title: Template-induced diverse metal-organic materials as catalysts for the tandem acylation-Nazarov cyclization.
abstract: In our continuing quest to develop a metal-organic framework (MOF)-catalyzed tandem pyrrole acylation-Nazarov cyclization reaction with α,β-unsaturated carboxylic acids for the synthesis of cyclopentenone[b]pyrroles, which are key intermediates in the synthesis of natural product (±)-roseophilin, a series of template-induced Zn-based (1-3) metal-organic frameworks (MOFs) have been solvothermally synthesized and characterized. Structural conversions from non-porous MOF 1 to porous MOF 2, and back to non-porous MOF 3 arising from the different concentrations of template guest have been observed. The anion-π interactions between the template guests and ligands could affect the configuration of ligands and further tailor the frameworks of 1-3. Futhermore, MOFs 1-3 have shown to be effective heterogeneous catalysts for the tandem acylation-Nazarov cyclization reaction. In particular, the unique structural features of 2, including accessible catalytic sites and suitable channel size and shape, endow 2 with all of the desired features for the MOF-catalyzed tandem acylation-Nazarov cyclization reaction, including heterogeneous catalyst, high catalytic activity, robustness, and excellent selectivity. A plausible mechanism for the catalytic reaction has been proposed and the structure-reactivity relationship has been further clarified. Making use of 2 as a heterogeneous catalyst for the reaction could greatly increase the yield of total synthesis of (±)-roseophilin.
authors.affiliation: The College of Chemistry and, Molecular Engineering, Zhengzhou University, Henan 450052 (P.R. China), Fax: (+86) 371-67761744.
authors.forename: Chao
authors.initials: C
authors.lastname: Huang
authors.forename: Ran
authors.initials: R
authors.lastname: Ding
authors.forename: Chuanjun
authors.initials: C
authors.lastname: Song
authors.forename: Jingjing
authors.initials: J
authors.lastname: Lu
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.forename: Xiao
authors.initials: X
authors.lastname: Han
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Hou
authors.forename: Yaoting
authors.initials: Y
authors.lastname: Fan
mesh_terms: D000215:Acylation; D002384:Catalysis; D003500:Cyclization; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D006575:Heterocyclic Compounds, 3-Ring; D009942:Organometallic Compounds; D011758:Pyrroles; C408872:roseophilin; D015032:Zinc
keywords: heterogeneous catalysis; metal-organic frameworks; self-assembly; structure-activity relationships; template synthesis