Organotin perchlorates as gentle Lewis acid catalysts in Mukaiyama reaction
作者:Jian-xie Chen、Junzo Otera
DOI:10.1016/s0040-4020(97)00995-2
日期:1997.10
aldehydes, an electron-donating group increases the reactivity of aldehyde while the reverse is true with an electron-withdrawing group. These are opposite to the reactivity order in nucleophilic addition to free carbonyls. In contrast to ketene silyl acetal, enol silyl ethers derived from ketones are not activated by organotin perchlorates. Thus, these two enol silyl ethers can be discriminated from each
Grob-Fragmentation-Enabled Approach to Clavulactone Analogues
作者:Qi Gu、Xuan Wang、Bingfeng Sun、Guoqiang Lin
DOI:10.1021/acs.orglett.9b01678
日期:2019.7.5
The novel synthetic strategy for dolabellane skeleton was realized, which allowed the synthesis of clavulactone analogues 26 and 27 in a concise and efficient manner. Salient transformations include a diastereoselective Mukaiyama aldol reaction, an intramolecular nucleophilic addition reaction, a Grobfragmentation reaction, and an efficient Mukaiyama–Michael addition reaction.
Rhenium-catalyzed reaction of carbonyl compounds with ketene silyl acetals
作者:Yutaka Nishiyama、Kenta Kaiba、Rui Umeda
DOI:10.1016/j.tetlet.2009.11.109
日期:2010.2
It was found that rhenium complex is an effective catalyst for the reaction of carbonyl compounds with ketene silyl acetals. A wide range of β-silyloxy esters is obtained by the treatment of carbonyl compounds with ketene silyl acetals in the presence of a catalytic amount of ReBr(CO)5 in moderate to good yields.
Lewis Base Activation of Lewis Acids. Addition of Silyl Ketene Acetals to Aldehydes
作者:Scott E. Denmark、Thomas Wynn、Gregory L. Beutner
DOI:10.1021/ja0282947
日期:2002.11.1
olefinic aldehydes as well as aliphatic aldehydes (albeit more slowly) with excellent enantioselectivity. The homologous tert-butyldimethylsilyl ketene acetal of tert-butyl propanoate adds with nearly exclusive anti diastereoselectivity to a similar range of aldehydes also with excellent enantioselectivity. The origin of the slower reaction rate with aliphatic aldehydes is revealed to be the formation of chlorosilyl
Rare Earth Triflate-Catalyzed Addition Reactions of Acylhydrazones with Silyl Enolates. A Facile Synthesis of Pyrazolone Derivatives
作者:Hidekazu Oyamada、Shu Kobayashi
DOI:10.1055/s-1998-1638
日期:1998.3
In the presence of a catalytic amount of a rare earth triflate, benzoylhydrazones reacted with silyl enolates to afford the corresponding β-N′-benzoylhydrazino esters in high yields. The hydrazino esters thus obtained were readily converted to pyrazolone derivatives by treatment with a base. A three-component reaction between an aldehyde, an acylhydrazine, and a silyl enolate was also performed successfully.