85439-24-3Relevant academic research and scientific papers
Stereoselectivities in AgBF4-catalyzed and photoinduced phenyl- rearrangement of 2-chloropropiophenone
Usui, Satoshi,Matsumoto, Takeshi,Ohkubo, Katsutoshi
, p. 9755 - 9758 (2007/10/03)
(S)-2-Phenylpropionic acid was stereoselectively obtained by the AgBF4- catalyzed phenyl-rearrangement of (S)-2-chloropropiophenone dimethyl acetal, while the photoirradiation of (S)- or (R)-2-chloropropiophenone afforded partially racemized (S)-or (R)-2-phenylpropionic acid, respectively. An intramolecular S(N)2 mechanism is suggested for the former rearrangement. The latter result is indicative of the intervention of an ion or radical intermediate in the photoinduced phenyl-rearrangement.
Photochemical Rearrangement of α-Chloro-Propiophenones to α-Arylpropanoic Acids: Studies on Chirality Transfer and Synthesis of (S)-(+)-Ibuprofen and (S)-(+)-Ketoprofen
Sonawane, Harikisan,Bellur, Nanjundiah S.,Kulkarni, Dilip G.,Ayyangar, Nagaraj R.
, p. 1243 - 1260 (2007/10/02)
A new single-step efficient photochemical approach for α-arylpropanoic acids (4) from α-chloro-propiophenones (5) is described.It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent.The mode of the rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones.The results suggest that the nature of the carbonyl triplets (n, ?*/ ?, ?*) plays an important role in the chirality transfer.This method finds application in the synthesis of optically active ibuprofen (4e) and ketoprofen (26), though in moderate optical yields.
