Tetrasubstituted Olefins through the Stereoselective Catalytic Intermolecular Conjugate Addition of Simple Alkenes to α,β-Unsaturated Carbonyl Compounds
作者:Ki-Hyeok Kwon、Do W. Lee、Chae S. Yi
DOI:10.1002/anie.201006411
日期:2011.2.11
Branching out: The cationic ruthenium–hydride complex [Ru]+ was found to be a highly effective catalyst precursor for the conjugate addition of unactivated olefins to α,β‐unsaturated carbonylcompounds to yield tetrasubstituted olefins. A kinetic analysis provides support for the mechanism involving a regioselective olefin insertion and rapid alkene isomerization steps.
Catalytic, Enantioselective 1,2-Difluorination of Cinnamamides
作者:Moriana K. Haj、Steven M. Banik、Eric N. Jacobsen
DOI:10.1021/acs.orglett.9b00938
日期:2019.7.5
The enantio- and diastereoselective synthesis of 1,2-difluorides via chiral aryl iodide-catalyzed difluorination of cinnamamides is reported. The method uses HF-pyridine as a fluoride source and mCPBA as a stoichiometric oxidant to turn over catalyst, and affords compounds containing vicinal, fluoride-bearing stereocenters. Selectivity for 1,2-difluorination versus a rearrangement pathway resulting in 1,1-difluorination is enforced through anchimeric assistance from a N-tert-butyl amide substituent.
Co(III)-Catalyzed [4+1] Annulation of Amides with Allenes via C−H Activation
Co(III)‐catalyzed [4+1] annulation of amides with allenes to synthesize isoindolone and 1,5‐dihydro‐pyrrol‐2‐one derivatives is reported. A wide range of aromatic and vinylic amides react with allenes to give the corresponding annulation products in good to excellent yields. The mechanistic studies strongly support that the catalytic reaction proceeds through an amide‐directed C−Hactivation, followed
Organophotocatalytic N–O Bond Cleavage of Weinreb Amides: Mechanism-Guided Evolution of a PET to ConPET Platform
作者:Julia Soika、Calum McLaughlin、Tomáš Neveselý、Constantin G. Daniliuc、John. J. Molloy、Ryan Gilmour
DOI:10.1021/acscatal.2c02991
日期:2022.8.19
A mild, organophotocatalytic N–O bond cleavage of Weinrebamides is disclosed, thereby expanding the chemistry of this venerable motif beyond acylation. This redox neutral process begins to reconcile the ubiquity of N–O bonds in contemporary synthesis with the disproportionately harsh, stoichiometric conditions that are often required for bond cleavage. The strategy is compatible with the parent alkyl