柱芳烃综述1
合集下载
相关主题
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
Chem. Soc. Rev.
View Online
Downloaded by Shanghai University on 23 August 2011 Published on 29 July 2011 on http://pubs.rsc.org | doi:10.1039/C1CS15164A
School of Pharmacy and Biomolecular Sciences, Huxley Building, University of Brighton, Brighton BN2 4GJ, UK. E-mail: P.J.Cragg@brighton.ac.uk; Fax: +44 1273 642647; Tel: +44 1273 642037 w Electronic supplementary information (ESI) available: conformational analysis of pillar[5]arenes, through-the-annulus rotation mechanisms and a note on cyclophane synthesis. See DOI: 10.1039/ c1cs15164a
An alternative convergent synthesis of [15]paracyclophane was attempted, however, this gave an even lower yield in the final step. The authors stated that:
Pellagrin in 18994 and cyclodextrins observed by Villiers in 1891.5 Calixarenes, resorcinarenes and calixpyrroles all date back to Baeyer’s work on phenol-formaldehyde chemistry in the 1870’s and 1880’s.6,7 It came as a surprise when, in 2008, a new class of macrocycles, the pillar[n]arenes, appeared in the literature.8 In the short time since their discovery the chemistry of these fascinating macrocycles has developed rapidly with new synthetic routes pursued, a wealth of inclusion phenomena described, and the preparation of the first pillar[5]arenebased molecular sensor. Their unusual symmetry has led to some distinctive geometrical features and stereochemistry with implications for their use in molecular recognition. This tutorial review will provide a summary of research into the cyclopentameric pillar[5]arenes.
Peter J. Cragg
Peter J. Cragg started his career in macrocyclic chemistry as a graduate student in the Atwood group at the University of Alabama. After a year as a postdoctoral researcher at SUNY Stony Brook, and a further 18 months at Reading University, he joined the University of Brighton in 1993 where he is currently Reader in Supramolecular and Bioinorganic Chemistry. His research interests include biomimetic artificial ion channels, computational chemistry and macrocyclic synthesis.
Structures, conformers and chirality
Pillar[n]arenes, named by Ogoshi and Nakamoto in their 2008 paper,8 are 1,4-disubstituted [1n]paracyclophanes derived from hydroquinones linked by methylene bridges in the 2,5positions. In this they are structurally related to [15]paracyclophane reported in 1985 by Gribble and Nutaitis.9 [1n]Paracyclophanes were prepared from linear precursors terminating in a benzyl alcohol, as shown in Scheme 1. In the case of the linear pentamer this involved 14 steps and an overall yield of 13% prior to cyclisation Macrocycles were successfully prepared from the linear pentamer and hexamer, but not the tetramer, with [16]paracyclophane isolated in 31% yield and [15]paracyclophane in 10% yield. The final cyclisation step occurred via a Friedel–Crafts reaction, unusual in that most routes to [1n]paracyclophanes require that one of the aromatic rings is formed following cyclisation of a less strained precursor.10
Chem Soc Rev
View Online
Dynamic Article Links
Downloaded by Shanghai University on 23 August 2011 PLeabharlann Baidublished on 29 July 2011 on http://pubs.rsc.org | doi:10.1039/C1CS15164A
Cite this: DOI: 10.1039/c1cs15164a www.rsc.org/csr
TUTORIAL REVIEW
Pillar[5]arenes: fascinating cyclophanes with a bright futurew
Peter J. Cragg* and Kushal Sharma
Introduction
It is rare that chemists can announce the arrival of a new class of synthetic, functional macrocycles. Crown ethers date back to Pedersen’s work in 19671 and phthalocyanines to the discoveries made by Dandridge2 in the 1920’s. Cucurbiturils were first prepared in 1905,3 metacyclophanes reported by
This journal is c The Royal Society of Chemistry 2011
Kushal Sharma
Kushal Sharma received his BSc (Hons) in Pharmaceutical and Chemical Sciences from the University of Brighton before spending a year in industrial formulation. In 2010 he started postgraduate research in the University of Brighton’s Huxley Building laboratories focusing on artificial ion channels incorporating calix[4]arenes, oxacalix[3]arenes and pillar[5]arenes.
Received 14th June 2011 DOI: 10.1039/c1cs15164a
Pillar[5]arenes are [15]paracyclophane derivatives consisting of 1,4-disubstituted hydroquinones linked by methylene bridges in the 2,5-positions. The first report of these novel macrocycles was in 2008, when 1,4-dimethoxypillar[5]arene was prepared in 22% yield, and subsequent improvements in synthetic methods have allowed the number of derivatives to expand significantly. In addition to D5 symmetric pillar[5]arenes, asymmetric pillar[5]arenes with two different substituents in the 1- and 4-positions and copillar[5]arenes consisting of two different repeat units in a 4 : 1 ratio have been synthesised. Crystallographic, computational and spectroscopic studies are starting to shed light on the compounds’ unusual inclusion phenomena, from gelation and transportation of water through nanotubes to the formation of chromogenic rotaxanes. Applications as molecular sensors are starting to appear with a focus on guest detection by fluorescence quenching. This tutorial review will provide a summary of research into the pillar[5]arenes since their recent discovery.
