86661-27-0Relevant academic research and scientific papers
Asymmetric One-Pot Mukaiyama Michael/Michael Reaction Catalyzed by Diphenylprolinol Silyl Ether
Hayashi, Yujiro,Umekubo, Nariyoshi
, p. 5596 - 5600 (2020)
The asymmetric catalytic Mukaiyama Michael reaction between α,β-unsaturated aldehydes and silyl enol ether derived from a cyclic ketone was catalyzed by diphenylprolinol silyl ether to afford Michael products with excellent diastereo- and enantioselectivities. Bicyclo[2.2.2]octanone derivatives can be synthesized as a single isomer in a nearly optically pure form via a two-step, one-pot reaction, comprising the sequential Mukaiyama Michael reaction and intramolecular Michael reaction starting from dienol silyl ether and α,β-unsaturated aldehydes, catalyzed by diphenylprolinol silyl ether. In the second Michael reaction, positive kinetic resolution occurred to increase the enantioselectivity.
Direct Asymmetric Michael Reaction of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Two Secondary Amine Catalysts
Hayashi, Yujiro,Umekubo, Nariyoshi
, p. 1958 - 1962 (2018)
A direct asymmetric Michael reaction of α,β-unsaturated aldehydes and ketones proceeded in the presence of two pyrrolidine-type catalysts, a diphenylprolinol silyl ether and hydroxyproline, to afford synthetically useful δ-keto aldehydes with excellent diastereo- and enantioselectivity. Although there are several iminium ions and enamines in the reaction mixture, the iminium ion generated by the former catalyst reacts preferentially with the enamine generated by the latter catalyst.
Nucleophilic addition of enols and enamines to α,β-unsaturated acyl azoliums: Mechanistic studies
Samanta, Ramesh C.,Maji, Biplab,De Sarkar, Suman,Bergander, Klaus,Froehlich, Roland,Mueck-Lichtenfeld, Christian,Mayr, Herbert,Studer, Armido
supporting information; experimental part, p. 5234 - 5238 (2012/07/27)
1,4 but not 1,2! The reactivity of 1 towards different nucleophiles (deprotonated β-diketones, enamines, and malonodinitrile) was investigated by NMR and kinetic experiments. These investigations proved that C-C bond formation occurs by a Michael-type 1,4-addition and not by a 1,2-addition and subsequent [3,3]-sigmatropic rearrangement. The first X-ray structure of an α,β-unsaturated acyl azolium salt (1) is also presented. Copyright
Acyclic stereocontrol in fischer carbene chemistry by syn-selective Michael addition/trapping sequence
Nakamura, Eiichi,Tanaka, Koichi,Fujimura, Tsutomu,Aoki, Satoshi,Williard, Paul G.
, p. 9015 - 9020 (2007/10/02)
Michael addition of a metal enolate to a Fischer vinyl carbene complex 1 takes place with syn-diastereoselectivity. The resulting anion 2 can be trapped stereoselectively to afford a carbene complex 3 with stereocontrol of three contiguous stereogenic cen
Asymmetric Michael Additions. Stereoselective Alkylations of the (R)- and (S)-Enamine from Cyclohexanone and 2-(Methoxymethyl)pyrrolidine by Methyl α-(Methoxycarbonyl)cinnamates
Blarer, Stefan J.,Seebach, Dieter
, p. 2250 - 2260 (2007/10/02)
Alkylation of (2S)-1-(1-cyclohexen-1-yl)-2-(methoxymethyl)pyrrolidine ((S)-1, enamine from cyclohexanone and 2-(methoxymethyl)pyrrolidine) by the Knoevenagel condensation products 4 of aromatic aldehydes yields 35-76percent of Michael adducts (1 + 4 -> ->
