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
A highly selectivecopper-catalyzed concise synthesis of 3,5-diarylpyridine and 2-(1H)-pyridone has been achieved through cascade Chichibabin-type cyclization, C(sp3)–C(sp3) cleavage, and aerobicoxidation. Azide, ceric ammonium nitrate (CAN), and 2-aminopyridine are disclosed as efficient nitrogen donors in this Cu-catalysis using O2 as the oxidant. Water and molecular oxygen were employed as the
method for the synthesis of substituted pyridines with aldehydes and NH4OAc under mild conditions using air as the oxidant was developed. This oxidative cyclization process involves directC–Hbondfunctionalization, C–C/C–N bond formation and C–Cbondcleavage.
bond participation in annulation to pyridines usingN,N-dimethylformamide (DMF) as the N1 and C4 synthons has been carried out. In this reaction, DMF contributed one N atom and one C atom to two disconnected positions of pyridine ring, with no need for an additional nitrogen source. Two C═C bonds in two molecules of substituted styrenes offered four carbon atoms in the presence of iodine and persulfate