Catalytic asymmetric intramolecular homologation of ketones with α-diazoesters: Synthesis of cyclic α-Aryl/Alkyl β-ketoesters
A catalytic asymmetric intramolecular homologation of simple ketones with α-diazoesters was firstly accomplished with a chiral N,N′-dioxide-Sc(OTf)3 complex. This method provides an efficient access to chiral cyclic α-aryl/alkyl β-ketoesters containing an all-carbon quaternary stereocenter. Under mild conditions, a variety of aryl- and alkyl-substituted ketone groups reacted with α-diazoester groups smoothly through an intramolecular addition/rearrangement process, producing the β-ketoesters in high yield and enantiomeric excess.
D2 ANTAGONISTS, METHODS OF SYNTHESIS AND METHODS OF USE
Provided are D2 or D3 antagonist compounds and pharmaceutical compositions of formula I and pharmaceutically acceptable salts thereof, or isomers thereof, wherein R1, R2 and R3 are as defined herein. The invention further comprises methods for making the compounds of the invention and methods for the treatment of conditions mediated by the dopamine D2 or D3 receptor from the compounds of the invention.
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Page/Page column 76
(2012/01/06)
Synthesis of γ-halogenated ketones via the Ce(IV)-mediated oxidative coupling of cyclobutanols and inorganic halides
A straightforward method for the synthesis of γ-halo-substituted ketones formed via the CAN-initiated oxidative addition of halides to 1-substituted cyclobutanols has been developed. This method has short reaction times, and provides access to a range of bromo and iodo γ-substituted ketones in good to excellent yields.
Casey, Brian M.,Eakin, Cynthia A.,Flowers II, Robert A.
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p. 1264 - 1266
(2009/09/05)
New efficient nickel-catalyzed cross-coupling reaction between two Csp3 centers
The presence of a remote unsaturation (double bond, carbonyl group, cyano group) in an alkyl halide facilitates its cross-coupling reaction with various diorganozincs in the presence of Ni(acac)2 (7.5-10 mol % in THF/NMP mixtures). These results were used to develop a new general cross-coupling reaction between functionalized diorganozincs and alkyl iodides using m- or p-trifluoromethylstyrene as a reaction promotor and Ni(acac)2 as a catalyst (7.5-10 mol %; -35 °C, 5-10 h) leading to a broad range of polyfunctional cross-coupling products.