Efficient Activation of Acetals, Aldehydes, and Imines toward Silylated Nucleophiles by the Combined Use of Catalytic Amounts of [Rh(COD)Cl]<sub>2</sub>and TMS-CN under Almost Neutral Conditions
In the presence of a catalytic amount of a transition metal compound such as [Rh(COD)Cl]2, Co(acac)2, or NiCl2, trimethylsilyl cyanide smoothly reacts with acetals to form α-methoxy carbonitriles in good yields. In the coexistence of catalytic amounts of [Rh(COD)Cl]2 and TMS-CN, silyl enol ethers or ketene silyl acetals react with acetals, aldehyes, or imines to yield the corresponding coupling products in good yields under almost neutral conditions.
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
One-Pot Enol Silane Formation-Mukaiyama Aldol-Type Addition to Dimethyl Acetals Mediated by TMSOTf
作者:C. Wade Downey、Miles W. Johnson、Kathryn J. Tracy
DOI:10.1021/jo8001084
日期:2008.4.1
Various ketones, esters, amides, and thioesters add in high yield to dimethyl acetals in the presence of silyl trifluoromethanesulfonates and an amine base. Acetals derived from aryl, unsaturated, and aliphatic aldehydes are all effective substrates. The reaction proceeds in a single reaction flask, with no purification of the intermediate enolsilane necessary.
New Method for Oxidative Carbon-carbon Bond Formation by the Reaction of Allyl Ethers, 2,3-Dichloro-5,6-dicyano-<i>p</i>-benzoquinone(DDQ) and Silyl Carbon Nucleophiles
作者:Yujiro Hayashi、Teruaki Mukaiyama
DOI:10.1246/cl.1987.1811
日期:1987.9.5
Allylethers are oxidized by DDQ to generate the corresponding cationic species, which in turn react with silyl carbon nucleophiles in the presence of a catalytic amount of lithium perchlorate to afford the coupled products in a one-pot procedure in good yields.