Preparation of Diethylcyanamide and Cyanoguanidine Complexes of Iridium

Diethylcyanamide [IrCl(η5‐C5Me5)(N≡CNEt2){P(OR)3}]BPh4 (1) and cyanoguanidine complexes [IrCl(η5‐C5Me5){N≡CN(H)C(NH2)=NH}{P(OR)3}]BPh4 (2) were prepared by allowing chloro compounds [IrCl2(η5‐C5Me5){P(OR)3}] to react with an excess of cyanamide or cyanoguanidine, respectively. Alternatively, complexes 2 were prepared by reacting [IrCl2(η5‐C5Me5){P(OR)3}] with an excess of cyanamide N≡CNH2. Bis(diethylcyanamide) [Ir(η5‐C5Me5) (N≡CNEt2)2{P(OR)3}](BPh4)2 (3) and bis(cyanoguanidine) derivatives [Ir(η5‐C5Me5){N≡CN=C(NH2)2}2{P(OR)3}](BPh4)2 (4) were also prepared by treating dichloro precursors [IrCl2(η5‐C5Me5){P(OR)3}] first with two equivalents of AgOTf and then with an excess of diethylcyanamide or cyanoguanidine, respectively. The compounds were characterised spectroscopically (IR and NMR) and by X‐ray crystal structure determination of [Ir(η5‐C5Me5)(N≡CNEt2)2{P(OMe)3}](BPh4)2

Pentamethylcyclopentadienyl osmium complexes that contain diazoalkane, dioxygen and allenylidene ligands: preparation and reactivity

Diazoalkane complexes [Os(η5-C5Me5)(N2CAr1Ar2)(PPh3){P(OR)3}]BPh4 (1, 2) [R = Me (1), Et (2); Ar1 = Ar2 = Ph (a); Ar1 = Ph, Ar2 = p-tolyl (b); Ar1Ar2 = C12H8 (fluorenyl) (c)] were prepared by reacting bromo-compounds OsBr(η5-C5Me5)(PPh3){P(OR)3} with an excess of diazoalkane in ethanol. The treatment of diazoalkane complexes 1 and 2 with acetylene under mild conditions (1 atm, RT) led to dipolar (3 + 2) cycloaddition affording 3H-pyrazole derivatives [Os(η5-C5Me5)(η1-[upper bond 1 start]N[double bond, length as m-dash]NC(C12H8)CH[double bond, length as m-dash]C[upper bond 1 end]H)(PPh3){P(OR)3}]BPh4 (6, 7) [R = Me (6), Et (7)] whereas reactions with terminal alkynes R1C[triple bond, length as m-dash]CH (R1 = Ph, p-tolyl, COOMe) gave vinylidene derivatives [Os(η5-C5Me5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)R1}(PPh3){P(OR)3}]BPh4 (8b–d, 9b–d) [R = Me (8), Et (9); R1 = Ph (b), p-tolyl (c), COOMe (d)]. Exposure to air of dichloromethane solutions of complexes 1 and 2 produced dioxygen derivatives [Os(η5-C5Me5)(η2-O2)(PPh3){P(OR)3}]BPh4 (10, 11) [R = Me (10), Et (11)]. Allenylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]CR1R2 (12–14) [R1 = R2 = Ph (12, 13); R1 = Ph, R2 = Me (14)], vinylvinylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C(H)C(Ph)[double bond, length as m-dash]CH2 (15) and 3-hydroxyvinylidene [Os][double bond, length as m-dash]C[double bond, length as m-dash]C(H)C(H)R2(OH) (16, 17) [R2 = Ph (16), H (17)] derivatives were also prepared. The vinylidene complex [Os(η5-C5Me5)([double bond, length as m-dash]C[double bond, length as m-dash]CH2)(PPh3){P(OMe)3}]BPh4 (8a) reacted with PPh3 to afford the alkenylphosphonium derivative [Os(η5-C5Me5){η1-C(H)[double bond, length as m-dash]C(H)PPh3}(PPh3){P(OMe)3}]BPh4 (18) whereas vinylidene complexes 8 and 9 reacted with water leading to the hydrolysis of the alkyne and the formation of carbonyl complexes [Os(η5-C5Me5)(CO)(PPh3){P(OR)3}]BPh4 (19, 20). The complexes were characterised by spectroscopic data (IR and NMR) and by X-ray crystal structure determination of [Os(η5-C5Me5){[double bond, length as m-dash]C[double bond, length as m-dash]C(H)p-tolyl}(PPh3){P(OEt)3}]BPh4 (9c), [Os(η5-C5Me5)(η2-O2)(PPh3){P(OMe)3}]BPh4 (10) and [Os(η5-C5Me5)(CO)(PPh3){P(OMe)3}]BPh4 (19)

