Loading...
2016.11.15 11:21

[Thu. 17 Nov. 2016] Prof. Seunghoon Shin/Synthetic Methods Development based on Rational Analysis of Intermediates

Atachment
Attachment '1'
?

Shortcut

PrevPrev Article

NextNext Article

+ - Up Down Comment Print
?

Shortcut

PrevPrev Article

NextNext Article

+ - Up Down Comment Print
Extra Form
Speaker Prof. Seunghoon Shin
Date Thursday 17 November 2016
Time 5:00pm
Venue #331, Asan Hall, College of Science

“Synthetic Methods Development based on 

Rational Analysis of Intermediates”

 

Proper analysis and identification of reaction intermediates in catalysis often lead to new reaction discovery. In this presentation, we describe some of our recent investigations in the gold and Brőnsted acid catalysis. Allenols are found to be transient intermediates in the gold-catalyzed Meyer-Schuster rearrangement of propargyl alcohols en route to enones. In our tandem Meyer-Schuster rearrangement and ring expansion (eq. 1),1 the allenol intermediates play key roles in the diastereo- and enantioselective ring expansion of cyclobutanols having a butyne-1,4-diol unit into cyclopentanones. A related allenol intermediate could also be utilized in the context of cross-coupling chemistry. Compared to the dual Au-photoredox cross-coupling of C(sp3)-Au intermediates,2a the corresponding cross-coupling of C(sp2)-Au species for the formation of C(sp2)- C(sp2) coupling is more challenging, due to a facile proto-demetallation of C(sp2)-Au bond. The Au(I)-Au(III) cycle enabled under the photoredox condition is fast enough to outcompete this undesired side pathway (eq. 2).2b-c This protocol is catalytic both in gold- and photocatalyst and utilizes diazoniums for the dual role of external oxidant and coupling partner. Lastly, oxygenative cross-coupling of alkynes has received tremendous growth, as it obviates the use of diazo precursors. Yet, a concrete support for the involvement of Au-carbene species is still lacking and, especially, intermolecular coupling is very rare. Using Brőnsted acid as a catalytic promotor instead of Au-complex, this transformation occurs under exceptionally mild conditions allowing couplings of diverse nucleophiles (eq. 3). In addition, a SN2’ mechanism could be supported by the formation of scalemic products when chiral N-oxides were used.

 

 

1.png

 

References

1. An, J. -H.; Yun, H.; Shin, S.; Shin, S., Adv. Synth. Catal. 2014, 356, 3749.

2. (a) Sahoo, B.; Hopkinson, M. N.; Glorius, F. J. Am. Chem. Soc. 2013, 135, 5505; (b) Patil, D. V.; Yun, H.; Shin, S. Adv. Synth. Catal. 2015, 357, 2622; (c) Um, J.; Yun, H.; Shin, S. Org. Lett. 2016,18, 484.

3. Unpublished results, Patil, D. V.; Kim, S. 

 

Prof. Seunghoon Shin

Department of Chemistry, Hanyang University, South Korea


  1. [Thu. 18 May. 2017] Student Host Colloquium : 1,1-Bisborylalkane: New Class of Organoboron Compound for the Chemo, Regio and Stereoselective Organic Transformations

    Prof. Seung Hwan Cho
    Thu. 18 May. 2017
    Read More
  2. [Thu. 11 May. 2017] Prof. Andreas Heinrich/IBS Research, Center for Quantum Nanoscience, Seoul, South Korea

    Prof. Andreas Heinrich
    Thu. 11 May. 2017
    Read More
  3. [Thu. 27 Apr. 2017] Seminar was canceled!

