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Patrick Robichaux Tang Group University of Wisconsin-Madison Department of Chemistry Literature Seminar 04/28/2011

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A Recent Inquiry into the Preparation and Practical Application of Benzyne. Patrick Robichaux Tang Group University of Wisconsin-Madison Department of Chemistry Literature Seminar 04/28/2011. Overview. History. Preparation. Regioselectivity. Application. Overview. History.

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Presentation Transcript
slide1

A Recent Inquiry

into the Preparation and Practical Application of Benzyne

Patrick Robichaux

Tang Group

University of Wisconsin-Madison

Department of ChemistryLiterature Seminar

04/28/2011

overview
Overview

History

Preparation

Regioselectivity

Application

overview3
Overview

History

Preparation

Regioselectivity

Application

evidence for benzyne
Evidence for Benzyne

Roberts, J. D.; Simmons, H. E.; Carlsmith, L. A.; Vaughan, C. W. J. Am. Chem. Soc.1953,75, 3290.

neutral benzyne intermediate
Neutral Benzyne Intermediate?

Roberts, J. D.; Simmons, H. E.; Carlsmith, L. A.; Vaughan, C. W. J. Am. Chem. Soc. 1953,75, 3290.

singlet or triplet
Singlet or Triplet?
  • hν = diradical?
  • Benzyne actually singlet
  • singlet-triplet splitting of 37.5 kcal/mol
  • lifetime at least 20 ms

Wittig, G.; Ebel, H. F. Angew. Chem.1960,72, 564.

Wentrup, C. Aust. J. Chem.2010,63, 979.

overview7
Overview

History

Preparation

Regioselectivity

Application

traditional formation of benzyne
Traditional Formation of Benzyne

Kitamura, T. Aust. J. Chem.2010,63, 987.

Wentrup, C. Aust. J. Chem.2010,63, 979.

Pellissier, H.; Santelli, M. Tetrahedron2003,59, 701.

synthesis of silyltriflate
Synthesis of Silyltriflate

Bronner, S. M.; Garg, N. K. J. Org. Chem.2009, 74, 8842-8843.

Tadross, P. M.; Gilmore, C. D.; Bugga, P.; Virgil, S. C.; Stoltz, B. M. Org. Lett.2010, 12, 1224-1227.

Wu, Q.-c.; Li, B.-s.; Shi, C.-q.; Chen, Y.-x. HechengHuaxue2007, 111.

Himeshima, Y.; Sonada, T.; Kobayashi, H. Chem. Lett.1983, 1211.

  • Peña, D.; Cobas, A.; Pérez, D.; Guitián, E. Synthesis2002. 1454.
activation domino
Activation Domino
  • Silyl protecting group tolerant

Ikawa, T.; Nishiyama, T.; Nosaki, T.; Takagi, A.; Akai, S. Org. Lett.2011, 13, 1730.

new method c h activation
New Method: C-H activation

CHEAP!

  • highly solvent and concentration dependent
  • Optimized conditions: Pd(OAc)2 (10 mol %)
  • Cu(OAc)2 (0.75 equiv.)
  • 1,10-phenanthroline (10 mol %)
  • K2HPO4 (2 equiv.) , TBAB (1 equiv.)
  • sulfonane, 4 Å MS

<47% yield

+ side products

Cant, A. A.; Roberts, L.; Greaney, M. F. Chemical Communications2010, 46, 8671-8673.

overview12
Overview

History

Preparation

Regioselectivity

Application

regioselectivity sterics
Regioselectivity: Sterics

Diemer, V.; Begaud, M.; Leroux, F. R.; Colobert, F. Eur. J. Org. Chem.2011, 341.

regioselectivity sterics vs electronics
Regioselectivity: Sterics vs. Electronics

Diemer, V.; Begaud, M.; Leroux, F. R.; Colobert, F. Eur. J. Org. Chem.2011, 341.

regioselectivity electronics
Regioselectivity: Electronics

Diemer, V.; Begaud, M.; Leroux, F. R.; Colobert, F. Eur. J. Org. Chem.2011, 341.

distortion interaction model
Distortion/Interaction Model

Cheong, P. H. Y.; Paton, R. S.; Bronner, S. M.; Im, G. Y. J.; Garg, N. K.; Houk, K. N. J. Am. Chem. Soc. 2010,132, 1267.

