Functionalization of 3-Iodo-N,N-Diisopropylferrocene-Carboxamide, a Pivotal Substrate to Open the Chemical Space to 1,3-Disubstituted Ferrocenes

William Erb (1) , Lingaswamy Kadari (1, 2) , Khadega Al-Mekhlafi (1) , Thierry Roisnel (1) , Vincent Dorcet (1) , Palakodety Radha Krishna (2) , Florence Mongin (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 IICT - CSIR Indian Institute of Chemical Technology [Hyderabad]

From 2-iodo-N,N-diisopropylferrocenecarboxamide, the halogen 'dance' reaction was applied to deliver gram quantities of the 3-iodo isomer. The latter was successfully functionalized by Ullmann-type and Suzuki-Miyaura cross-couplings to build C-O and C-C bonds, respectively. Lithium/iodine exchange-electro-philic trapping sequences were also implemented to provide ferrocenes bearing valuable functional groups. Borane-mediated carboxamide reduction was next studied on selected substrates to deliver the corresponding amino derivatives in moderate to excellent yields. One of them, 1-(N,N-diisopropylaminomethyl)-3-iodoferrocene, was used as a substrate to access various iodoferrocene derivatives. Not only this work constitutes a general entry into the world of 1,3-disubstituted ferrocenes, but it also extends the chemical space available around this original scaffold.

Keywords: Suzuki-Miyaura cross-coupling; Ullmann-type cross-coupling; Halogen migration; Ferrocene; Carboxamide

Domains: Chemical Sciences; Coordination chemistry

William Erb, Lingaswamy Kadari, Khadega Al-Mekhlafi, Thierry Roisnel, Vincent Dorcet, et al.. Functionalization of 3-Iodo-N,N-Diisopropylferrocene-Carboxamide, a Pivotal Substrate to Open the Chemical Space to 1,3-Disubstituted Ferrocenes. Advanced Synthesis and Catalysis, 2020, 362 (4), pp.832-850. ⟨10.1002/adsc.201901393⟩. ⟨hal-02438541⟩