Regiospecific Synthesis of 2-Halo-3-(2′-glucalyl)benzo[b]thiophenes

Abstract

A regiospecific synthetic strategy for the synthesis of 2-chloro-3-substituted benzo[b]thiophenes is developed via a dichlorocarbene insertion and sigmatropic rearrangement of an in situ generated ylide. The current protocol provides a reversed regiochemistry to the commonly employed electrophilic cyclization reaction for the synthesis of benzo[b]thiophenes and access to their hitherto under-represented chlorinated derivatives.

Iodine‐ and PhI(OAc)2‐Mediated Multicomponent Synthesis of (E)‐1,3‐Diphenyl‐1‐butene Derivatives

“…The attractiveness of the protocol is its ability to Scheme 1. In continuation of our interest in the synthesis of organosulfur compounds, [31][32][33][34][35] we herein report a regio-and stereoselective three-component synthesis of novel (E)-1,3-diphenyl-1butene derivatives 7, that contain a sulfur atom, in the absence of a metal or a strong acid catalyst (Scheme 1b). …”

“…For instance, Wacharasindhu et al exploited the environmental compatibility and readily availability of diacetoxy-iodobenzene (DIB) in the activation of thiols for the construction of S-S and S-N bonds and further applied the method in the sulfenylation of indoles. In continuation of our interest in the synthesis of organosulfur compounds, [31][32][33][34][35] we herein report a regio-and stereoselective three-component synthesis of novel (E)-1,3-diphenyl-1butene derivatives 7, that contain a sulfur atom, in the absence of a metal or a strong acid catalyst (Scheme 1b). In continuation of our interest in the synthesis of organosulfur compounds, [31][32][33][34][35] we herein report a regio-and stereoselective three-component synthesis of novel (E)-1,3-diphenyl-1butene derivatives 7, that contain a sulfur atom, in the absence of a metal or a strong acid catalyst (Scheme 1b).…”

One-Pot Synthesis of Functionalized Benzo[b]thiophenes and Their Hetero-Fused Analogues via Intramolecular Copper-Catalyzed S-Arylation of In Situ Generated Enethiolates

“…These reactions, although selective and efficient, however, require prior synthesis of difficult to access prefunctionalized thiophenol precursors . Recently, copper-catalyzed (or Pd-catalyzed) double thiolation of o -(2-halovinyl)­halobenzenes or 2-bromoalkynylbenzenes with metal sulfides or its surrogates, – leading to 2-substituted benzo­[ b ]­thiophenes, has also been reported . These methods involve concomitant formation of S(1)–C­(7a) and S(1)–C(2) bonds of benzo­[ b ]­thiophenes.…”

Diastereoselective Synthesis of Novel and Enantiopure Tetrahydropyrano[3,2-c]quinolines

“…[22][23][24][25][26][27] We recently reported the diastereoselective synthesis of carbohydrate-based thiochroman derivatives 12 possessing antimalarial properties via a Lewis acid catalyzed intramolecular Friedel-Crafts alkylation of 2-C-branched phenylthiomethyl glucopyranosyl 8 as shown in Scheme 1 (b). [28][29][30][31][32][33] The analogy of the oxycarbonium intermediate 10 in Scheme 1 (b) to the oxycarbonium intermediate 5 in Scheme 1 (a), prompted us to synthesize a nitrogen analogue of the 2-C-branched phenylthiomethyl glucopyranosyl 8 and investigate if our established thiochroman synthesis methodology can be adopted to synthesize novel carbohydrate-based tetrahydropyranoquinolines in a diastereoselective fashion in addressing some of the limitations of the Povarov reaction.…”