Iodide-Mediated or Iodide-Catalyzed Demethylation and Friedel–Crafts C–H Borylative Cyclization Leading to Thiophene-Fused 1,2-Oxaborine Derivatives
摘要:
The first synthesis of dithieno-1,2-oxaborine derivatives was achieved via iodide-mediated or iodide-catalyzed demethylation of 3-methoxy-2,2'-bithiophene and subsequent C-H borylation. A wide variety of thiophene-fused oxaborines could be synthesized by the procedure.
A new method for the catalytic C-H arylation of heteroarenes and arenes that manifests high activity paired with reasonably broad scope was developed. Under the catalytic influence of RhCl(CO)P[OCH(CF3)2]3}2 and Ag2CO3, the direct C-H arylation of heteroarenes/arenes with aryl/heteroaryl iodides took place to afford a range of biaryls in good to excellent yields with high regioselectivity. Thiophenes, furans, pyrroles, indoles, and alkoxybenzenes are applicable in this arylation protocol.
Direct coupling of arenes and iodoarenes catalyzed by a rhodium complex with a strongly π-accepting phosphite ligand
A new rhodium-based catalytic system for the direct C-H coupling of arenes and iodoarenes that shows high activity with reasonably broad scope was developed. Under the catalytic influence of RhCl(CO)P[OCH(CF3)(2)](3)}(2) and Ag2CO3, the direct C-H arylation of heteroarenes and arenes took place with iodoarenes to afford a range of biaryls in good to excellent yields with high regioselectivity. Thiophenes, furans, pyrroles, indoles, and alkoxybenzenes are applicable to this arylation protocol. (C) 2008 Elsevier Ltd. All rights reserved.