Polycationic Ligands in Gold Catalysis: Synthesis and Applications of Extremely π-Acidic Catalysts
Citations Over TimeTop 10% of 2013 papers
Abstract
Very often ligands are anionic or neutral species. Cationic ones are rare, and, when used, the positively charged groups are normally appended to the periphery of the ligand. Here, we describe a dicationic phosphine with no spacer between the phosphorus atom and the two positively charged groups. This structural feature makes its donor ability poorer than that of phosphites and only comparable to extremely toxic or pyrophoric compounds such as PF3 or P(CF3)3. By exploiting these properties, a new Au catalyst has been developed displaying a dramatically enhanced capacity to activate π-systems. This has been used to synthesize very sterically hindered and naturally occurring 4,5-disubstituted phenanthrenes. The present approach is expected to be applicable to the development and improvement of many other transition metal catalyzed transformations that benefit from extremely strong π-acceptor ligands. The mechanism of selected catalytic transformations has been explored by density functional calculations.
Related Papers
- → BN-Phenanthrenes: Synthesis, Reactivity, and Optical Properties(2019)41 cited
- → Synthesis, Properties, and Reactivity of Bis-BN Phenanthrenes: Stepwise Bromination of the Main Scaffold(2020)32 cited
- → Known or Never before Identified Phenanthrenes: Where It Is Possible to Isolate Them and Why(2022)2 cited
- → Mutagenicity of substituted phenanthrenes in Salmonella typhimurium(1983)45 cited
- → Applications of high-potential quinones. Part VII. The synthesis of steroidal phenanthrenes by double methyl migration(1971)8 cited