Palladium/Norbornene Chemistry: Synthesis of Norbornene-Containing Arylsilanes Involving Double C–Si Bond Formation

Abstract

A novel palladium-catalyzed three-component cascade reaction of aryl halides with norbornene and hexamethyldisilane has been described, which allows the simultaneous construction of two C–Si bonds and one C–C bond. The method achieves ortho C–H functionalization of aryl halides through the formation of the five-membered palladacycle, leading to norbornene-containing arylsilanes.

Palladium/Norbornene Cooperative Catalysis

“…Later, it was shown that the use of anilines or ureas could lead to similar products . Recently, disilanes was also found to be able to intercept the ANP intermediate by the Zhang, Cheng, , and Liang groups. Due to the facile C–Si reductive elimination, NBE-containing bis-silylated products were obtained.…”

NBE-Controlled Palladium-Catalyzed Interannular Selective C–H Silylation: Access to Divergent Silicon-Containing 1,1′-Biaryl-2-Acetamides

“…Very recently, the Chen , and Our groups simultaneously demonstrated palladium-catalyzed Catellani-type ortho -silylation of aryl iodides. On the basis of recent reports and our ongoing interests in the tandem reactions involving palladacycles, herein we successfully achieved palladium-catalyzed interannular meta -C–H silylation/ ortho -C–H alkylation for building silicon-containing 1,1′-biaryl-2-acetamides from 1,1′-biaryl-2-acetamides with hexamethyldisilane in the presence of NBE (Scheme -3). Interestingly, the strategy could be expanded to interannular meta -C–H silylation/ ortho -C–H alkenylation of 1,1′-biaryl-2-acetamides by the use of ONBD, instead of NBE and interannular ortho -C–H silylation of 1,1′-biaryl-2-acetamides, in the absence of NBE.…”

NBE-Controlled Palladium-Catalyzed Intermolecular Selective C–H Silylation of Boronic Acids

“…13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 154.2, 133.2, 129.7, 128.6, 47.4, 44.2, 41.7, 38.8, 37.8, 32.9, 0.7, −0.9. The spectral data were in accordance with the literature …”

“…The spectral data were in accordance with the literature. 19 Trimethyl((2R,3R)-3- (3-(trimethylsilyl)-[1,1′-biphenyl]-4-yl)bicyclo[2.2.1]heptan-2-yl)silane (2b). Purification by column chromatography on silica gel (eluent: petroleum ether) afforded 2b as a colorless oil liquid, isolated yield 61% (120 mg).…”

“…18 Subsequently, the Liang group further enriched this chemistry and developed a series of ortho-selective C−H silylation of aryl iodides (Scheme 1-a). 19 Cheng's group developed a palladium-catalyzed orthosilylation of aryl iodides/arylsilylation of oxanorbornadiene (ONBD) reaction for assembling functionalized (Z)-βsubstituted vinylsilanes (Scheme 1-b). 20 these representative approaches have a few limits, mainly focused on: (a) these methods generated the Catellani palladacycle intermediates via palladium(0)-catalyzed reactions of aryl halogens with NBE derivatives; (b) usually, it needs to add ligands in the reaction to promote the silication process; (c) the tolerance of electron-withdrawing groups was narrow in these reactions.…”