Preparation of pyranylidene complexes of ruthenium

Dimerization of alkylpropiolate on the half-sandwich fragment [Ru(η5-C5H5)(PPh3){P(OMe)3}]+ affords pyranylidene derivatives

Trichlorostannyl complexes of Ruthenium(II): Synthesis, structure, reactivity and computational studies

Trichlorostannyl complexes [Ru(SnCl3) (Cp')L] (2a-c) were prepared by treatment of optically active half-sandwich chlorocomplexes [RuCl(Cp')L] (1a-c) with an excess of SnCl2.2H2O in ethanol. Treatment of trichlorostannyl complexes 2a-c with NaBH4 afforded trihydridostannyl derivatives [Ru(SnH3) (Cp')L] (3a-c) in moderated yields. Treatment of 2a-c with MgBrMe gave the trimethylstannyl complexes Ru(SnMe3) (Cp')L (4a-c). Alkynylstannyl derivatives [Ru{Sn(C≡CPh)3}(Cp')L] (5a-c) were prepared by treatment of trichlorostannyl compounds 2a-c with an excess of LiC≡CPh in thf. All the complexes present optical activity. The complexes were characterized spectroscopically and by X-ray crystal structure determination of [RuCl(η5-C5Me5)L] (1b), [Ru(SnCl3) (η5-C5Me5)L] (2b), and [Ru(SnCl3) (η5-C9H7)L] (2c). The influence of different ligands on the RuP interaction in several complexes 1a-c, 2a-c and 3a-c was evaluated by DFT calculations. These calculations indicate that [SnCl3]- has a stronger stabilization effect than [Cl]- and the same occurs between C9H7 and C5Me5. These relative stabilities combined with the distortion energies of the fragments produce a stabilizing effect in the RuP bonds of complex 2c that is twice as strong as in the 1b complex

Diazoalkane complexes of ruthenium with tris(pyrazolyl)borate and bis(pyrazolyl)acetate ligands

Diazoalkane complexes [Ru(Tp)(N(2)CAr1Ar2)(PPh3)L]BPh4 (1 and 2) [Tp = tris(pyrazolyl) borate; L = P(OMe)(3), P(OEt)(3); Ar1 = Ar2 = Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8] were prepared by allowing chloro-compounds RuCl(Tp)(PPh3) L to react with diazoalkane in the presence of NaBPh4. Acrylonitrile CH2=C(H) CN reacts with diazoalkane complexes to give 3H-pyrazole derivatives [Ru(Tp){N=NC(Ar1Ar2)CH(CN)CH2}(PPh3){P(OMe)(3)}]BPh4 and [Ru(Tp){N=NC(Ar1Ar2)CH2C(H)CN}(PPh3)-{P(OMe)(3)}]BPh4 (3). Diazoalkane complexes [Ru(bpza)(N(2)CAr1Ar2)(PPh3)(2)]BPh4 (4) [bpza = bis(pyrazolyl)-acetate] were also prepared. All complexes were characterised by IR and NMR spectroscopy and X-ray crystal structure determination of [Ru(Tp){N2C(Ph)(p-tolyl)}(PP(h)3){P(OMe)(3)}]BPh4 (1b). The differences exhibited by [Ru(Tp){N2C(Ph)(p-tolyl)}(PPh3){P(OMe)(3)}](+) and [Ru(Cp){N2C(Ph)(p-tolyl)}(PPh3){P(OMe)(3)}](+), as regards coordination of the diazoalkane ligand and reactivity towards alkenes, were explained on the basis of a comparative DFT study

Preparation and reactivity of diazoalkane complexes of ruthenium stabilised by an indenyl ligand

