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Type |
Oral Presentation |
Area |
Oral Presentations for Young Scholars in Organic Division |
Room No. |
Room 325A+B |
Time |
THU 09:45-: |
Code |
ORGN.O-4 |
Subject |
Synthesis of Chiral [1,4]-diazocines : Enantioselective Rhodium(II)-catalyzed [5+3] Cycloaddition |
Authors |
Ju Young Lee, Eun Jeong Yoo* Department of Applied Chemistry, Kyung Hee University, Korea |
Abstract |
Eight-membered heterocycles are one of the most significant classes of compounds as it has been found in as key structural motif in a large number of biologically important natural products and pharmaceuticals. Among the established approaches including most popular ring-closing metathesis, Heck or other cross-coupling reactions for the synthesis of such medium-ring heterocycles the higher-order cycloaddition strategy is believed to be hard as it associated with unfavourable enthalpic and entropic parameters. As a consequence, the number of reports describing [5+3] cycloaddition to form eight-membered heterocycles are limited.
Recently, our group disclosed a novel intermolecular rhodium(II)-catalyzed [5+3] cycloaddition between pyridinium zwitterions as 1,5-dipole equivalents and enol diazoacetates for the efficient formation of eight-membered heterocycles. Also, we have investigated the detail mechanistic insight of this reaction based on DFT study. Based on our previous results, we developed the asymmetric version of this interesting methodology using a chiral Rh(II)-catalyst and tuning the reaction condition. Despite this initial success, we were unable to apply this protocol as general basis. After extensive screening of the reaction conditions, we envisioned that some structural tuning is required for both the zwitterionic species and the diazo-substrate. In this symposium we will discuss our successful approach towards asymmetric [5+3]-cycloaddition between quinoline-based 1,5-dipole with vinyl diazoacetate partners.
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E-mail |
ljy850706@naver.com |
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