View Online
Downloaded by Shanghai University on 23 August 2011 Published on 29 July 2011 on http://pubs.rsc.org | doi:10.1039/C1CS15164A
School of Pharmacy and Biomolecular Sciences, Huxley Building, University of Brighton, Brighton BN2 4GJ, UK. E-mail: P.J.Cragg@brighton.ac.uk; Fax: +44 1273 642647; Tel: +44 1273 642037 w Electronic supplementary information (ESI) available: conformational analysis of pillar[5]arenes, through-the-annulus rotation mechanisms and a note on cyclophane synthesis. See DOI: 10.1039/ c1cs15164a
An alternative convergent synthesis of [15]paracyclophane was attempted, however, this gave an even lower yield in the final step. The authors stated that:
Pellagrin in 18994 and cyclodextrins observed by Villiers in 1891.5 Calixarenes, resorcinarenes and calixpyrroles all date back to Baeyer’s work on phenol-formaldehyde chemistry in the 1870’s and 1880’s.6,7 It came as a surprise when, in 2008, a new class of macrocycles, the pillar[n]arenes, appeared in the literature.8 In the short time since their discovery the chemistry of these fascinating macrocycles has developed rapidly with new synthetic routes pursued, a wealth of inclusion phenomena described, and the preparation of the first pillar[5]arenebased molecular sensor. Their unusual symmetry has led to some distinctive geometrical features and stereochemistry with implications for their use in molecular recognition. This tutorial review will provide a summary of research into the cyclopentameric pillar[5]arenes.
Peter J. Cragg
Peter J. Cragg started his career in macrocyclic chemistry as a graduate student in the Atwood group at the University of Alabama. After a year as a postdoctoral researcher at SUNY Stony Brook, and a further 18 months at Reading University, he joined the University of Brighton in 1993 where he is currently Reader in Supramolecular and Bioinorganic Chemistry. His research interests include biomimetic artificial ion channels, computational chemistry and macrocyclic synthesis.
Structures, conformers and chirality
Pillar[n]arenes, named by Ogoshi and Nakamoto in their 2008 paper,8 are 1,4-disubstituted [1n]paracyclophanes derived from hydroquinones linked by methylene bridges in the 2,5positions. In this they are structurally related to [15]paracyclophane reported in 1985 by Gribble and Nutaitis.9 [1n]Paracyclophanes were prepared from linear precursors terminating in a benzyl alcohol, as shown in Scheme 1. In the case of the linear pentamer this involved 14 steps and an overall yield of 13% prior to cyclisation Macrocycles were successfully prepared from the linear pentamer and hexamer, but not the tetramer, with [16]paracyclophane isolated in 31% yield and [15]paracyclophane in 10% yield. The final cyclisation step occurred via a Friedel–Crafts reaction, unusual in that most routes to [1n]paracyclophanes require that one of the aromatic rings is formed following cyclisation of a less strained precursor.10
Chem Soc Rev
View Online
Dynamic Article Links
Downloaded by Shanghai University on 23 August 2011 PLeabharlann Baidublished on 29 July 2011 on http://pubs.rsc.org | doi:10.1039/C1CS15164A
Cite this: DOI: 10.1039/c1cs15164a www.rsc.org/csr
TUTORIAL REVIEW
Pillar[5]arenes: fascinating cyclophanes with a bright futurew
Peter J. Cragg* and Kushal Sharma
Introduction
It is rare that chemists can announce the arrival of a new class of synthetic, functional macrocycles. Crown ethers date back to Pedersen’s work in 19671 and phthalocyanines to the discoveries made by Dandridge2 in the 1920’s. Cucurbiturils were first prepared in 1905,3 metacyclophanes reported by
This journal is c The Royal Society of Chemistry 2011
Kushal Sharma
Kushal Sharma received his BSc (Hons) in Pharmaceutical and Chemical Sciences from the University of Brighton before spending a year in industrial formulation. In 2010 he started postgraduate research in the University of Brighton’s Huxley Building laboratories focusing on artificial ion channels incorporating calix[4]arenes, oxacalix[3]arenes and pillar[5]arenes.
Received 14th June 2011 DOI: 10.1039/c1cs15164a
Pillar[5]arenes are [15]paracyclophane derivatives consisting of 1,4-disubstituted hydroquinones linked by methylene bridges in the 2,5-positions. The first report of these novel macrocycles was in 2008, when 1,4-dimethoxypillar[5]arene was prepared in 22% yield, and subsequent improvements in synthetic methods have allowed the number of derivatives to expand significantly. In addition to D5 symmetric pillar[5]arenes, asymmetric pillar[5]arenes with two different substituents in the 1- and 4-positions and copillar[5]arenes consisting of two different repeat units in a 4 : 1 ratio have been synthesised. Crystallographic, computational and spectroscopic studies are starting to shed light on the compounds’ unusual inclusion phenomena, from gelation and transportation of water through nanotubes to the formation of chromogenic rotaxanes. Applications as molecular sensors are starting to appear with a focus on guest detection by fluorescence quenching. This tutorial review will provide a summary of research into the pillar[5]arenes since their recent discovery.