Synthesis Of Calix[4]pyrrole And Its Derivatives

Supramolecular chemistry plays a pivotal role in the field of chemistry and is one of the most important topics for scientists today.In the host-guest system of supramolecular chemistry,molecular recognition is the selective binding of host molecules to guest molecules in a specific manner.Molecular recognition is a process in which the synergy between intermolecular forces makes the host-guest molecules fit together.In fact,it means that the non-covalent interactions between molecules depend on the macrocyclic effect or the chelation effect to make the force,and finally reach the consensus.The size,shape and coordination number of the host molecular cavity affect the recognition of the guest molecule.The calix[4]pyrrole is a macrocyclic compound composed of four pyrrole and sp3 hybridized carbon atoms,and multiple Imino groups in four interconnected pyrrole cavities can form hydrogen bonds with guest molecules,making calix[4]pyrrole different from other host molecules in terms of its configuration and properties.These advantages of calix[4]pyrrole allow it to specifically accomplish the selective recognition of anions.In this work,N-Boc-4-acetylpiperidine,1-indanone and other carbonyl compounds were used as starting materials to synthesize the corresponding calix[4]pyrrole,and its modification was the research focus.The work is divided into the following.three parts:(1)N-Boc-4-acetylpiperidine was synthesized from N-Boc-4-piperidinecarboxylic acid and isopropylidene malonate,and then condensed with pyrrole by methanesulfonic acid in methanol solvent.Meso–tetramethyl –meso-tetrapiperidinyl-calix[4]pyrrole compounds 2-4 and 2-5 were synthesized and the reaction conditions were optimized.Then using meso-tetramethyl-meso-tetrapiperidinyl-calix[4]pyrrole 2-5 and methyl pyruvate,methyl methacrylate,acrylonitrile,hydroxyethyl acrylate,2(5H)furanone as raw materials The Michael addition reaction was carried out using K2CO3 as a catalyst in a methanol solvent to produce compounds 2-6,2-7,2-8,2-9,2-10,and the reaction was optimized by microwave to shorten the reaction.Time and increase the reaction yield.(2)The corresponding 5-substituted-1-indolone compound 3-4 were synthesized by 3-hydroxypropionyl chloride and benzene or substituted benzene as a raw material,catalyzed by Lewis acid,and subjected to acylation and alkylation.The novel Al Cl3-Li Cl molten salt system was selected as the Lewis alkylation Lewis acid catalyst and the reaction solvent to determine and optimize the synthesis conditions of these compounds.Meanwhile,A new type of calix[4]pyrrole 3-5 was synthesized by the 1-anthone and pyrrole as the raw materials,catalyzed by methanesulfonic acid.catalysis.The ability of the calix[4]pyrrole 3-5 to recognize anions was investigated by UV titration and NMR titration.(3)A series of new type calix[4] pyrrole 4-1,4-2,4-3 with other functional groups were synthesized by using methyl pyruvate,acetol and pyrrole as raw materials and condensing the ring under the catalysis of methanesulfonic acid.All of the above the compounds were characterized by 1H NMR,13 C NMR.And some were characterized by ESI-HRMS.