147919-55-9Relevant articles and documents
Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: A highly enantioselective pathway for accessing chiral flavanones
He, Qijie,Wang, Jun,So, Chau Ming,Hayashi, Tamio,Bian, Zhaoxiang
supporting information, p. 540 - 543 (2015/05/05)
Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addi-tion of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod, the 1,4-addition of a variety of aryl-boronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions.
Solution phase photocyclisation reaction of 2-hydroxychalcones to 4-flavanones
Kamboj, Ramesh C.,Berar, Surinder,Berar, Urmila,Gupta, Satish C.
experimental part, p. 879 - 885 (2012/04/04)
The photochemical cyclisation of 2-hydroxychalcones leading to the synthesis of 4-flavanones in solution phase has been investigated. The formation of photoproducts has been explained on the basis of excited state intramolecular proton transfer (ESIPT) and the cyclisation efficiency of the chalcones has been found to depend upon the electron density on the phenolic oxygen as well as on the carbonyl group. This synthesis of flavanones by photoirradiation is an eco-friendly route with comparative yield to those of thermal methods. Although the molecular skeletons of these substrates is amenable to cis-trans isomerisations and cycloadditions but no photoproducts corresponding to these reactions have been realized.
