Palladium-Catalyzed Cross-Coupling of Silanols, Silanediols, and Silanetriols Promoted by Silver(I) Oxide

Abstract

Palladium-catalyzed cross-coupling of aryl- or alkenylsilanols, silanediols, and silanetriols with a variety of iodoarenes by the catalysis of palladium(0) and in the presence of silver(I) oxide furnished the coupling products in good to excellent yields. The reactions of silanediols or silanetriols under similar conditions proceeded much faster than those of silanols to afford the corresponding coupling products in excellent yields within shorter reaction periods (5-12 h). The measurement of the X-ray diffraction (XRD) pattern of the silver residue after the reaction revealed that silver(I) oxide was converted to silver(I) iodide.

Vinyl tris(trimethylsilyl)silanes: substrates for Hiyama coupling

“…Thus, coupling of conjugated silanes 2a-d with aryl, heterocyclic, and aliphatic bromides or iodides (H 2 O 2 /NaOH/Pd(0)/TBAF) provided products stereoselectively in good to excellent yields (48-90%, Table 3, entries [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The electron-deficient aryl iodides gave to some extent higher yields than the electron rich aryl iodides in the reactions with silane 2a (entries 1, 3 and 4).…”

At the Edge of Stability – Preparation of Methyl‐substituted Arylsilanetriols and Investigation of their Condensation Behavior

“…[40] The published protocol for this procedure uses in situ prepared silanetriol without further purification or characterization. According to our findings it is likely that significant amounts of the corresponding disiloxanetetrol are formed concomitantly with currently unknown consequences for the subsequent catalytic conversions.…”

“…To obtain the envisaged silanetriols 3a-c, the corresponding trichlorosilanes 1a-c were hydrolyzed in ether solution in the presence of three equivalents of NaHCO 3 following an established procedure by Hirabayashi et al [40] Silanetriols 3a-c can be isolated by precipitation with pentane from a concentrated ethereal solution as colorless powder. The 29 Si-NMR resonances of these products can be observed in the range of -50.8 ppm to -51.7 ppm ([D 6 ]acetone).…”

C-C Cross-Coupling: New Methodologies, Applications and Discoveries over the Last Few Years

“…[62][63][64][65] 66 Dentre todos os complexos de paládio testados na reação modelo entre iodobenzeno e trifenilfosfino-vinil-ouro, o melhor resultado foi obtido na presença de PdCl 2 (dppf). Ligantes bidentados, como o dppf, são incapazes de quelar espécies de Au (I), através de geometria de coordenação linear, e por isso a transferência do mesmo do complexo de paládio, ao centro de ouro é impossibilitado.…”