Department of Chemistry, Faculty of Science, Graduate School, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
J Am Chem Soc. 2010 Apr 7;132(13):4510-1. doi: 10.1021/ja100833h.
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 for the first time by the Si-H insertion into prochiral silanes: the reactions between prochiral silanes and tert-butyl alpha-diazopropionate in the presence of complex 5 {(aR,S), Ar = Ph} proceeded with high stereoselectivity (84-99% de, 94-->99% ee). The Si-H insertion into trisubstitued silanes with alpha-aryl-alpha-diazoacetates proceeded with almost complete enantioselectivity (>or=99% ee) by using complex 1 {(aR,R), Ar = Ph} as catalyst.
铱(III)-salen 配合物被发现能够有效地催化手性卡宾 Si-H 键插入反应。使用具有凹面 salen 配体的铱配合物 4（{(aR，S），Ar = 4-TBDPSC（6）H（4）}）作为催化剂，首次实现了高对映选择性的 Si-H 插入反应，得到了 α-烷基-α-重氮乙酸酯（> or = 97%ee）。首次通过 Si-H 插入到前手性硅烷中形成了手性硅中心：在手性硅烷与叔丁基 α-重氮丙二酸酯的反应中，在配合物 5 的存在下，反应具有高的立体选择性（84-99%de，94-> 99%ee）。使用配合物 1（{(aR，R），Ar = Ph}）作为催化剂，α-芳基-α-重氮乙酸酯与三取代硅烷的 Si-H 插入反应具有几乎完全的对映选择性（> or = 99%ee）。
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