Im, G. Y. J.; Bronner, S. M.; Goetz, A. E.; Paton, R. S.; Cheong, P. H. Y.; Houk, K. N.; Garg, N. K. J. Am. Chem. Soc. 2010, 132, 17933.

reactivity of indolyne systems
Reactivity of Indolyne Systems

Im, G. Y. J.; Bronner, S. M.; Goetz, A. E.; Paton, R. S.; Cheong, P. H. Y.; Houk, K. N.; Garg, N. K. J. Am. Chem. Soc. 2010, 132, 17933.

overview18
Overview

History

Preparation

Regioselectivity

Application

acyl alkylation of arynes
Acyl-Alkylation of Arynes

Tambar, U. K.; Stoltz, B. M. J. Am. Chem. Soc. 2005,127, 5340.

acyl alkylation of arynes21
Acyl-Alkylation of Arynes

Tambar, U. K.; Ebner, D. C.; Stoltz, B. M. J. Am. Chem. Soc. 2006,128, 11752.

indolines and isoquinolines
Indolines and Isoquinolines

Gilmore, C. D.; Allan, K. M.; Stoltz, B. M. J. Am. Chem. Soc. 2008,130, 1558.

indolyne regioselectivity reversal
Indolyne: Regioselectivity Reversal

Bronner, S. M.; Goetz, A. E.; Garg, N. K. J. Am. Chem. Soc. 2011,133, 3832.

indole synthesis
Indole Synthesis

Barluenga, J.; Fananas, F. J.; Sanz, R.; Fernandez, Y. Chemistry-a European Journal2002,8, 2034.

biaryl synthesis
Biaryl Synthesis

Milne, J. E.; Buchwald, S. L. J. Am. Chem. Soc. 2004,126, 13028.

enamide cascade
Enamide Cascade

Feltenberger, J. B.; Hayashi, R.; Tang, Y.; Babiash, E. S. C.; Hsung, R. P. Org. Lett.2009,11, 3666.

4 2 cycloaddition on arene system
[4+2] Cycloaddition on Arene System

Nishimura, T.; Nagaosa, M.; Hayashi, T. Chem.Lett.2008,37, 860.

metal free click chemistry
Metal Free Click Chemistry

Lin, Y.; Chen, Y.; Ma, X.; Xu, D.; Cao, W.; Chen, J. Tetrahedron2011,67, 856.

slide30

Indole Synthesis

  • Nair, V.; Kim, K. H. J. Org. Chem.1975,40, 3784.
3 component benzyne coupling
3-Component Benzyne Coupling

Larrosa, I.; Da Silva, M. I.; Gómez, P. M.; Hannen, P.; Ko, E.; Lenger, S. R.; Linke, S. R.; White, A. J. P.; Wilton, D.; Barrett, A. G. M. J. Am. Chem. Soc. 2006,128, 14042.

3 component benzyne coupling33
3-Component Benzyne Coupling

Larrosa, I.; Da Silva, M. I.; Gómez, P. M.; Hannen, P.; Ko, E.; Lenger, S. R.; Linke, S. R.; White, A. J. P.; Wilton, D.; Barrett, A. G. M. J. Am. Chem. Soc. 2006,128, 14042.

catalytic carbonylation
Catalytic Carbonylation

Chatani, N.; Kamitani, A.; Oshita, M.; Fukumoto, Y.; Murai, S. J. Am. Chem. Soc. 2001,123, 12686.

pd catalyzed
Pd-catalyzed

Heck:

Suzuki:

Jayanth, T. T.; Jeganmohan, M.; Cheng, C.-H. Org. Lett.2005,7, 2921.

Henderson, J. L.; Edwards, A. S.; Greaney, M. F. Org. Lett.2007,9, 5589.

conclusions
Conclusions

=

Image from google images

acknowledgments
Acknowledgments
  • Professor Weiping Tang
  • Tang and Hsung group
  • Kat Myhre
  • Practice Talk Attendees:
    • Jenny B. Werness
    • Dongxu Shu
    • Wei Zhang
    • Renhe Liu
    • Xiaoxun Li
    • Dr. Xingzhong Shu
    • Suyu Huang
    • Andrew G. Lohse
    • Kyle Dekorver