Studies on organolithium-induced alkylative desymmetrisation of epoxides: synthesis of enantioenriched β-amino cycloheptenols from 6,7-epoxy-8-azabicyclo[3.2.1]octanes
作者:David M. Hodgson、Edyta Paruch
DOI:10.1016/j.tet.2004.04.047
日期:2004.6
The synthesis and enantioselective α-deprotonation—double ring opening of 6,7-epoxy-8-azabicyclo[3.2.1]octanes 5 using organolithiums in the presence of (−)-sparteine or (4S)-2,2′-(1-ethylpropylidene)bis-4-(1-methylethyl)-4,5-dihydrooxazole, giving amino cycloheptenols in up to 85% yield and 82% ee is described. The impact of different reaction variables on reaction profiles has been studied, including
在(-)-天冬氨酸或(4S)-2,2'-存在下,使用有机锂合成6,7-环氧-8-氮杂双环[3.2.1]辛烷5的合成和对映选择性α-去质子化描述了(1-乙基亚丙基)双-4-(1-甲基乙基)-4,5-二氢恶唑,以高达85%的收率和82%的ee给出氨基环庚烯醇。研究了不同反应变量对反应曲线的影响,包括有机锂的性质,溶剂,配体,温度和环氧化物的结构。事实证明,反应取决于所有这些变量,特别是取决于底物的结构。混合有机锂系统(Pr i Li / TMSCH 2 Li)已成功用于引入潜在的通用烯丙基硅烷官能团。