(Cyclopentadienone)iron Shvo Complexes: Synthesis and Applications to Hydrogen Transfer Reactions

Abstract

A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. For more information, please contact the WRAP ABSTRACT A series of (cyclopendienone)irontricarbonyl complexes were prepared using an intramolecular cyclisation strategy. These were applied to the catalysis of the oxidation of alcohols to aldehydes and ketones. When paraformaldehyde was used as the hydrogen acceptor, formate esters were obtained as co-products and, in several cases, the major products.

Microwave-assisted synthesis of cyclopentadienone iron tricarbonyl complexes: molecular structures of [{η4-C4R2C(O)C4H8}Fe(CO)3] (R = Ph, 2,4-F2C6H3, 4-MeOC6H4) and attempts to prepare Fe(II) hydroxycyclopentadienyl–hydride complexes

“…Over the past 20 years, few developments have been made to this procedure, with Wills and co-workers recently reporting the use of similar conditions for the low-moderate-yield synthesis of some related complexes [17], although a CO pressure was not required. We have been interested in using such complexes as catalysts for a range of organic transformations but considered the harsh reaction conditions required for their synthesis to be detrimental to our ability to readily fine-tune the nature of the substituents on both the cyclopentadienone ring and also the saturated backbone.…”

“…Iron catalysts are particularly attractive since not only is this metal abundant but it is also biocompatible which limits the concerns of toxicity and environmental impact. Consequently, the development of homogeneous iron catalysts has become a topic of intense interest with some significant breakthroughs being made over the past few years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. An obvious place to start with respect to the development of iron catalysts is the replacement of its heavier congeners ruthenium and osmium.…”

“…The synthesis of cyclopentadienone complexes of this type is typically achieved via the [2 + 2 + 1] cycloaddition of 1,6-hexadiynes and iron carbonyls [14][15][16][17][46][47][48][49][50][51][52][53][54]. Such processes require high temperatures and long reaction times and generally provide the desired cyclopentadienone complexes in only low-to-moderate yields.…”

Cyclopentadienon‐Eisenkomplexe: Entdeckung, Eigenschaften und katalytische Reaktivität

“…[28] Erwähnenswert ist, dass Katalysatoren mit Phenyl-anstelle der Trimethylsilylgruppen am Dienon oder mit einem fünfgliedrigen Ring anstelle des Cyclohexans eine niedrigere katalytische Aktivität als Fe6 aufwiesen. [29] Die Umsetzung wurde bei 90 8C in einem geschlossenen Gefäß durchgeführt (Schema 15 b).…”

“…[25] Wills und Mitarbeiter modifizierten die Struktur des Cyclopentadienonmotivs und erhielten die Komplexe Fe16, um deren Aktivität in einer verwandten Wasserstofftransferoxidation zu untersuchen (Schema 16 a). [29]…”