188840-13-3Relevant academic research and scientific papers
Nickel-Catalyzed Enantioselective Arylative Activation of Aromatic C-O Bond
Zhang, Jintong,Sun, Tingting,Zhang, Zishuo,Cao, Haiqun,Bai, Zhushuang,Cao, Zhi-Chao
supporting information, p. 18380 - 18387 (2021/11/16)
The pioneering nickel-catalyzed cross-coupling of C-O electrophiles was unlocked by Wenkert in the 1970s; however, the transition-metal-catalyzed asymmetric activation of aromatic C-O bonds has never been reported. Herein the first enantioselective activation of an aromatic C-O bond is demonstrated via the catalytic arylative ring-opening cross-coupling of diarylfurans. This transformation is facilitated via nickel catalysis in the presence of chiral N-heterocyclic carbene ligands, and chiral 2-aryl-2′-hydroxy-1,1′-binaphthyl (ArOBIN) skeletons are delivered axially in high yields with high ee. Moreover, this versatile skeleton can be transformed into various synthetic useful intermediates, chiral catalysts, and ligands by using the CH- and OH-based modifiable sites. This chemistry features mild conditions and good atom economy.
Synthesis, Characterization, and Catalytic Activity of Chiral NHC Platinum(II) Pyridine Dihalide Complexes
Blanc, Aurélien,De Frémont, Pierre,Hatey, Delphine,Pale, Patrick,Pertschi, Romain
supporting information, (2020/03/16)
A series of platinum(II) dihalide pyridine complexes bearing chiral C2-symmetric N-heterocyclic carbene (NHC) ligands [Pt(NHC*)(Py)(Hal)2] was synthesized in a one-pot procedure and characterized by NMR spectroscopy and single crystal X-ray diffraction (SC-XRD). The complexes were tested for the asymmetric cycloisomerization of enynol into bicyclo[3.1.0]hexanone and feature an excellent catalytic activity at room temperature along with a modest enantiomeric induction (up to 39% ee).
Some insights into the gold-catalysed A3-coupling reaction
Price, Gregory A.,Brisdon, Alan K.,Randall, Simon,Lewis, Edward,Whittaker, Daniel M.,Pritchard, Robin G.,Muryn, Chris A.,Flower, Kevin R.,Quayle, Peter
supporting information, p. 251 - 262 (2017/07/06)
A series of cyclometallated and functionalised NHC gold(I) and gold(III) complexes, many of which feature chiral ligands, and their application to A3-coupling reactions is presented. Gold(III) complexes were found to be particularly effective catalysts for the coupling in a range of solvents, however no asymmetric induction was obtained when using chiral gold complexes and the rate of product formation was found to be similar even when using different ligand systems. In-situ NMR analysis of these reactions indicates that decomposition of the catalyst occurs during the course of the reaction while TEM studies revealed the presence of gold nanoparticles in crude reaction mixtures. Taken together these data suggest that the gold nanoparticles, rather than the intact gold complexes, could be the catalytically active species, and if so this may have significant implications for other gold-catalysed systems.
Solvent effects in gold-catalysed A3-coupling reactions
Price, Gregory A.,Brisdon, Alan K.,Flower, Kevin R.,Pritchard, Robin G.,Quayle, Peter
supporting information, p. 151 - 154 (2014/01/06)
Gold-catalysed A3-reactions proceed efficiently when conducted in 2,2,2-trifluoroethanol as solvent. The rates of these reactions are accelerated considerably when conducted in a microwave reactor.
Enantioselective copper catalysed 1,4-conjugate addition reactions using chiral N-heterocyclic carbenes
Winn, Caroline L.,Guillen, Frédéric,Pytkowicz, Julien,Roland, Sylvain,Mangeney, Pierre,Alexakis, Alexandre
, p. 5672 - 5695 (2007/10/03)
The preparation of a variety of chiral N-heterocyclic carbene (NHC) precursors is described. The relative merits of imidazolinium salts and silver carbenes as NHC precursors are discussed with respect to their synthesis, stability and performance in the copper catalysed conjugate addition of dialkyl zinc reagents to a variety of Michael acceptors. Enantioselectivities of up to 93% were achieved using as little as 4% of chiral ligand.
