Direct asymmetric aminoxylation reaction catalyzed by a binaphthyl-based chiral amino sulfonamide with high catalytic performance
作者:Taichi Kano、Akihiro Yamamoto、Keiji Maruoka
DOI:10.1016/j.tetlet.2008.06.093
日期:2008.9
A binaphthyl-based aminosulfonamide (S)-2 was applied to the direct asymmetric aminoxylation of aldehydes with nitrosobenzene. The reactioncatalyzed by (S)-2 proceeded smoothly to give the aminoxylated product in good yield with excellent enantioselectivity. This method represents a rare example of the highly enantioselective aminoxylation by a non-proline type catalyst with high catalytic performance
p‐nitrobenzoic acid, the O‐nitroso aldol reaction of nitrosobenzene with enolisable aldehydes may be promoted by commercially available α,α‐diphenylprolinol trimethylsilylether. The reaction proceeds with good yields and essentially complete enantioselectivity, with catalyst loadings in the 5–10 mol % range. The resulting α‐oxyaldehyde adducts may be transformed in situ into α‐oxyimines, which provide 1,2‐amino
Binaphthyl-based amino acids (S)-1 and an aminosulfonamide (S)-2 were applied for directasymmetricaminoxylation with nitrosobenzene. In the presence of either (S)-1 or (S)-2, the aminoxylation of aldehydes proceeded smoothly, and subsequent reduction with NaBH4 gave 2-aminoxyl alcohols with good to excellent enantioselectivities. In each case, binaphthyl-basedchiralamine catalysts (S)-1 and (S)-2