A new class of N-doped ionic PAHs<i>via</i>intramolecular [4+2]-cycloaddition between arylpyridines and alkynes
作者:Ravindra D. Mule、Aslam C. Shaikh、Amol B. Gade、Nitin T. Patil
DOI:10.1039/c8cc05743e
日期:——
Reported herein, for the first time, is a copper-promoted intramolecular [4+2]-cycloaddition cascade to access ionic N-doped polycyclic aromatic hydrocarbons (PAHs) with tunable emission wavelengths. It is shown that the reaction can be made catalytic with respect to Cu(OTf)2 when an external oxidant, Selectfluor, was used.
Selective palladium-catalysed arylation of 2,6-dibromopyridine using N-heterocyclic carbene ligands
作者:D. Prajapati、C. Schulzke、M. K. Kindermann、A. R. Kapdi
DOI:10.1039/c5ra10561g
日期:——
A selective palladium-catalysed arylation of 2,6-dibromopyridine has been developed by employing N-heterocyclic carbene ligands. Selective mono-arylation was performed in water/acetonitrile solvent system at ambient temperature with catalyst loading of 0.1 mol%. This reaction was also found to proceed smoothly in water although at a slightly elevated temperature of 80 °C. 2,6-Disubstituted and diversely
exhibited a linear relationship and a reaction parameter (ρ)=+0.56±0.02, which indicated that the trifluoromethylation reaction proceeded via a nucleophilic reactive species. Complex 2 reacts with phenols to produce aryl difluoromethyl ethers in modest‐to‐excellent yields. Mechanisticinvestigations revealed that the difluoromethylation reaction proceeds by initial copper‐mediated formation of difluorocarbene
Triarylbismuthanes as Threefold Aryl-Transfer Reagents in Regioselective Cross-Coupling Reactions with Bromopyridines and Quinolines
作者:Maddali L. N. Rao、Ritesh J. Dhanorkar
DOI:10.1002/ejoc.201402455
日期:2014.8
Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot