Enantioselective Organic Syntheses Using Chiral Transition Metal Complexes, 9 Atropo-Diastereoselective Ring Opening of Biaryl Thionolactones Using [CpRu{(S,S)-CHIRAPHOS}]+ as a Chiral Auxiliary
作者:Wolfdieter A. Schenk、Jörg Kümmel、Irene Reuther、Nicolai Burzlaff、Andreas Wuzik、Olaf Schupp、Gerhard Bringmann
DOI:10.1002/(sici)1099-0682(199910)1999:10<1745::aid-ejic1745>3.0.co;2-1
日期:1999.10
crystallized as the pure (S,S,P) diastereoisomer, was determined by X-ray crystallography. Coordination of the ruthenium fragment caused an elongation of the C=S bond, a contraction of the C–O bond within the lactone ring and a flattening of that ring. Single hydride transfer with LiBEt3H converted 4a–f into the thiolactolate complexes 5a–f in good yields and diastereoselectivities. An X-ray structure determination
取代不稳定的噻吩络合物 [CpRu(S,S)-CHIRAPHOS}(SC4H4)]BF4 (2) [(S,S)-CHIRAPHOS = (2S,3S)bis(diphenylphosphanyl)butane],由 [CpRu (S,S)-CHIRAPHOS}Cl] (1)、噻吩和 AgBF4 与联芳基硫醇内酯 3a-f 反应以高产率得到相应的 S 配位配合物 4a-f。4c 的结构以纯 (S,S,P) 非对映异构体结晶,通过 X 射线晶体学确定。钌片段的配位导致 C=S 键的伸长、内酯环内 C-O 键的收缩和该环的扁平化。LiBEt3H 的单氢化物转移以良好的产率和非对映选择性将 4a-f 转化为硫代乳酸配合物 5a-f。5a 的主要异构体的 X 射线结构测定表明它是 (S,S,S,P) 非对映异构体。用 NH4PF6 质子化将 5a-f 转化为相应的开环硫醛配合物 6a-f。5a 与甲基碘的烷基化导致