Peri Lithiation of Substituted Naphthalenes

The LDA metalation is proposed to proceed via initial amide base complexation and equilibrium formation of the 3-lithio anion 41, whose fast reaction with an in situ electrophile (TMSCl) to afford the 3-trimethylsilylated product 42 prevents its equilibration with the 2 -lithio anion 43. In the absence of TMSCl, the 3-lithio anion undergoes equilibration with 43, which cyclizes to a stable tetrahedral carbinolamine oxide which, upon hydrolysis, affords fluorenone 45. 

SCHEME 26.12 1,4-Addition of organoUthium reagents to the naphthalene x-system. 

---