Daniel Catheline

The use of ferrocene in organometallic synthesis: A two-step preparation of cyclopentadienyliron acetonitrile and phosphine cations via photolysis of cyclopentadienyliron tricarbonyl or arene cations

Abstract UV photolysis of [CpFe II (CO) 3 ] + PF6 6 − (I) or [CpFe II (η 6 -toluene)] + PF 6 − − (II) in CH 3 CN in the presence of 1 mole of a ligand L gives the new air sensitive, red complexes [CpFe II (NCCH 3 ) 2 L] + PF 6 − (III, L = PPh 3 ; IV; L = CO; VIII, L = cyclohexene; IX, L = dimethylthiophene) and the known air stable complex [CpFe II (PMe 3 ) 2 (NCMe)] + PF 6 − (V). The last product is also obtained by photolysis in the presence of 2 or 3 moles of PMe 3 . In the presence of dppe, the known complex [CpFe II (dppe)(NCCH 3 )] + (XI) is obtained. Complex III reacts with CO under mild conditions to give the known complex [CpFe(NCCH 3 )(PPh 3 )CO] + PF 6 − (X). UV photolysis of I in CH 3 CN in the presence of 1-phenyl-3,4-dimethylphosphole (P) gives [CpFe II P 3 ] + PF 6 − (XII); UV photolysis of II in CH 2 Cl 2 in the presence of 3 moles of PMe 3 or I mole of tripod (CH 3 C(CH 2 Ph 2 ) 3 ) provides an easy synthesis of the known complexes [CpFe II (PMe 3 ) 3 ] + PF 6 − (VII) or [CpFe II η 3 -tripod] + PF 6 t- (XIII). Since I and II are easily accessible from ferrocene, these photolytic syntheses provide access to a wide range of piano-stool cyclopentadienyliron(II) cations in a 2-step process from ferrocene.

Bis- and tris-acetonitrile complexes of iron(II)

Zusammenfassung Photolysis of [CpFe(CO) 3 ] + PF 6 − in CH 3 CN in the presence of 2-, 4- or 6-electorn ligands gives [CpFeL n (NCCH 3 ) 3− n ] + PF 6 − ( n = 1: L = CO, PPh 3 , cyclohexene, dimethylthiophene; n = 2: L 2 = dppe or n = 3: L 3 = cyclooctatetraene, or three phospholes), whereas in the absence of added ligand a thermally stable purple tris(acetonitrile) complex is isolable only using permethylated Cp. The synthetic potential of the acetonitrile complexes is illustrated by the stepwise replacement of the acetonitrile ligands.

Insertion of CS2 and CSe2 into metal—amido bonds. Mono- versus bi-dentate dithiocarbamates formed by reactions of CS2 + NHR2 with {CpMo(CO)n}2 (M Fe, n 2; m Mo, n 3)

Abstract The reaction of Cp2Fe2(CO)4 with NHEt2 and CS2 gives the monodentate dithiocarbamate CpFe(CO)2-η1-SC(S)NEt2 (Ia), whereas the same reaction with CP2Mo2(CO)6 gives the chelate CPMo(CO)2-η2-S2CNEt2 (II). New complexes of amines CpFe(CO)2(NHR2)+PF6- (III, R ue5fb Me, Et, SiMe3) have been synthesized by treating CpFe(CO)2Cl with NHR2. They do not react with CS2 and give only [CpFe(CO)2]2 upon refluxing with bases such as t-BuOK or NEt(i-Pr)2, but concerted CS2 insertion in the presence of a base immediately gives I at 20°C. This clean route is used to synthesize the monodentate diselenocarbamate CpFe(CO)2-η1-SeC(Se)NMe2 (IV) by reaction of CSe2 with III (R ue5fb Me) in the presence of t-BuOK. Whereas the known reaction of CpFe(CO)2Cl with Na+S2CNMe2− gives Ib (R ue5fb Me), the analogous reaction of C5Me5Me(CO)2Br gives specifically the thermally stable chelate C5Me5Fe(CO)-η2-S2CNMe2 (Vb′).

Synthesis and characterization of C5(CH3)5Fe(CO)3+ PF6− and C5(CH3)5Fe(CO)2− K+☆

Abstract C 5 (CH 3 ) 5 Fe(CO) 3 + PF 6 − is obtained in 67% yield by reaction of C 5 (CH 3 ) 5 Fe(CO) 2 Br with AlCl 3 at 60°C under a 40-atm CO pressure. {C 5 (CH 3 ) 5 Fe(CO) 2 } 2 does not react with Na/Hg, but a 2 h reduction on K mirror in THF at 20°C provides C 5 (CH 3 ) 5 Fe(CO) 2 − K + , which can be alkylated by CH 3 I to give C 5 (CH 3 ) 5 Fe(CO) 2 CH 3 in 80% overall yield.

Oxidative cleavage of the FeFe bond in [C5Me5Fe(CO)2]2 using ferrocinium ion: A facile route to the synthetically useful complexes [C5Me5Fe(CO)2(solvent)]+

Abstract Complexes of the type {Fp′(solvent)} + PF 6 − , 3a–3d , (Fp′ = (η -C 5 Me 5 )Fe(CO) 2 , solvent = THF, CH 3 COCH 3 , CH 3 CN, or pyridine) are conveniently prepared by the reaction between Fp′ 2 and Cp 2 Fe + PF 6 (Cp = η 5 -C 5 H 5 ) in the solvent under ambient conditions. The complexes {Fp′L} + PF 6 − , 3e–3g , (L = CO, PPh 3 , P(OPh) 3 ) are readily prepared from {Fp′THF} + . Fp′H is formed by treatment of 3a with NaBH 4 . Fp′SC(S)NMe 2 can be prepared from 3a or 3e and NaSC(S)NMe 2 .

The mono-, bis-, and tris-trimethylphosphineiron(II) complexes {(η5-C5Me5)Fe(PMe3)x(CO)y(NCMe)z}+PF6− (x + y + z = 3)

Abstract Syntheses are reported for the six trimethylphosphineiron complexes {(η5-C5Me5)Fe(PMe3)x(CO)y(NCMe)z}+PF6− (x + y+ z = 3).

Reactivity of the unco-ordinated sulphur atom in monodentate dithiocarbamates: formation of the heterometallocycles FeS2C2 by reaction of KCN with [(η5-C5H5)Fe(CO)2{η1-SC(S)NR2}] and X-ray crystal structure of the benzoylaion porduct [η5-C5H5)Fe(CO){SC(NEt2)(SCNCOPh)}]

The complexes [(η5-C5H5)Fe(CO)2{η1-SC(S)NR2}](R = Me or Et) react with KCN in methanol to give the five-membered-metallocycles K[(η5-C5H5)[graphic omitted]N)}](2) which can be acylated by PhCOCl giving [(η5–C5H5)[graphic omitted]NCOPh)}](3) which had been characterized by X-ray diffraction for the complex with R = Et.