Nitrative bicyclization of 1,7-diynes for accessing skeletally diverse tricyclic pyrroles

Abstract

A novel metal-free nitrative bicyclization of 1,7-diynes with tBuONO in the presence of H2O is reported, producing three types of skeletally diverse tricyclic pyrroles such as pyrrolo[3,4-c]quinolines, chromeno[3,4-c]pyrroles and benzo[e]isoindoles...

Green and Efficient Construction of Chromeno[3,4-c]pyrrole Core via Barton–Zard Reaction from 3-Nitro-2H-chromenes and Ethyl Isocyanoacetate

“…Samanta et al reported the synthesis of 2-(2,4-dihydrochromeno[3,4- c ]pyrrol-1-yl)acetates 8 from 3-(3-formyl-2 H -chromen-4-yl)acrylates 7 by treatment with hydroxylamine hydrochloride, amino alcohols or sodium azide [ 19 , 20 ]. Recently, a metal-free method for the synthesis of chromeno[3,4- c ]pyrroles 9 based on nitrative cyclization of the corresponding 1,7-diynes with tert -butyl nitrite in the presence of water has been developed [ 21 ].…”

Multicomponent Annulative SO2 Insertion of Heteroatom‐Linked 1,7‐Diynes for Accessing Tricyclic Sulfones

“…In the past few years, our group has been engaging in the development of radicaltriggered annulation reactions of 1,n-diynes that can render easy access to some important cyclic molecules for downstream studies in chemical biology and pharmaceutical chemistry. [13] During this project, we reasoned that sulfonyl radicals derived from aryl diazonium tetrafluoroborates and DABSO under thermolytic conditions could regioselectively add to heteroatom-linked 1,7-diynes, followed by 6-exo-dig cyclization and annulative SO 2 insertion to produce tricyclic sulfones. Such an approach enables the realization of exocyclic and annulative double SO 2 insertion.…”