62282-32-0Relevant academic research and scientific papers
Non-metal Lewis acid-catalyzed cross-Claisen condensation for β-keto esters
Han, Zhengyu,Huang, Hai,Meng, Fuliang,Yang, Zhenkun,Zhang, Tianyu,Zhou, Dapeng
supporting information, p. 9163 - 9166 (2021/11/16)
In this work, we disclose a new catalytic and highly chemoselective cross-Claisen condensation of esters. In the presence of TBSNTf2 as a non-metal Lewis acid, various esters can undergo cross-Claisen condensation to form β-keto esters which are important building blocks. Compared with the traditional Claisen condensation, this process, employing silyl ketene acetals (SKAs) as carbonic nucleophiles to achieve cross-Claisen condensation, requires mild conditions and has good tolerance of functional groups. This journal is
Click and Release: A High-Content Bioorthogonal Prodrug with Multiple Outputs
Ji, Xingyue,Aghoghovbia, Robert E.,De La Cruz, Ladie Kimberly C.,Pan, Zhixiang,Yang, Xiaoxiao,Yu, Bingchen,Wang, Binghe
supporting information, p. 3649 - 3652 (2019/05/24)
A high-content bioorthogonal prodrug with multiple outputs using the "click, cyclize, and release" concept is described. The proof of concept is established by the co-delivery of a gasotransmitter carbon monoxide, an anticancer drug floxuridine, and an in
Oxone-promoted hydration of electron-deficient allenic esters and ketones into 1,3-dicarbonyl compounds
Yi, Yu-Ping,Zheng, Yan,Nie, Jing,Ma, Jun-An
, p. 4523 - 4526 (2015/06/30)
Abstract A novel and mild protocol for the hydration of electron-deficient allenic esters and ketones into various 1,3-dicarbonyl compounds is described. The hydration of allenes promoted by oxone in DMF afforded the corresponding products in moderate to good yields. This work features the employment of only a catalytic amount of inexpensive and nontoxic solid reagent oxone (2KHSO5·KHSO4·K2SO4), avoiding the utility of toxic metals or traditional Br?nsted acids, in a green version of viewpoint. A possible reaction mechanism for this transformation is also primarily proposed.
A stereoselective and practical synthesis of (E)-α,β-unsaturated ketones from aldehydes
Balducci, Evita,Attolino, Emanuele,Taddei, Maurizio
experimental part, p. 311 - 318 (2011/02/28)
α,β-Unsaturated ketones can be prepared by reaction of differently substituted β-keto acids and aldehydes. The reaction is carried out under organocatalysis (β-alanine, 0.5 equiv.) and generates the enones with high E selectivity (>95%). This version of the Verley-Doebner modification of the Knoevenagel reaction is a practical alternative to the classic Horner-Wadsworth-Emmons (HWE) reaction without the formation of high molecular weight byproducts. The process makes use of simple reagents and can be applied to large-scale synthesis under conditions compatible with atom-economy principles. Differently substituted aliphatic, aromatic, or heteroaromatic α,β-unsaturated ketones can be prepared. An example of a hydroformylation/Verley-Doebner Knoevenagel telescoped process is also described. The conditions used in the Knoevenagel reaction to prepare conjugated esters under amino acid organocatalysis can be applied also for the synthesis of α,β unsaturatedketones. β-Keto acids are prepared byhydrogenolysis of the corresponding benzyl ester and react easily with aldehydes to give the α,β-unsaturated ketones without formation of high molecular weight byproducts. Copyright
β-Keto esters derived from 2-(trimethylsilyl)ethanol: An orthogonal protective group for β-keto esters
Knobloch, Eva,Brueckner, Reinhard
experimental part, p. 2229 - 2246 (2009/04/08)
β-Keto esters derived from 2-(trimethylsilyl)ethanol undergo cleavage and decarboxylation when treated with 0.75 equivalents of tetrabutylammonium fluoride trihydrate in tetrahydrofuran at 50°C, while β-keto esters derived from methanol, tert-butyl alcohol, allyl alcohol, or benzyl alcohol stay intact. Conversely, methyl-, tert-butyl-, allyl-, or benzyl β-keto esters can be cleaved and decarboxylated without the 2-(trimethylsilyl)ethyl β-keto esters being affected. Similarly, mixed bis(β-keto esters) derived from 2-(trimethylsilyl)ethanol and methanol, tert-butyl alcohol, allyl alcohol, or benzyl alcohol can be defunctionalized chemoselectively under the same reaction conditions. Georg Thieme Verlag Stuttgart.
