Palladium-Catalyzed Allylic Alkylation of Simple Ketones with Allylic Alcohols and Its Mechanistic Study
作者:Xiaohong Huo、Guoqiang Yang、Delong Liu、Yangang Liu、Ilya D. Gridnev、Wanbin Zhang
DOI:10.1002/anie.201403410
日期:2014.6.23
Allylicalcohols were directly used in Pd‐catalyzed allylicalkylations of simpleketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co‐catalyst, and a hydrogen‐bonding solvent, and does not require any additional reagents. A computational study suggested that methanol plays a crucial role in the formation of the
Halonium Ion-Mediated Reaction of Unsaturated Hydroperoxy Acetals. Competition between the Formation of Cyclic Peroxides and the Migration of the Methoxy (or Hydroxy) Group
作者:Takahiro Tokuyasu、Araki Masuyama、Masatomo Nojima、Kevin J. McCullough
DOI:10.1021/jo991499m
日期:2000.2.1
Monoozonolyses of dienes 2 in methanol gave in each case the corresponding unsaturated alpha-methoxy hydroperoxides 3. Capture of 2-alkyl-substituted cyclohexanone oxides by methanol was highly diastereoselective, thereby providing exclusively the hydroperoxides derived from attack by methanol from the less hindered face of the carbonyl oxide intermediates. Halonium ion-mediated reactions of the hydroperoxides
Trialkylsilyl triflimides as easily tunable organocatalysts for allylation and benzylation of silyl carbon nucleophiles with non-genotoxic reagents
作者:Oscar Mendoza、Guy Rossey、Léon Ghosez
DOI:10.1016/j.tetlet.2010.03.030
日期:2010.5
Trialkylsilyl triflimides generated in situ are unique catalysts for the electrophilic benzylation or allylation of trialkylsilylenol ethers or allyl trialkylsilanes with non-genotoxic alkylating reagents such as benzyl and allyl acetates. In most cases the reactions are fast at room temperature and yields are high. The reaction works particularly well with electron-rich benzyl donors including derivatives
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
accessible tertiary propargyl vinyl ethers as substrates and imidazole as a catalyst to form up to two new rings, three new C−C bonds, six stereogenic centers and one transannular oxo‐bridge. The manifold is efficient, scalable and instrumentally simple to perform and entails a propargyl Claisen rearrangement–[1,3]H shift, an oxa‐6π‐electrocyclization, and an intramolecularDiels–Alderreaction.