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 <i>N</i>-Nitroso Aldol Reaction of γ,δ-Unsaturated δ-Lactones
作者:Akira Yanagisawa、Takeo Fujinami、Yu Oyokawa、Takuya Sugita、Kazuhiro Yoshida
DOI:10.1021/ol300146k
日期:2012.5.18
A catalytic asymmetric N-nitroso aldol reaction of gamma,delta-didehydro-delta-lactones with nitrosoarenes was achieved using chiral tin dibromide as the chiral precatalyst and sodium ethoxide as the base precatalyst in the presence of ethanol. Optically active alpha-hydroxyamino ketones with up to 99% ee were regioselectively obtained in moderate to high yields from various delta-aryl-substituted gamma,delta-didehydro-delta-valerolactones and o-substituted nitrosoarenes.
Selectivity of attack in nucleophilic alkylation of nitroarenes with Grignard reagents. Reactivity of some substituted nitrobenzenes and nitronaphthalenes
作者:Giuseppe Bartoli、Marcella Bosco、Alfonso Melandri、Andrea C. Boicelli