Triflimide: An Overlooked High-Performance Catalyst of the Mukaiyama Aldol Reaction of Silyl Ketene Acetals with Ketones
作者:Han Yong Bae、Benjamin List
DOI:10.1002/chem.201803142
日期:2018.9.18
The Mukaiyamaaldolreaction is a widely applied carbon–carbon bond forming reaction. However, despite numerous well‐established methods using aldehydes as acceptors, only few examples exist with ketones. Here we report a highly practical catalytic approach to this transformation, namely, the triflimide catalyzedMukaiyamaaldolreaction of silyl ketene acetals with ketones. This method exhibits a
Lewis Base Activation of Lewis Acids: Catalytic, Enantioselective Addition of Silyl Ketene Acetals to Aldehydes
作者:Scott E. Denmark、Gregory L. Beutner、Thomas Wynn、Martin D. Eastgate
DOI:10.1021/ja047339w
日期:2005.3.1
The concept of Lewisbase activation of Lewisacids has been reduced to practice for catalysis of the aldolreaction of silyl ketene acetals and silyl dienol ethers with aldehydes. The weakly acidic species, silicon tetrachloride (SiCl4), can be activated by binding of a strongly Lewis basic chiral phosphoramide, leading to in situ formation of a chiral Lewisacid. This species has proven to be a competent
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.
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
Iminium salts generated by the oxidation of amino ketene silyl acetals underwent a facile Mannichreaction with another ketene silyl acetal to give aspartic acid derivatives in good yields. The dia...