Synthetic Efforts towards Chiral Phosphine Ligands for Enantioselective Reaction
- 발행기관 서강대학교 대학원
- 지도교수 강재효
- 발행년도 2010
- 학위수여년월 2010. 8
- 학위명 석사
- 학과 및 전공 일반대학원 화학과
- 실제URI http://www.dcollection.net/handler/sogang/000000046067
- 본문언어 영어
초록/요약
높은 입체장애를 가지는 비대칭 포스핀 리간드는 거울상 이성질체 선택적 반응에서 효율성을 높여준다. 비대칭 촉매반응에 유용한 구조적 특징을 가진 2-(di-tert-butylphosphino)-1-(2,4,6-triisopropylphenyl)-1H-pyrrole, di-tert-butyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicyclo[2.2.1]hept-2-en-2-yl)phosphine, 그리고 diadamantyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicyclo[2.2.1]hept-2-en-2-yl)phosphine의 합성을 시도하였다. 이 과정에서 2-(diisopropylphosphino)-1-(2,4,6-triisopropylphenyl)-1H-pyrrole을 11%의 수득률로 얻을 수 있었고, di-tert-butyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicycle [2.2.1]hept-2-en-2-yl)phosphine과 diadamantyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicyclo[2.2.1]hept-2-en-2-yl)phosphine 합성의 중간체인 (1S,4S)-3-bromo-1,7,7-trimethylbicyclo[2.2.1]hept-2-en-2-yl trifluoromethanesulfonate를 96%의 높은 수득률로 합성하였다.
more초록/요약
Highly congested chiral phosphine ligands exhibit high efficiency in enantioselective reactions. Attempts for synthesizing 2-(di-tert-butylphosphino)-1-(2,4,6-triisopropylphenyl)-1H-pyrrole, di-tert-butyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicycle[2.2.1]hept-2-en-2-yl)phosphine, and diadamantyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicycle[2.2.1]hept-2-en-2-yl)phosphine, which have structural attribute that is conducive to asymmetric catalytic reactions, was conducted. 2-bromo-1-(2,4,6-triisopropylphenyl)pyrrole was transformed to N-(2,4,6-triisopropyl)-2-lithiopyrrole via lithium-halogen exchange with n-butyl lithium, and the resulting lithiopyrrole was subsequently quenched with the corresponding diisopropyl chlorophosphine to give 2-(diisopropylphosphino)-1-(2,4,6-triisopropylphenyl)-1H-pyrrole in poor yield (11%). (1S,4S)-3-bromo-1,7,7-trimethylbicyclo[2.2.1]hept-2-en-2-yl trifluoromethanesulfonate, which was intermediate of di-tert-butyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicyclo[2.2.1]hept-2-en-2-yl)phosphine and diadamantyl((1S,4S)-4,7,7-trimethyl-3-(2,4,6-triisopropylphenyl)bicyclo[2.2.1]hept-2-en-2-yl)phosphine, was successfully synthesized in good yield (96%).
more