    -
    -
    Read More
  4. [Thu. 13 Apr. 2017] Dr. Wan Ki Bae/Photoelectronic Hybrid Research Center, Korea Institute of Science and Technology, Seoul, Korea

    Dr. Wan Ki Bae
    Thu. 13 Apr. 2017
    Read More
  5. [Thu. 6 Apr. 2017] Prof. Rong-Jie Chein/Institute of Chemistry, Academia Sinica, Nankang, Taipei, Taiwan

    Prof. Rong-Jie Chein
    Thu. 6 Apr. 2017
    Read More
  6. [Thu. 30 Mar. 2017] Prof. Jeong Ho Cho/SKKU Advanced Institute of Nanotechnology (SAINT), School of Chemical Engineering, Sungkyunkwan University, Suwon, Korea

    Prof. Jeong Ho Cho
    Thu. 30 Mar. 2017
    Read More
  7. [Thu. 23 Mar. 2017] Prof. Sangsu Bae/Department of Chemistry, Hanyang University, Seoul, South Korea

    Prof. Sangsu Bae
    Thu. 23 Mar. 2017
    Read More
  8. [Fri. 17 Mar. 2017] 9th RINS Symposium

    -
    Fri. 17 Mar. 2017
    Read More
  9. [Thu. 9 Mar. 2017] Prof. Woon Ju Song/Department of Chemistry, Seoul National University, Seoul, Korea

    Prof. Woon Ju Song
    Thu. 9 Mar. 2017
    Read More
  10. Spring semester 2017 Seminar Schedule

    -
    -
    Read More
  11. [Mon. 9 Jan. 2017] Prof. Sungwook Woo/Wyss Institute for Biologically Inspired Engineering, Harvard University, USA

    Prof. Sungwook Woo
    Mon. 9 Jan. 2017
    Read More
  12. [Wed. 28 Dec. 2016] Prof. James Y. Hamilton/Development of a Broad Range of Asymmetric C–C Bond Forming Reactions with a Versatile Iridium Catalyst

    Prof. James Y. Hamilton
    Wednesday 28 December 2016
    Read More
  13. [Thu. 1 Dec. 2016] Prof. Sang-Yong Ju/Highly Pure Carbon Nanotubes sorted by a Flavin for Thin Film Transistor Applications

    Prof. Sang-Yong Ju
    Thursday 1 December 2016
    Read More
  14. [Thu. 17 Nov. 2016] Prof. Seunghoon Shin/Synthetic Methods Development based on Rational Analysis of Intermediates

    Prof. Seunghoon Shin
    Thursday 17 November 2016
    Read More
  15. [Thu. 3 Nov. 2016] Prof. Min-Sik Kim/Mass spectrometry and its applications to Biological Discovery

    Prof. Min-Sik Kim
    Thursday 3 November 2016
    Read More
  16. [Thu. 20 Oct. 2016] Prof. Chan Hyuk Kim/Novel Small Molecule-based Approaches for Cancer Immunotherapy

    Prof. Chan Hyuk Kim
    Thursday 20 October 2016
    Read More
  17. [Mon. 13 Oct. 2016] Prof. Amir H. Hoveyda/Multicomponent Catalytic Synthesis of Organoboron Compounds for Scalable Natural Product Synthesis

    Prof. Amir H. Hoveyda
    Monday 13 October 2016
    Read More
  18. [Thu. 6 Oct. 2016] Prof. Young S. Park/Atomistic Molecular Engineering of Polycyclic Aromatic Hydrocarbons

    Prof. Young S. Park
    Thursday 6 October 2016
    Read More
  19. [Thu. 29 Sep. 2016] Prof. Tae-Young Yoon/Observation of Single Membrane Proteins under Mechanical Tension

    Prof. Tae-Young Yoon
    Thursday 29 September 2016
    Read More
  20. [Thu. 22 Sep. 2016] Prof. Anna Lee/Organocatalyzed Asymmetric Reactions

    Prof. Anna Lee
    Thursday 22 September 2016
    Read More
Board Pagination ‹ Prev 1 2 3 4 5 6 7 8 Next ›
/ 8

Designed by sketchbooks.co.kr / sketchbook5 board skin

나눔글꼴 설치 안내


이 PC에는 나눔글꼴이 설치되어 있지 않습니다.

이 사이트를 나눔글꼴로 보기 위해서는
나눔글꼴을 설치해야 합니다.

설치 Cancel

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5

Sketchbook5, 스케치북5

Department of Chemistry, Korea University, Tel) +82-2-3290-3120
145 Anam-ro Seongbuk-gu Seoul, 02841, Republic of Korea
Copyright(c) 2014 KOREA UNIVERSITY DEPARTMENT of CHEMISTRY. All right reserved.