The First Fluoride‐Free Hiyama Reaction of Vinylsiloxanes Promoted by Sodium Hydroxide in Water

Abstract

The first cross-coupling reaction between vinylalkoxysilanes and aryl bromides or chlorides promoted by aqueous sodium hydroxide under fluoride-free conditions to provide styrenes is reported. The reaction is catalyzed by palladium(II) acetate or a 4-hydroxyacetophenone oxime-derived palladacycle either under thermal or microwave heating at 120 8C with low catalyst loading (0.01-1 mol % of palladium) in the presence of tetra-n-butylammonium bromide (TBAB) as additive in air. In the case of styryltriethoxysilane, the coupling with aryl or vinyl bromides takes place stereospecifically to give the corresponding stilbenes or dienes, respectively. These mild and simple reaction conditions prevent undesirable polymerization of the products.

Kaiser oxime resin-derived palladacycle: A recoverable polymeric precatalyst in Suzuki–Miyaura reactions in aqueous media

“…In our previous work, we have reported that dimeric oxime-derived carbapalladacycles 1 [7] and 2 [8] are excellent precatalysts in cross-coupling reactions under phosphine-free conditions such as, Heck, Stille, Suzuki, Ullmann, Sonogashira, Hiyama, and Glaser in organic and aqueous media, being even more efficient than Pd salts [9]. Cross-coupling processes such as Suzuki [8a,b,m] and Hiyama [8h,i,j] reactions could be performed using water as solvent even with hydrophobic substrates. The great importance of using water as a reaction solvent, specially in palladium-catalysed cross-coupling reactions has been highlighted in recent years [10].…”

Facile Synthesis of Hyper‐Branched Tetraphosphanes and Tetraphosphane Chalcogenides

“…Spectral characteristics of 16 correspond to the reference data. [28] Supporting Information (see footnote on the first page of this article): Characterization data of 8-13 and copies of the 1 H, 13 C, and 31 P NMR spectra of new compounds.…”

Reactivity of functionalized thiosemicarbazone complexes towards phosphines

“…These have aroused great interest due to their wide range of applications. Their biological activity depends on the parent aldehyde or ketone [1][2][3]; also, palladium (II) complexes have proved to be useful as catalysts in cross coupling reactions like the Heck and Suzuki-Miyaura cross-coupling reaction [4][5][6][7].…”