The Effect of Hydrogen Bonding on Allylic Alkylation and Isomerization Reactions in Ionic Liquids
作者:James Ross、Jianliang Xiao
DOI:10.1002/chem.200304895
日期:2003.10.17
Neutral allylic alkylation reactions, in which a base is generated in situ and which hence require no external bases, can significantly be retarded when carried out in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)]). Evidence suggests that the base or base precursor enters into hydrogen bonding with the imidazolium cation and is thus made less readily available for deprotonation
A New Class of Non-<i>C</i><sub>2</sub>-Symmetric Ligands for Oxidative and Redox-Neutral Palladium-Catalyzed Asymmetric Allylic Alkylations of 1,3-Diketones
作者:Barry M. Trost、Etienne J. Donckele、David A. Thaisrivongs、Maksim Osipov、James T. Masters
DOI:10.1021/jacs.5b00786
日期:2015.2.25
We report the discovery, synthesis, and application of a new class of non-C-2-symmetric phosphoramidite ligands derived from pyroglutamic acid for use in both oxidative and redox-neutral palladium-catalyzed asymmetric allylic alkylations of 1,3-diketones. The resulting chiral products are typically obtained in high yield with good to excellent levels of enantioselectivity.
Catalytic Intermolecular Allylic C—H Alkylation
作者:Andrew J. Young、M. Christina White
DOI:10.1021/ja806867p
日期:2008.10.29
The first electrophilic Pd(II)-catalyzed allylic C H alkylation is reported, providing a novel method for formation of sp3-sp3 C C bonds directly from C H bonds. A wide range of aromatic and heteroaromatic linear (E)-alpha-nitro-arylpentenoates are obtained as single olefin isomers in excellent yields directly from terminal olefin substrates and methyl nitroacetate. The use of DMSO as a pi-acidic ligand