NiCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>–Zn Promoted Deallyloxycarbonylative Directed Aldo Reaction of Allyl β-Keto Carboxylates with Aldehydes to β-Hydroxy Ketones
Regie- and chemospecific deallyloxycarbonylative aldol reaction of allyl(or -lie) α,α-disubstituted β-keto carboxylate with aldehyde was effectively promoted by Ni0 (NiCl2(PPh3)2–Zn), in which the allyloxycarbonyl group (–COOCH2CH=CH2) was replaced to 1-hydroxyalkyl group(–CH(OH)R, R = alkyl, vinyl, aryl) under mild reaction conditions.
The palladium-catalyzed directed aldol reaction of aldehydes with ketone enolates generated by the decarboxylation of allyl .beta.-keto carboxylates under neutral conditions
Catalytic enantioselective synthesis of carbocyclic and heterocyclic spiranes <i>via</i> a decarboxylative aldol cyclization
作者:Kazato Inanaga、Marco Wollenburg、Shoshana Bachman、Nicholas J. Hafeman、Brian M. Stoltz
DOI:10.1039/d0sc02366c
日期:——
The synthesis of a variety of enantioenriched 1,3-diketospiranes from the corresponding racemic allyl β-ketoesters via an interrupted asymmetricallylicalkylation is disclosed. Substrates possessing pendant aldehydes undergo decarboxylative enolate formation in the presence of a chiral Pd catalyst and subsequently participate in an enantio- and diastereoselective, intramolecular aldol reaction to