Transition metal-catalyzed C-C bond formation and reduction using carbene precursors = 전이금속 촉매와 카벤 전구체를 이용한 탄소-탄소 결합 형성반응과 환원반응에 관한 연구

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1. Rhodium-Catalyzed C-8 Alkylation and Alkynylation of Quinoline N-Oxides via C-H Bond Activation Quinolines and their derivatives are an important class of N-heterocyclic compounds widely utilized in medicinal and materials chemistry. As a result, the derivatization of quinolines has received considerable attention in synthetic chemistry. We report herein a direct introduction of alkyl and alkynyl groups at the C-8 position of quinoline N-oxide, in which the N-oxide is an effective directing group. Under the optimized rhodium-catalyzed conditions, C-8 alkylation products are obtained using highly stabilized diazo compounds and C-8 alkynylation is achieved with the alkynylated hypervalent iodine reagent. The reaction is generally conducted at room temperature and proceeds efficiently with excellent regioselectivity. In addition, zinc-mediated deoxygenation of the N-oxide products takes place leading to the corresponding quinoline derivatives under mild conditions. 2. Catalytic Deoxygenation of N-Oxides via Oxygen Atom Transfer from N-Oxides to Copper-Carbenoids A new catalytic procedure of deoxygenation of various types of N-oxides including both heterocyclic and amine derivatives has been developed. With use of diazo compounds as the oxygen acceptor, the reaction proceeds by the catalytic oxygen atom transfer from N-oxides to in situ generated copper-carbenoids. Deoxygenation occurs smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. In addition, the current method successfully applied to the one-pot synthesis of 8-functionalized quinoline by directly using quinoline. Therefore, this new procedure can be highly useful especially when it is combined with the direct C-H bond activation strategy for the derivatization of heterocyclic compounds using N-oxide as a directing group. 3. Rhodium-Catalyzed C-H Functionalization of Benzamides with Conjugated Ene-Yne-Ketones for the Synthesis of Heterocyclic Compounds We have developed a novel rhodium-catalyzed C-H functionalization of benzamides employing conjugated ene-yne-ketones as the coupling partner. The dual reactivity of conjugated ene-yne-ketones allowed the formation of both furyl-substituted isoindolinones through rhodium-carbene migratory insertion followed by C-N bond formation and tricyclic isoquinolinones through alkyne insertion followed by intramolecular cyclization. This is the first example of incorporating conjugated ene-yne-ketones into the C-H bond activation, and provides new synthetic methods for heterocyclic compounds. Further studies will focus on controlling the dual reactivity of conjugated ene-yne-ketones and demonstrating the synthetic utility of this methodology.
Advisors
Chang, Sukbokresearcher장석복researcher
Description
한국과학기술원 :화학과,
Publisher
한국과학기술원
Issue Date
2016
Identifier
325007
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 화학과, 2016.8 ,[iv, 75 p. :]

Keywords

Diazo compound; Ene-yne-ketone; Quinoline N-oxide; C-H bond activation; Reduction; 디아조 화합물; 인-아인-케톤; 퀴놀린엔옥사이드; 탄소-수소 결합 활성화; 환원반응

URI
http://hdl.handle.net/10203/222497
Link
http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=663240&flag=dissertation
Appears in Collection
CH-Theses_Ph.D.(박사논문)
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