Rhodium-Catalyzed <i>Trans</i>-Bis-Silylation Reactions of 2-Ethynyl-3-pentamethyldisilanylpyridines

Abstract

Rhodium-catalyzed reactions of 2-ethynyl-3-pentamethyldisilanylpyridine derivatives (1 and 2) are reported. The reactions of compounds 1 and 2 in the presence of catalytic amounts of rhodium complexes at 110 °C gave the corresponding pyridine-fused siloles (3) and (4) through intramolecular trans-bis-silylation cyclization. The reaction of 2-bromo-3-(1,1,2,2,2-pentamethyldisilanyl)pyridine with 3-phenyl-1-propyne in the presence of PdCl2(PPh3)2-CuI catalysts afforded 1:2 bis-silylation adduct 6. DFT calculations were also performed to understand the reaction mechanism for the production of compound 3 from compound 1.

Keywords

• rhodium-catalyzed reaction
• <i>trans</i>-bis-silylation
• silole
• DFT calculation
• 2-ethynyl-3-pentamethyldisilanylpyridine
• cyclic silicon compound