Palladium-catalysed direct synthesis of benzo[b]thiophenes from thioenols

Abstract

The one-pot conversion of thioenols into benzo[b]thiophenes was achieved by using a simple palladium catalyst such as PdCl(2) or PdCl(2)(cod).

Copper-catalyzed ortho-acylation of phenols with aryl aldehydes and its application in one-step preparation of xanthones

“…3 However, classical Friedel-Crafts reactions often suffer from the harsh reaction condition and usage of air/water sensitive Lewis acid. 4 While transition-metal-catalyzed C-H activation can convert carbon-hydrogen bond into carbon-oxygen, 5 carbon-nitrogen, 6 carbon-halide, 7 carbon-sulfur 8 or carbon-carbon bonds, 9 till now, there is only one report about the acylation reaction of unprotected phenols. 10 In that work, Miura and co-workers prepared 2-benzoyl-1-naphthol as a control experiment when they synthesized benzofuran-2(3H)-ones; however, no in-depth investigation was reported.…”

Heterocycle Synthesis Based on Palladium-Catalyzed C-H Bond Functionalization Methods

“…The synthesis of substituted benzothiophenes is a rare example of heterocycle synthesis based on palladium-catalyzed C H activation/C S bond forming strategy (Scheme 56) [84]. The regioselective cyclization of thioenols took pace in DMSO using PdCl 2 , as a catalyst.…”

Pd‐Catalyzed Synthesis of Other Heteroatom‐Containing Heterocycles

“…In 2008, a breakthrough was achieved by Doi and coworkers, who employed thioenols to synthesize of multisubstituted benzo [b]thiophenes by using palladium catalyst such as PdCl 2 or PdCl 2 (cod) (Scheme 4.1) [6]. Surprisingly, this transformation proceeded more efficiently in the absence of reoxidants, and they found DMSO is crucial for high conversion in this process.…”