The Syntheses of [3]- and [4]Ruthenocenophanes

Abstract

[3]- and [4]ruthenocenophanes as well as other ruthenocene derivatives were synthesized. The preparation of ruthenocenes in this experiment required more forced reaction conditions than those of the corresponding ferrocenes. Two cyclopentadienyl rings of these ruthenocenophanes are found to tilt mutually, and the degree of the ring-tilting of [3]ruthenocenophane is greater than that of the [4] homolog.

Influence of Cyclopentadienyl Ring‐Tilt on Electron‐Transfer Reactions: Redox‐Induced Reactivity of Strained [2] and [3]Ruthenocenophanes

“…Upon work up, species 6 was afforded as a pale yellow crystalline solid in low yield (22 %). 1 H NMR spectroscopic analysis was conducted and found to be consistent with the data reported previously for this species 53…”

“…Species 6 , which has previously been synthesized through reduction of a [3]ruthecenophan‐1‐one precursor,53 and crystallographically characterized,54 was prepared in this instance through a similar procedure to that employed for 5 11a. Thus, RuCl 2 (DMSO) 4 and Li 2 [(η 5 ‐C 5 H 4 ) 2 (CH 2 ) 3 ] were combined in THF at −78 °C.…”

“…1 H NMR spectroscopic analysis was conducted and found to be consistent with the data reported previously for this species. [53] With compound 6 in hand, we investigated its electrochemical properties. Similar to 5, CV scans of 6 (n = 0.2 V s À1 , CH 2 Cl 2 ) showed that it undergoes a one electron oxidation to afford a single electroactive product (Figure 9) although at a higher potential (by ca.…”

Synthesis, structures and reactions of some metallocene alcohols

“…We have confirmed this result and characterised 1 for the first time; the same result was also obtained using a variety of reaction temperatures and concentrations. Presumably inter-ring cyclisation to 1-keto [3]ruthenocenophane is disfavoured by the greater distance between the two rings sandwiching the larger ruthenium atom, although it has been reported that 3-ruthenocenyl-propanoate can be cyclised to this product using trifluoroacetic anhydride [53]. Attempts to perform a double Friedel-Crafts reaction (i.e., simultaneous acylation and alkylation) on ruthenocene using 3-chloropropionyl chloride and two equivalents of AlCl 3 also gave no cyclised products; in this case the diacylation product 1,1 0 -ruthenocene-1,1 0 -diylbis(3-chloropropan-1-one), 2, was obtained (Scheme 1).…”

Ruthenocenes and Osmocenes

“…Ring expansion of the ketone with CH 2 N 2 gave a mixture of [4]ruthenocenophan-l-and -2-ones, which were reduced to [4]ruthenocenophane. 172 Intramolecular dehydration of the l,l'-diol gave the corresponding 2-oxo- [3]ruthenocenophane. 137 [3]Ruthenoceneophan-l,3-dione and 3-aryl [5]ruthenocenophane-l,5-diones (aryl = Ph, Fc) have been prepared and can be used as oxidizing agents.…”