Iridium(III)-Catalyzed Enantioselective Si−H Bond Insertion and Formation of an Enantioenriched Silicon Center
作者:Yoichi Yasutomi、Hidehiro Suematsu、Tsutomu Katsuki
DOI:10.1021/ja100833h
日期:2010.4.7
Iridium(III)-salen complexes were found to efficiently catalyze enantioselective carbene Si-H bond insertion. Highly enantioselective Si-H insertion with alpha-alkyl-alpha-diazoacetates (>or=97% ee) was achieved for the first time by using the iridium complex 4 (aR,S), Ar = 4-TBDPSC(6)H(4)} bearing a concave-shaped salen ligand as the catalyst. Formation of a chiral silicon center was also achieved
发现铱 (III)-salen 配合物可有效催化对映选择性卡宾 Si-H 键插入。通过使用铱络合物 4 (aR,S), Ar = 4-TBDPSC(6)H,首次实现了具有 α-烷基-α-重氮乙酸盐 (>or=97% ee) 的高对映选择性 Si-H 插入(4)}带有凹形Salen配体作为催化剂。通过将 Si-H 插入前手性硅烷中,也首次实现了手性硅中心的形成:在配合物 5 存在下,前手性硅烷与 α-重氮丙酸叔丁酯之间的反应 (aR,S), Ar = Ph} 具有高立体选择性(84-99% de,94-->99% ee)。通过使用配合物 1 (aR,R), Ar = Ph} 作为催化剂,Si-H 插入具有 α-芳基-α-重氮乙酸酯的三取代硅烷中几乎完全对映选择性(> 或 = 99% ee)。