109311-90-2Relevant articles and documents
Synthesis of dihydropyranones and dihydropyrano[2,3-d][1,3]dioxine-diones by cyclization reaction of Meldrum's acid with arylaldehydes and 1,3-dicarbonyls under thermal and ultrasound irradiation
Mehrabi, Hossein,Najafian-Ashrafi, Faezeh,Ranjbar-Karimi, Reza
, p. 191 - 199 (2018)
The present paper deals with the synthesis of novel dihydropyranone and dihydropyrano[2,3-d][1,3]dioxinedione derivatives via one-pot three-component reaction between Meldrum's acid, arylaldehydes, and various 1,3-dicarbonyls in the presence of KOH as a base in H2O:EtOH under thermal and ultrasound irradiation. It was observed that ultrasound-Assisted method gave 80-94% yields in 30-45 min as against 120-280 min required to get 60-82% yields by thermal method. Formula parented.
Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: Oxidative NHC catalysis via multistep electron transfer
Ta,Axelsson,Sundén
supporting information, p. 686 - 690 (2016/02/12)
To replace high molecular weight oxidants with air (O2) we introduce multistep electron transfer NHC catalysis. The method provides a general and selective oxidation of the α,β-unsaturated aldehyde derived homoenolate to the synthetically useful α,β-unsaturated acyl azolium intermediate. Several independent oxidative NHC-catalyzed reactions are viable with this strategy and the products can be isolated in high to excellent yields.
Direct β-activation of saturated aldehydes to formal michael acceptors through oxidative NHC catalysis
Mo, Junming,Shen, Liang,Chi, Yonggui Robin
supporting information, p. 8588 - 8591 (2013/09/12)
Without detours: Oxidative catalysis mediated by N-heterocyclic carbenes (NHCs) enables the direct β-carbon functionalization of saturated aldehydes (see scheme). The reaction proceeds through two sequential oxidative steps to generate α,β-unsaturated tri
