The synthesis of 2,4-disubstituted pyrrolo[1,2-a]quinoxalinesfrom chalcones is reported. The key steps used are polyphosphoric acid (PPA) assisted acyl rearrangement of the pyrrole ring and Fe catalyzed reduction-cyclization leading to 2,4-disubstituted pyrrolo[1,2-a]quinoxalines. Despite the utilization of comparatively unreactive aromatic ketones, modest to good yields were obtained.
Synthesis of highly functionalized 7-azabicyclo[2.2.1]heptadienes
作者:Zhengming Chen、Mark L. Trudell
DOI:10.1016/0040-4039(94)88350-5
日期:1994.12
Highly functionalized 7-azabicyclo[2.2.1]heptadiene derivatives have been synthesized via a [4 + 2] cycloaddition reaction between N-acyl-3,4-disubstituted pyrroles and ethynyl p-tolyl sulfone 5.
CAN-Mediated Oxidative Cyclodehydrogenation of Hexapyrrolylbenzenes
作者:Ravi P. Singh、Satish K. Pandey、Vijay Gupta
DOI:10.1055/s-0040-1707822
日期:2020.8
An efficient method for ceric ammonium nitrate mediated synthesis of annularly fused hexapyrrolohexaazacoronene by oxidative cyclodehydrogenation has been reported. The photophysical properties of the representative hexaazacoronene has also been described.
Pd-Catalyzed regioselective intramolecular dehydrogenative C-5 cross coupling in an<i>N</i>-substituted pyrrole-azole system
作者:Krishna N. Tripathi、Devalina Ray、Ravi P. Singh
DOI:10.1039/c7ob02676e
日期:——
Functionalized polycyclic pyrrole-azole structures possessing fused six membered and seven membered rings were directly synthesized via ligand-enabled, Pd-catalyzed, site selective, intramolecular cross couplings of N-substituted pyrrole-azoles. C5-H activation in the presence of a reactive C2-H remains a challenge that needs to be addressed and this was targeted to be resolved through the present
Tandem Michael addition/isocyanide insertion into the C–C bond: a novel access to 2-acylpyrroles and medium-ring fused pyrroles
作者:Lingjuan Zhang、Xianxiu Xu、Qiu-rong Shao、Ling Pan、Qun Liu
DOI:10.1039/c3ob41793j
日期:——
A new reaction model, tandem Michael addition/formal isocyanide insertion into the acyl C–C bond, has been developed. Thus, a series of 2-acylpyrroles and seven-/eight-membered ring fusedpyrroles were synthesized from the reaction of methyl isocyanides with enones in a single operation.