1,1′‐Dialkynylferrocenes as Substrates for Bidirectional Alkyne Metathesis Reaction

Abstract

In the construction of ferrocene‐based molecular wires, alkyne metathesis was investigated as an alternative to palladium‐catalyzed coupling reactions for the synthesis of alkynyl ferrocenes. With a Mortreux catalyst system [Mo(CO)6, 4‐chloro‐ or 2‐fluorophenol], (1‐propynyl)ferrocenes gave the expected homo metathesis products in moderate yields. Because the Mortreux catalyst system is not compatible with 1,1′‐dialkynylferrocenes, a nitridomolybdenum catalyst introduced by Fürstner was tested in bidirectional homo and cross‐alkyne metathesis reactions. Although the homo alkyne metathesis products were obtained in poor yields, the cross‐alkyne metathesis reactions afforded the expected products in good overall yields.

The Intramolecular Electronic Interaction Regulated by Five-membered Heterocycle Spacer

“…The ferrocene (Fc) is widely used in investigating the intramolecular electron transfers due to its redox activity and electrochemical stability, and the research on intramolecular electron transfers could provide simple and convenient for designing prospective ferrocene-containing molecular wires and conducting polymers [1][2][3][4] . Generally, two or more ferrocenyl units assembled through various conducting spacers to construct molecular models for studying intramolecular electron transfers 5 , the various kind spacers involving of the atom 6 , alkenyl 7 , alkynyl 8 and various aromatic rings 9 . When one of ferrocene unit occur electrochemical oxidize, an intramolecular donor-acceptor system is formed, the charge may be transfer to the other ferrocene units through the spacers, and the spacers' types 10 , structures 11 and chemical properties 12 can in uence the electron transfers capability.…”

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1’-diacetylenic ferrocenes

“…However, only few cases are illustrated for alkyne metathesis reactions of organometallic compounds. After some stoichiometric reactions of ruthenium and rhenium half sandwich complexes [70], several reactions have been described exploiting the reactivity of acetylenic ferrocene compounds [71–75]. For most of these conversions the Mortreux catalyst system Mo(CO) 6 /ArOH was used at elevated temperatures.…”

“…For most of these conversions the Mortreux catalyst system Mo(CO) 6 /ArOH was used at elevated temperatures. Because of the electronic properties of the ferrocene unit, polymers of acetylenic ferrocenes can be used for example as molecular wires [75].…”

Formation of alkyne-bridged ferrocenophanes using ring-closing alkyne metathesis on 1,1’-diacetylenic ferrocenes

“…After some stoichiometric reactions of ruthenium and rhenium half sandwich complexes, 70 several reactions have been described exploiting the reactivity of acetylenic ferrocene compounds. [71][72][73][74][75] For most of these conversions the Mortreux catalyst system Mo(CO)6/ArOH was used at elevated temperatures.…”

“…Because of the electronic properties of the ferrocene unit, polymers of acetylenic ferrocenes can be used for example as molecular wires. 75 Coming to ferrocenophanes, mainly carbon-bridged compounds are known. 76,77 Additionally, some complexes of mostly soft transition metals with ferrocenophane ligands could be identified.…”