Synthesis of oxacalixarenes incorporating nitrogen heterocycles: evidence for thermodynamic control.
[structure: see text] Oxacalix[2]arene[2]hetarenes are formed in a single step by cyclooligomerization of meta-diphenols with meta-dichlorinated azaheterocycles. The high selectivity for cyclic tetramer formation results from thermodynamic product control. Macrocycles as large as oxacalix[5]arene[5]hetarenes have been isolated under nonequilibrating conditions.
Katz
Jeffrey L
JL
Department of Chemistry, Colby College, Waterville, Maine 04901, USA. jlkatz@colby.edu
Geller
Bram J
BJ
Conry
Rebecca R
RR