Chemistry of thienopyridines. XX. The relation of dipole moment to molecular structure

Abstract

Dipole moments were measured for three bicyclic thienopyridines and three tetracyclic diben‐zothienopyridines in benzene solution at 25°. Results agreed closely with predicted values based on vector addition of dipole moments for reference constituent compounds.

Cascade Radical Reaction of 2-Alkynyl-Substituted Aryl Radicals with Aryl Isothiocyanates: A Novel Entry to Benzothieno[2,3-b]quinolines through α-(Arylsulfanyl)imidoyl Radicals

“…In this work we have devised a novel protocol for the one-pot construction of benzothieno[2,3- b ]quinolines, for whose b -fused quinoline structure, surprisingly, literature examples are almost totally absent . Our protocol is based on a radical cascade reaction that entails a rare [3 + 2] annulation and is initiated by a still uncommon addition of an aryl radical to an isothiocyanate.…”

“…In view of our long interest in the chemical reactivity and utility of imidoyl radicals, ,2d-l, we were next prompted to search for a further synthetic use for the α-sulfanylated members by examining related addition reactions of 2-alkynylaryl radicals with aryl isothiocyanates. We considered that derived α-(2-alkynylarylsulfanyl)imidoyl radicals might usefully lead to (virtually unknown) benzothieno[2,3- b ]quinolines through a mechanistic route similar to that we had discovered for the α-(2-cyanoarylsulfanyl)-substituted analogues. Herein we report our successful results from a study of the reactions of the 2-(phenylethynyl)phenyl radical 3 and its 4-cyano derivative 4 with some aryl isothiocyanates 5 − 9 , as shown in Scheme .…”