Synthetic Studies for the 1,3‐Iterative Organoiron Approach to the Synthesis of Siculinine: Efficient Arylation Using a Diarylcuprate Reagent

Disubstituted (cyclohexadienyl)iron(1+) complex 2b is prepared by an improved route that starts from 1,2‐dimethoxycyclohexa‐1,4‐diene 3 . In five steps, the synthesis of 2b is achieved by complexation with Fe(CO) 5 , hydride abstraction, hydrolysis, addition of EtO 2 CCH 2 ZrBr, and reaction with HBF 4 . In the presence of dimethyl sulfide, the reaction of 2b with 2‐[CH 2 N(CH 2 CH=CH 2 ) 2 ]‐functionalized diarylcuprate reagent 7 gave the 5α‐arylcyclohexadiene complex 1b in 88 % yield. A DFT study compared diarylzinc and diarylcuprate reagents containing chelating CH 2 NMe 2 substituents.