Stereodivergent Allylic Substitutions with Aryl Acetic Acid Esters by Synergistic Iridium and Lewis Base Catalysis
作者:Xingyu Jiang、Jason J. Beiger、John F. Hartwig
DOI:10.1021/jacs.6b11692
日期:2017.1.11
of all possible stereoisomers of a given chiral molecule bearing multiple stereocenters by a simple and unified method is a significant challenge in asymmetric catalysis. We report stereodivergent allylic substitutions with aryl aceticacid esters catalyzed synergistically by a metallacyclic iridium complex and benzotetramisole. Through permutations of the enantiomers of the two chiral catalysts, all
Chemoselective Rh-Catalyzed Allylic Alkylations of Chelated Enolates using Dienylcarbonates
作者:Saskia Hähn、Uli Kazmaier
DOI:10.1002/ejoc.201100350
日期:2011.7.14
catalyst not only for highly regio- but also chemoselectiveallylicalkylations of chelated enolates. In contrast to Pd-catalyzed reactions, the Rh-catalyzed version shows also a high degree of regioretention and proceeds without isomerization. Allylic substrates with competitive allylic subunits react selectively at the sterically least hindered allylic position, in comparison to Ru-catalyzed processes
here is an unprecedented auto‐tandem cooperative catalysis (ATCC) for Morita–Baylis–Hillmancarbonates from isatins and allyliccarbonates using a simple Pd(PPh3)4 precursor. Dissociated phosphine generates phosphorusylides and the Pd leads to π‐allylpalladium complexes, and they undergo a γ‐regioselective allylic–allylic alkylation reaction. Importantly, a cascade intramolecular Heck‐type coupling proceeds
Direct, Intermolecular, Enantioselective, Iridium-Catalyzed Allylation of Carbamates to Form Carbamate-Protected, Branched Allylic Amines
作者:Daniel J. Weix、Dean Marković、Mitsuhiro Ueda、John F. Hartwig
DOI:10.1021/ol901151u
日期:2009.7.2
The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylicamines with high regioselectivity and enantioselectivity is reported. This process occurs without base or with 0.5 equiv K3PO4 in the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted
A Regio‐ and Stereodivergent Synthesis of Homoallylic Amines by a One‐Pot Cooperative‐Catalysis‐Based Allylic Alkylation/Hofmann Rearrangement Strategy
作者:Colin M. Pearson、James W. B. Fyfe、Thomas N. Snaddon
DOI:10.1002/anie.201905426
日期:2019.7.29
Herein, we report a modular synthetic route to linear and branched homoallylic amines that operates through a sequential one-pot Lewis base/transition-metal catalyzed allylic alkylation/Hofmann rearrangement strategy. This protocol is operationally trivial, proceeds from simple and easily prepared substrates and catalysts, and enables all aspects of regio- and stereoselectivity to be controlled through