[12]Annulynes from 1,5‐Hexadiyne and Potassium <i>tert</i>‐Butoxide? Franz Sondheimer’s Hexadienynes!

Christl, Manfred; Hopf, Henning

doi:10.1002/anie.200901741

Angew Chem Int Ed

2010

DOI: 10.1002/anie.200901741

|View full text |Cite

[12]Annulynes from 1,5‐Hexadiyne and Potassium tert‐Butoxide? Franz Sondheimer’s Hexadienynes!

Manfred Christl

Henning Hopf

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2010

2015

Publication Types

Select...

Article4

Relationship

Self Cite1

Independent3

Authors

Journals

Cited by 4 publications

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

Christl

Cohrs

2015

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

A new synthesis of 2,3‐dihydro‐1,3‐methano‐1H‐indene (3) has been designed with bicyclo[2.1.1]hex‐2‐ene serving as starting material, which was added onto chloro‐substituted α‐pyrones. The title hydrocarbon 3 was then obtained in two subsequent steps. The AA′MM′ 1H NMR spectrum of 3 was analyzed and simulated, leading to corrections of previously published coupling constants. The 13C NMR signal of the methylene carbon atoms appears at particularly low field (δ = 63.3 ppm). This finding is discussed together with anomalous low‐ and high‐field absorptions of methylene carbon atoms of cyclobutanes and bridgehead carbon atoms of bicyclo[1.1.0]butanes, the 1,3‐ and 2,4‐positions of which, respectively, are bridged by π electron systems. As a result, moieties with (4n + 2) π electrons cause deshieldings, whereas those having 4n π electrons evoke shieldings.

show abstract

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

Christl

Cohrs

2015

Eur J Org Chem

Self Cite

View full text Add to dashboard Cite

show abstract

Mechanisms and Möbius strips: understanding dynamic processes in annulenes

Castro

Karney

2012

J of Physical Organic Chem

View full text Add to dashboard Cite

Exploratory computational studies on annulenes with planar, Möbius, and two‐twist topologies have resulted in new mechanisms to explain facile thermal configuration change (cis‐trans isomerization) for medium‐sized annulenes ([12]‐ to [16]annulene). Möbius π‐bond shifting through both aromatic and antiaromatic transition states, two‐twist π‐bond shifting, and planar nondegenerate π‐bond shifting can all be invoked to explain experimental results. Moreover, a simple bond‐shift rule, which is based on the change in number of trans CC double bonds (Δtrans), was developed that predicts the topology of the transition state(s) necessary to effect the desired cis‐trans isomerization. The bond‐shift rule was also applied to configuration change in dehydro[12]annulene. Finally, extensive investigation of the [14]annulene hypersurface revealed that numerous Möbius minima exist within 10 kcal/mol of the global minimum. Copyright © 2012 John Wiley & Sons, Ltd.

show abstract

Dehydro[12]annulenes: Structures, Energetics, and Dynamic Processes

Januar¹,

Huynh²,

Wood³

et al. 2010

J. Org. Chem.

View full text Add to dashboard Cite

Density functional and coupled cluster calculations on neutral monodehydro[12]annulenes (C(12)H(10)) reveal a global minimum that should be kinetically stable. At the CCSD(T)/cc-pVDZ//BHLYP/6-31G* level, the unsymmetrical CTCTC conformer 1a lies at least 3 kcal/mol below all other isomers studied. The two isomers closest in energy to 1a are Möbius structure 5a (CCTCC) and all-cis 6a. Isomer 1a can undergo conformational automerization with E(a) = 3.9 kcal/mol, implying that this process would be rapid on the NMR time scale, and computed (1)H NMR parameters (GIAO-B3LYP/6-311+G**//RHF/6-31G*) are presented. Cumulenic dehydro[12]annulene isomers, with 1,2,3-butatriene subunits, were found to be reactive intermediates in the interconversion of different configurations of the alkyne forms. Pathways for configuration change of 1a, and for subsequent rearrangement to biphenyl, were investigated. The 28 kcal/mol overall barrier for the lowest energy pathway connecting 1a to biphenyl suggests that 1a is kinetically stable with respect to valence isomerization.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

[12]Annulynes from 1,5‐Hexadiyne and Potassium tert‐Butoxide? Franz Sondheimer’s Hexadienynes!

Cited by 4 publications

References 9 publications

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

Mechanisms and Möbius strips: understanding dynamic processes in annulenes

Dehydro[12]annulenes: Structures, Energetics, and Dynamic Processes

Contact Info

Product

Resources

About

[12]Annulynes from 1,5‐Hexadiyne and Potassium tert‐Butoxide? Franz Sondheimer’s Hexadienynes!

Cited by 4 publications

References 9 publications

A Novel Synthesis of 2,3‐Dihydro‐1,3‐­methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

A Novel Synthesis of 2,3‐Dihydro‐1,3‐­methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

Mechanisms and Möbius strips: understanding dynamic processes in annulenes

Dehydro[12]annulenes: Structures, Energetics, and Dynamic Processes

Contact Info

Product

Resources

About

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra

A Novel Synthesis of 2,3‐Dihydro‐1,3‐methano‐1H‐indene {(Bicyclo[2.1.1]hexeno)benzene} and Analysis of Its NMR Spectra