Iridium(III)-catalyzed enantioselective Si-H bond insertion and formation of an enantioenriched silicon center.
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.
Department of Chemistry, Faculty of Science, Graduate School, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Yoichi
Y
Yasutomi
Hidehiro
H
Suematsu
Tsutomu
T
Katsuki
D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D012821:Silanes / Q000138:chemical synthesis* / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D013237:Stereoisomerism
D009942:Organometallic Compounds; D012821:Silanes; D007495:Iridium; D006859:Hydrogen; D012825:Silicon