C(sp³)-H結合のシリル化およびトリホウ素化，続く二酸化炭素によるカルボキシル化の開発

抄録

I herein describe iridium- and rhodium-catalyzed C(sp³)-H silylation at the benzylic position and the position adjacent to a nitrogen atom by the aid of a nitrogen directing group. The silylated products could be further carboxylated with carbon dioxide (1 atm of CO₂) under fluoride-mediated conditions, giving carboxylic acid derivatives in high yields. It should be a formal carboxylation of C(sp³)-H bonds triggered by metal-catalyzed C-H silylation. We also developed a novel triborylation reaction of terminal C(sp³)-H bonds (2-ethylpyridine derivatives). The obtained triborylated compounds were successfully converted into carboxylic acids by using either CsF under a CO₂ atmosphere or H₂O₂ in the presence of TsOH·H₂O.