52889-85-7Relevant academic research and scientific papers
Catalytic Olefin Hydroamidation Enabled by Proton-Coupled Electron Transfer
Miller, David C.,Choi, Gilbert J.,Orbe, Hudson S.,Knowles, Robert R.
supporting information, p. 13492 - 13495 (2015/11/09)
Here we report a ternary catalyst system for the intramolecular hydroamidation of unactivated olefins using simple N-aryl amide derivatives. Amide activation in these reactions occurs via concerted proton-coupled electron transfer (PCET) mediated by an excited state iridium complex and weak phosphate base to furnish a reactive amidyl radical that readily adds to pendant alkenes. A series of H-atom, electron, and proton transfer events with a thiophenol cocatalyst furnish the product and regenerate the active forms of the photocatalyst and base. Mechanistic studies indicate that the amide substrate can be selectively homolyzed via PCET in the presence of the thiophenol, despite a large difference in bond dissociation free energies between these functional groups.
Design of chiral boronate-substituted acrylanilides. Self-activation and boron-transmitted 1,8-stereoinduction in [4+2] cycloaddition
Kennedy, Jason W.J.,Hall, Dennis G.
, p. 263 - 270 (2007/10/03)
The [4+2] cycloaddition of ortho-boronoanilide dienophile 4 with cyclopentadiene was found to proceed faster than both its para isomer 8 and the unsubstituted derivative 6, thereby confirming that self-activation by internal coordination is operative in the case of 4. Chiral boronic esters derivatives 9-13 provided a small level of remote 1,8-stereoinduction transmitted through a putative tetrahedral stereogenic boronate complex. These results show that dialkoxyboronic esters can operate as weak, internal Lewis acids and activate carbonyl-containing functionalities in cycloaddition reactions.
Self-activation and 1,8-stereoinduction in a boronate-substituted dienophile
Kennedy, Jason W. J.,Hall, Dennis G.
, p. 477 - 479 (2007/10/03)
The [4+2] cycloaddition of ortho-boronoanilide dienophile 4 with cyclopentadiene was found to proceed faster than both its para isomer 8 and the unsubstituted derivative 6, thereby confirming that self-activation by internal coordination is operative in the case of 4. Chiral boronic esters derivatives 9 and 10 provided a small level of remote 1,8-stereoinduction. These results show that dialkoxyboronic esters can operate as weak, internal Lewis acids and activate carbonyl-containing functionalities in cycloaddition reactions.
N-Heterocyclic carbenes: Application of ruthenium-alkylidene complexes in ring-opening metathesis polymerization
Frenzel, Ulrich,Weskamp, Thomas,Kohl, Florian J.,Schattenmann, Wolfgang C.,Nuyken, Oskar,Herrmann, Wolfgang A.
, p. 263 - 265 (2007/10/03)
Novel ruthenium-alkylidene catalysts bearing N-heterocyclic carbenes were applied in ring-opening metathesic polymerization (ROMP) reactions of various norbornene derivatives. High tolerance towards polar functional groups as well as high catalytic activity is demonstrated. The combination of N-heterocyclic carbenes and coordinatively labile ligands (phosphanes or chloro-bridged transition metals) on the ruthenium center proves not only successful regarding catalytic performance but also promising with respect to polymer properties.
