73110-73-3

Upstream product

• 766-96-1 4-bromo-1-ethynylbenzene 
• 635-93-8 5-chlorosalicyclaldehyde 
• 1450-74-4 5-chloro-2-hydroxyacetophenone 
• 1122-91-4 4-bromo-benzaldehyde 
• 1309972-83-5 3-(4-bromophenyl)-1-(5-chloro-2-hydroxyphenyl)-3-hydroxypropan-1-one 

Relevant academic research and scientific papers

Organocatalytic Approach for Assembling Flavanones via a Cascade 1,4-Conjugate Addition/oxa-Michael Addition between Propargylamines with Water

A DBU-catalyzed one-pot cascade reaction of propargylamines and water for the synthesis of flavanones has been developed. This process proceeds via a sequence of 1,4-conjugate addition of water to alkynyl o-quinone methide (o-AQM), followed by the alkyne-allene isomerization and subsequent intramolecular oxa-Michael addition. This strategy provides a convenient method for accessing a broad range of flavanones in good to excellent yields with good functional-group tolerance, in particular, the reactive halo functional groups.

Environmentally benign syntheses of flavanones

Mild and environmentally benign methods for the syntheses of flavanones are described. The reaction of o-hydroxyacetophenones (1) and benzaldehydes (2) in water in the presence of DABCO at room temperature gave 3-hydroxy-1-(2- hydroxylphenyl)-3-arylpropan-1-ones (3a-i) as intermediates. Followed by an intramolecular dehydration of the 3a-i with the modified Mitsunobu's reaction, the target flavanones (4a-i) were obtained. Moreover, the reaction of 1 and 2 at the same conditions but at reflux gave flavanones in one pot with good yields.