Selective hydroxyl replacement in calixarenes: amino-, azo-, and xanthenocalixarene derivatives.
摘要:
The synthesis of monoamino-, azo-, and xanthenocalixarenes and dehydroxylated calixarenes via condensation, reduction, or rearrangement of monospirodienone calixarene derivatives is described. Mild oxidation of p-tert-butylcalix[5]arene and p-tert-butylcalix[6]arene yielded their corresponding monospirodienone derivatives 4b and 4c. Monospirodienone 4b was characterized by X-ray crystallography. Reaction of 4b with (2,4-dinitrophenyl)hydrazine gave a (dinitrophenyl)azo derivative (8), which by reaction with HI gave the monoaminotetrahydroxycalix[5]arene 10. Reaction of 4b with hydrazine/base yielded in a Wolff-Kishner-type reaction, the monodehydroxylated calix[5]arene 8. Reaction of 4b with a methanolic solution of hydrazine at room temperature yielded a derivative characterized by X-ray crystallography as a system with an azo bridge (15). Spirodienone 4b rearranges in MeOH/H+, yielding the xanthene derivative 16 as the main product, together with the linear pentamer 17. The larger spirodienone 4c rearranges by treatment with MeOH/H+, yielding the xanthenocalix[6]arene 18. X-ray diffraction of a crystal of 18 grown in MeCN shows that in the crystal the molecules form intermolecular hydrogen-bonded dimers in which the two molecules mutually include each other; i.e., one of the protuberances of each molecule is located in the V-shaped cavity of its neighboring molecule. Molecules 16 and 18 represent the first examples of calixarene systems incorporating a xanthene moiety.
Selective hydroxyl replacement in calixarenes: amino-, azo-, and xanthenocalixarene derivatives.
作者:Oleg Aleksiuk、Shmuel Cohen、Silvio E. Biali
DOI:10.1021/ja00143a005
日期:1995.9
The synthesis of monoamino-, azo-, and xanthenocalixarenes and dehydroxylated calixarenes via condensation, reduction, or rearrangement of monospirodienone calixarene derivatives is described. Mild oxidation of p-tert-butylcalix[5]arene and p-tert-butylcalix[6]arene yielded their corresponding monospirodienone derivatives 4b and 4c. Monospirodienone 4b was characterized by X-ray crystallography. Reaction of 4b with (2,4-dinitrophenyl)hydrazine gave a (dinitrophenyl)azo derivative (8), which by reaction with HI gave the monoaminotetrahydroxycalix[5]arene 10. Reaction of 4b with hydrazine/base yielded in a Wolff-Kishner-type reaction, the monodehydroxylated calix[5]arene 8. Reaction of 4b with a methanolic solution of hydrazine at room temperature yielded a derivative characterized by X-ray crystallography as a system with an azo bridge (15). Spirodienone 4b rearranges in MeOH/H+, yielding the xanthene derivative 16 as the main product, together with the linear pentamer 17. The larger spirodienone 4c rearranges by treatment with MeOH/H+, yielding the xanthenocalix[6]arene 18. X-ray diffraction of a crystal of 18 grown in MeCN shows that in the crystal the molecules form intermolecular hydrogen-bonded dimers in which the two molecules mutually include each other; i.e., one of the protuberances of each molecule is located in the V-shaped cavity of its neighboring molecule. Molecules 16 and 18 represent the first examples of calixarene systems incorporating a xanthene moiety.
Intramolecular Ar−O−Ar Bond Formation in Calixarenes
作者:Kasim Agbaria、Silvio E. Biali
DOI:10.1021/jo0103468
日期:2001.8.1
are not those connected by the spiro bond in the starting material. Methylation of the phenolic hydroxyl groups of 11d with methyl p-toluenesulfonate/K(2)CO(3) or dimethylsulfate/base afforded its dimethyl and tetramethyl ether derivatives. The parent xanthone calix[6]arene derivative 17b was prepared by O-methylation of the phenol groups followed by CrO(3) oxidation of the xanthene methylene group