Asymmetric Synthesis of γ-Nitroesters by an Organocatalytic One-Pot Strategy
作者:Kim L. Jensen、Pernille H. Poulsen、Bjarke S. Donslund、Fabio Morana、Karl Anker Jørgensen
DOI:10.1021/ol3002514
日期:2012.3.16
An enantioselective synthesis of γ-nitroesters by a one-pot asymmetric Michaeladdition/oxidative esterification of α,β-unsaturatedaldehydes is presented. The procedure is based on merging the enantioselective organocatalytic nitroalkane addition with an N-bromosuccinimide-based oxidation. The γ-nitroesters are obtained in good yields and enantioselectivities, and the method provides an attractive
A highly efficient N,N′-dioxide/Gd(III) complex has been developed for the enantioselective conjugate addition of nitroalkanes to α,β-unsaturated pyrazolamides. Under mild reaction conditions, a series of γ-nitropyrazolamides were obtained in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 99% ee). What’s more, the optically active products could be easily transformed
A Chiral‐at‐Metal Iridium Catalyst with Two Simple but Sterically Demanding Cyclometalated N‐Heterocyclic Carbene Ligands
作者:Yuqi Tan、Klaus Harms、Eric Meggers
DOI:10.1002/ejic.201800450
日期:2018.6.15
A new member of the family of chiral‐at‐metal, bis‐cyclometalated iridium(III) catalysts featuring exclusively metal‐centered chirality is introduced, which emphasizes the simplicity of the organic ligand design. The catalyst is built from readily available 1,3‐bis(p‐tolyl)imidazolium chloride, which, upon double deprotonation, serves as a cyclometalated N‐heterocyclic carbene. The resulting configurationally