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  • 09월 10일 16시 이후 : 초록수정 불가능, 일정확인 및 검색만 가능

제124회 대한화학회 학술발표회, 총회 및 기기전시회 안내 1,1-Difunctionalization of Unactivated Alkenes through Cationic Palladium Catalysis

2019년 9월 9일 13시 13분 08초
ORGN.P-453 이곳을 클릭하시면 발표코드에 대한 설명을 보실 수 있습니다.
10월 18일 (금요일) 11:00~12:30
Organic Chemistry
저자 및
Jinwon Jeon, Sungwoo Hong*
Department of Chemistry, Korea Advanced Institute of Science and Technology, Korea

1,2-Difunctionalization of alkenes has been intensively developed utilizing alkene polarization by π-Lewis acid activation of transition metals. In opposition to outstanding advances in 1,2-vicinal difunctionalization, a similar example for 1,1-geminal difunctionalization of unactivated alkenes, while highly appealing, remains elusive. Herein, we describe a palladium(II)-catalyzed 1,1-difunctionalization of unactivated terminal and internal alkenes using cationic palladium(II) catalysis. After initial addition of a nucleophile to the alkene, the in situ generated stable palladacycle intermediate can be broken by a cationic palladium(II) catalyst to facilitate regioselective β-hydride elimination. Site-selective oxidative 1,1-difunctionalization is achieved with two nucleophilic components, even with challenging internal cyclic and acyclic alkene substrates. Various electron-rich arene nucleophiles, such as indoles and anilines, add to alkene moiety of 3-, or 4-alkenamides to give γ,γ- or δ,δ-di-functionalized products in fully intermolecular systems. Furthermore, employing intramolecular hydroxyl, carboxyl nucleophiles with external carbon nucleophiles, this method is further extended to unsymmetric difunctionalization, offering a powerful platform for making (oxo) quaternary carbon centers. Detailed computational results point to a reaction mechanism in which the cationic palladium(II) catalysis plays an important role in facilitating the key β-H elimination and migratory insertion steps.