Catalytic asymmetric synthesis of 2,2-disubstituted terminal epoxides via dimethyloxosulfonium methylide addition to ketones.
Catalytic asymmetric Corey-Chaykovsky epoxidation of ketones with dimethyloxosulfonium methylide 2 using an LLB 1a + Ar3P O complex proceeded smoothly at room temperature, and 2,2-disubstituted terminal epoxides were obtained in high enantioselectivity (91-97%) and yield (>88-99%) from a broad range of methyl ketones with 1-5 mol % catalyst loading. The use of achiral additive Ar3P O 5i was important to achieve high enantioselectivity.
Sone
Toshihiko
T
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yamaguchi
Akitake
A
Matsunaga
Shigeki
S
Shibasaki
Masakatsu
M
D002384:Catalysis; D004852:Epoxy Compounds / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry*; D009943:Organophosphorus Compounds; D013452:Sulfonium Compounds / Q000737:chemistry*
D004852:Epoxy Compounds; D007659:Ketones; D009943:Organophosphorus Compounds; D013452:Sulfonium Compounds; C525609:dimethyloxosulfonium methylide