6969-02-4Relevant articles and documents
Application of chiral TADDOL ligand and rare earth metal amide in combined catalysis of asymmetric reaction
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Paragraph 0148-0151, (2020/11/23)
The invention relates to application of chiral TADDOL ligand and rare earth metal amide in combined catalysis of asymmetric epoxidation reaction of chalcone compounds. According to the application, alpha, beta-unsaturated ketone shown in a formula (1) and tert-butyl hydroperoxide react in the presence of organic alkali under the combined catalytic action of a chiral TADDOL ligand shown in a formula (3) and rare earth metal amide in an anhydrous, oxygen-free and protective atmosphere to obtain the chiral epoxy compound shown in the formula (2) after the reaction is completed, wherein R1 is selected from hydrogen, alkyl, halogen, alkoxy, trifluoromethyl, nitro or cyano, R2 is selected from phenyl, substituted phenyl, naphthyl, furyl or thienyl; R3 and R4 are respectively and independently selected from alkyl, phenyl or R3 and R4 and carbon atoms connected with R3 and R4 form naphthenic base; Ar is phenyl, substituted phenyl, biphenyl or naphthyl; the molecular formula of the rare earth metal amide is RE [N (SiMe3) 2] 3. The method has the advantages of wide substrate application range, high yield and high enantioselectivity.
Facile epoxidation of α, β-unsaturated ketones with urea-2,2-dihydroperoxypropane as a new oxidant
Khosravi, Kaveh,Naserifar, Shirin
, p. 323 - 328 (2017/01/10)
Abstract: Various aromatic α, β-unsaturated ketones were successfully transformed into their corresponding epoxides using urea-2,2-dihydroperoxypropane as the oxygen source for the first time. The reactions were carried out under mild alkaline conditions at room temperature in high yields and short reaction times. Graphical Abstract: [Figure not available: see fulltext.]
A highly enantioselective asymmetric Darzens reaction catalysed by proline based efficient organocatalysts for the synthesis of di- and tri-substituted epoxides
Ashokkumar, Veeramanoharan,Siva, Ayyanar,Ramaswamy Chidambaram
supporting information, p. 10926 - 10929 (2017/10/13)
A new class of easily available and readily tunable proline based chiral organocatalysts was found to efficiently catalyse an unprecedented highly enantioselective asymmetric Darzens reaction of α-chloroketones and substituted α-chloroketones with various