Chemoselective Aldol Reaction of Silyl Enolates Catalyzed by MgI<sub>2</sub> Etherate
作者:Wei-Dong Z. Li、Xing-Xian Zhang
DOI:10.1021/ol026585e
日期:2002.10.1
Mukaiyama-type aldol coupling of typical silyl enolates 2-4 with aryl or vinyl aldehydes and acetals was realized in the presence of 1-5 mol % of MgI(2) etherate (1) in a mild, efficient, and highly chemoselective manner. Iodide counterion, weakly coordinating peripheral ethereal ligands (Et(2)O) of Mg(II), and a noncoordinating reactionmedia (i.e. CH(2)Cl(2)) are among the critical factors for the
are performed simultaneously on separate reaction sites, has been advanced. Ketones/α,β-enones and aldehydes/acetals are able to react selectively with different silyl nucleophiles in parallel. The subtle differentiation between the substrates possessing similar reactivities has recourse to the strong preference of ketene silyl acetal for ketones/α,β-enones.
SATO, TSUNEO;OTERA, JUNZO;NOZAKI, HITOSI, J. AMER. CHEM. SOC., 112,(1990) N, C. 901-902
作者:SATO, TSUNEO、OTERA, JUNZO、NOZAKI, HITOSI
DOI:——
日期:——
FeCl<sub>3</sub>·6H<sub>2</sub>O-Catalyzed Mukaiyama-Aldol Type Reactions of Enolizable Aldehydes and Acetals
作者:Alejandra Rodríguez-Gimeno、Ana B. Cuenca、Jesús Gil-Tomás、Mercedes Medio-Simón、Andrea Olmos、Gregorio Asensio
DOI:10.1021/jo501498a
日期:2014.9.5
stable catalyst, lead to β-methoxycarbonyl compounds with nearly quantitative yields. The methodology is extended to the parent aldehydes as starting materials, leading to the corresponding aldols with lower yields, but efficiently. Different alkyl and aryl substituted acetals and aldehydes have been tested in the reaction with linear and cyclic silyl enolethers. Reactions are carried out in an open air