Catalytic Cross-Coupling of Alkylzinc Halides with α-Chloroketones
作者:Chrysa F. Malosh、Joseph M. Ready
DOI:10.1021/ja0467768
日期:2004.8.1
this method, primary and secondary alkyl groups are introduced adjacent to a ketone carbonyl under mild reaction conditions and in good yield. Cyclic, acyclic, aromatic, and aliphatic α-chloroketones are suitable substrates. Opticallyactive α-chloroketones are converted to opticallyactive products. The reaction was found to proceed stereospecifically with inversion of stereochemistry. The reaction
Photochemical rearrangement of α-chloro-propiophenones to α-arylpropanoic acids: studies on chirality transfer and synthesis of (S)-(+)-ibuprofen and (S)-(+)-ketoprofen
作者:Harikisan R. Sonawane、Nanjundiah S. Bellur、Dilip G. Kulkarni、Nagaraj R. Ayyangar
DOI:10.1016/s0040-4020(01)80835-8
日期:1994.1
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 this rearrangement is probed by the study of the photobehaviour of a set of opticallyactive α-chloro-propiophenones. The results suggest that the nature of
(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. (C) 1998 Elsevier Science Ltd. All rights reserved.
Sonawane Harikisan R., Bellur Nanjundiah S., Kulkarni Dilip G., Ayyangar +, Tetrahedron, 50 (1994) N 4, S 1243-1260