Palladium-Catalyzed Tandem Heck/Regiodivergent C(sp3)-H Activation for Selective Construction of Spiro and Fused Cyclopropanated Indolines
- 발행기관 서강대학교 일반대학원
- 지도교수 이원구
- 발행년도 2016
- 학위수여년월 2016. 8
- 학위명 석사
- 학과 및 전공 일반대학원 화학과
- 실제URI http://www.dcollection.net/handler/sogang/000000059961
- 본문언어 영어
- 저작권 서강대학교 논문은 저작권보호를 받습니다.
초록/요약
A novel palladium-catalyzed tandem Heck/regiodivergent C(sp3)-H bond activation giving selectively spiro and fused cyclopropanated indolines from a common N-allylated 2-bromoanilines has been developed. The σ-alkylpalladium(II) intermediate A, formed by 5-exo-trig Heck carbopalladation, could activate the exo-alkyl C(sp3)-H bond to give spiro-cyclopropanated indulines in a polar DMSO solvent. In comparison, the endo-alkyl C(sp3)-H bond could be activated selectively to give fused-cyclopropanated indoline moiety in a non-polar p-xylene solvent. Kinetic isotope effect experiments indicated that the cleavage of C-H bonds is turnover limiting step in both catalytic reactions. And the reductive and alkynylative trapped indolines were confirmed with ammonium formate and phenyl acetylene additive as each sole products in almost quantitative yield. The reactions were successful with electron-neutral, electron-donating and electron-deficient groups on the aromatic ring.
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