Facile generation of a reactive palladium(II) enolate intermediate by the decarboxylation of palladium(II) .beta.-ketocarboxylate and its utilization in allylic acylation
An efficient, direct nucleophilic allylicsubstitution of α-, β- and γ-substituted alcohols with enamines, using the Pd(OAc)2/PPh3 catalyst system and ZnBr2 as a promoter in CH2Cl2 at reflux, is reported. The reaction course was dependent on the steric hindrance at the α- or γ-positions with respect to the functionalized α-carbon, selectively affording in moderate to good yields, α- or γ-homoallyl
Free radical allylations of α-seleno carbonyl compounds with tributyl-substituted 2,4-pentadienyltin, 2-methyl-2-propenyltin, 2-butenyltin, and 3-methyl-2-butenyltin, are described. Such successful C–C bond formations, in particular with the 2-butenyltin and the 3-methyl-2-butenyltin, are owing to the high reactivity of the α-carbon radical, generated from α-seleno carbonyl compounds, toward allylic tin compounds.
The reactions of allylic triethylammonium bromides and dimethylsulfonium bromide with carbon nucleophiles were catalyzed by tetrakis(triphenylphosphine)palladium to afford olefinic esters and ketones.
This invention relates to stable liquid formulations of the nitrification inhibitor nitrapyrin comprising polar solvents that are stabilized with small amounts of compounds which help to reduce the tendency of polar solutions of nitrapyrin to corrode metal surfaces. Many of the formulations disclosed herein exhibit useful physical, chemical, and bioactive properties including reduced levels of corrosion when in contact with ferrous metals.
We report a nickel/NHC-catalyzed branched-selective acrotylation of simple ketones using 1,3-butadiene as the alkylation agent. This reaction is regioselective and operated under pH and redox-neutral conditions. Water was used as the sole additive, which significantly accelerates the transformation.