achieved using a DTBM-SEGPHOS·AgOTf complex as the chiral precatalyst and KHMDS as the base precatalyst in the presence of methanol. Optically active α-hydroxyamino ketones with up to 89% ee were regioselectively obtained in moderate to high yields not only from acyclic alkenyl esters but also from cyclic ones through the in situ generated chiral silver enolates.
在甲醇存在下,以DTBM-SEGPHOS·AgOTf配合物为手性预催化剂,KHMDS为碱预催化剂,实现了三氟乙酸烯基与亚硝基芳烃的催化不对称N-亚硝基羟醛反应。具有高达 89% ee 的光学活性 α-羟基氨基酮不仅可以从无环烯基酯中区域选择性地获得,而且还可以通过原位产生的手性银烯醇化物从环状烯基酯中区域选择性地获得。
Catalytic Enantioselective Protonation of Enol Trifluoroacetates by Means of Hydrogenocarbonates and Cinchona Alkaloids
Herein is disclosed an efficient catalyticenantioselective protonation of enol acetates by means of a readily implementable transition-metal-free chemical process. By making use of simple hygrogenocarbonates as the proton source and hydroquinine anthraquinone-1,4-diyl diether as the chiral proton shuttle, a series of cyclic enol trifluoroacetates are protonated under mild conditions to yield the corresponding