133744-83-9Relevant academic research and scientific papers
Synthesis, Optical Resolution and Complexation Properties of Inherently Chiral Monoalkylated p-tert-Butyl-(1,2)-calix[4]crown Ethers
Arnaud-Neu, Fran?oise,Caccamese, Salvatore,Fuangswasdi, Saowarux,Pappalardo, Sebastiano,Paris, Melchiorre F.,Petringa, Ada,Principato, Grazia
, p. 8041 - 8048 (1997)
Reaction of mono-O-alkylated calix[4]arenes 2 with tri- to pentaethylene glycol ditosylates and K2CO3 affords asymmetrical (1,2)-calix[4]crown ether derivatives 3 as the main product, along with minor amounts of calix[4]arene dimers 4 and mixed syn-distal di-O-alkylated calix[4]arenes 5. A reaction mechanism for the formation of 3-5 is proposed, and the NMR spectral features of these products are briefly discussed. Evidence of the chirality of 3 was provided by diastereomeric interaction with enantiopure alkylammonium salts. The enantiomeric resolution of racemates 3 was achieved by direct HPLC separation, using chiral stationary phases. A screening of the complexing abilities of pyridino-(1,2)-calix[4]crown ethers 3a-c by extraction studies from water into CH2Cl2 showed a low extraction level of alkali, alkaline earth, and heavy metal picrates, while up to 25% extraction was found for Ag+. UV and pH-metric measurements of 3a-c with silver picrate in THF indicate the formation of 1:1:1 (metal:ligand:picrate) species, with log K's in the range 3.1-3.7.
Easy and selective method for the synthesis of Mono-, di-, tri-, tetra-O-arylmethyl-p-t-butylcalix[4]arenes
Xie, Yuanyuan,Xia, Wang
experimental part, p. 402 - 406 (2012/09/21)
Mono-, di-, tri- and tetra-O-arylmethyl-p-t-butylcalix[4]arenes were synthesised respectively from p-t-butylcalix[4]arene and arylmethyl bromide through an easy and selective one-step reaction. Mono- and di-arylmethyl ethers of p-t-butylcalix[4]arenes wer
Regioselective monoalkylation of calixarenes. Synthesis of homodimer calixarenes
Santoyo-Gonzalez, Francisco,Torres-Pinedo, Antonio,Sanchez-Ortega, Adolfo
, p. 4409 - 4414 (2007/10/03)
The selective monoalkylation at the smaller (lower) rim of the p-tert- butylcalix[4]- and -[6]arenes using bis(butyltin)oxide and different alkylating agents is described. The procedure is remarkable for the mild conditions used allowing an efficiently access to monoalkylated calixarene derivatives in moderate to good yields. Monoalkynylcalix[4]arene and monoalkynylcalix[6]arene have been synthetically exploited for the synthesis of bis-calix[n]arenes (n = 4, 6) with a diyne bridge by oxidative coupling of alkynes. In addition, intermolecular methathesis of the obtained monoalkenylcalix[4]arene allowed the preparation of bis-calix[4]arene that are single bridged at the smaller (lower) rim with a 2-butenyl moiety.
Syntheses of New Isomers from p-t-Butylcalixarene. Strategies for Regioselective Alkylation on the Lower Rim
Iwamoto, Koji,Yanagi, Akihiro,Araki, Koji,Shinaki, Seiji
, p. 473 - 476 (2007/10/02)
By using a protection-deprotection technique and metal template effects, a number of new regio- and conformational isomers were synthesized.
Syntheses of all possible conformational isomers of O-alkyl-p-t-butylcalix[4]arenes
Iwamoto, Koji,Araki, Koji,Shinkai, Seiji
, p. 4325 - 4342 (2007/10/02)
In p-t-butylcalix[4]arene (1H4) and its mono-, di-, tri-, and tetra-O-alkyl derivatives (1HR3, 1H2R2, 1HR3, and 1R4 respectively), 23 different homologs can exist (including 1H4)
How is the 1,2-Alternate Conformer Formed in Tetra-O-alkylation of p-tert-Butylcalixarene?
Iwamoto, Koji,Araki, Koji,Shinkai, Seiji
, p. 1611 - 1613 (2007/10/02)
The reaction route for the formation of a new 1,2-alternate conformer from p-tert-butylcalixarene has been elucidated.
