a complex with methyl viologen because of favorable cation-π interactions and a proper cavity size to accommodate the guest. Moreover, biscalix[4]arenes 8a and 8b were found to be atropisomers at room temperature. These two conformers were unable to exchange at room temperature because of the restricted rotation of the C(9)-C(11) or C(10)-C(12) bonds of the β-amino-α,β-unsaturated ketones of anthracene.
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan 30050, Republic of China.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Tsai
authors.forename: I-Ting
authors.initials: IT
authors.lastname: Ho
authors.forename: Jean-Ho
authors.initials: JH
authors.lastname: Chu
authors.forename: Li-Ching
authors.initials: LC
authors.lastname: Shen
authors.forename: Shou-Ling
authors.initials: SL
authors.lastname: Huang
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Chung