Diazoalkane complexes [Ru(η5-C9H7)(N2CAr1Ar2)(PPh3)L]BPh4 (1-3) [L = PPh3, P(OMe)3, P(OEt)3; Ar1 = Ar2 = Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8 fluorenyl] were prepared by allowing chloro-complexes [RuCl(η5-C9H7)(PPh3)L] to react with an excess of diazoalkane in ethanol. Complexes 1-3 reacted with ethylene CH2=CH2 (1 atm) and maleic anhydride [ma, CH=CHCO(O)CO] to afford η2-alkene complexes [Ru(η5-C9H7)(η2-CH2=CH2)(PPh3)L]BPh4 (4, 5) and [Ru(η5-C9H7){η2-CH=CHCO(O)CO}(PPh3)L]BPh4 (7). Further, complexes 1-3 underwent cycloaddition with acrylonitrile CH2=C(H)CN, giving 1H-pyrazoline derivatives [Ru(η5-C9H7){η1-N=C(CN)CH2C(Ar1Ar2)NH}(PPh3)L]BPh4 (6). Treatment of diazoalkane complexes 1-3 with acetylene CH≡CH under mild conditions (1 atm, room temperature) led to dipolar cycloaddition, affording 3H-pyrazole complexes [Ru(η5-C9H7)-{η1-N=NC(Ar1Ar2)CH=CH}(PPh3)L]BPh4 (8), whereas reaction with terminal alkynes RC≡CH (R = Ph, p-tolyl, But) gave vinylidene derivatives [Ru(η5-C9H7){=C=C(H)R}(PPh3)L]BPh4 (9). The latter reacted with nucleophiles such as amines and alcohols to give amino- and alkoxy-carbene derivatives [Ru(η5-C9H7){=C(NHPrn)(CH2Ph)}(PPh3)L]BPh4 (11) and [Ru(η5-C9H7){=C(CH3)(OEt)}(PPh3)L]BPh4 (10), respectively. In addition, complexes 9 reacted with phenylhydrazine to afford nitrile derivatives [Ru(η5-C9H7)(NC≡CH2R)(PPh3)L]BPh4 (12) and phenylamine, whereas the reaction with water led to hydrolysis of the alkyne and formation of carbonyl complexes [Ru(η5-C9H7)(CO)(PPh3)L]BPh4 (13). Lastly, treatment of vinylidene complexes 9 with the phosphines PPh3 and P(OMe)3 afforded alkenylphosphonium derivatives [Ru(η5-C9H7){C(H)=C(R)PPh3}(PPh3)L]BPh4 (14) and [Ru(η5-C9H7){C(R)=C(H)P(OMe)3}(PPh3)L]BPh4 (15), respectively. Compound [Ru(η5-C9H7){C(H)=C(H)PPh3}(PPh3)L]BPh4 (16) was also prepared. The complexes were characterised by spectroscopy (IR and NMR) and X-ray crystal structure determinations of [Ru(η5-C9H7){N2C(C12H8)}(PPh3){P(OEt)3}]BPh4 (3c), [Ru(η5-C9H7){=C=C(H)Ph}(PPh3){P(OEt)3}]BPh4 (9d) and [Ru(η5-C9H7){C(H)=C(Ph)PPh3}(PPh3){P(OEt)3}]BPh4 (14d).Diazoalkane complexes [Ru(eta(5)-C9H7)(N(2)CAr1Ar2)(PPh3)L]BPh4 (1-3) [L = PPh3, P(OMe)(3), P(OEt)(3); Ar1 = Ar2 = Ph; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8 fluorenyl] were prepared by allowing chloro-complexes [RuCl(eta(5)-C9H7)(PPh3)L] to react with an excess of diazoalkane in ethanol. Complexes 1-3 reacted with ethylene CH2-CH2 (1 atm) and maleic anhydride [ma, CH-CHCO(O)CO] to afford eta(2)-alkene complexes [Ru(eta(5)-C9H7)(eta(2)-CH2=CH2)(PPh3)L]BPh4 (4, 5) and [Ru(eta(5)-C9H7){eta(2)-CH=CHCO(O)CO}(PPh3)L] BPh4 (7). Further, complexes 1-3 underwent cycloaddition with acrylonitrile CH2=C(H)CN, giving 1H-pyrazoline derivatives [Ru(eta(5)-C9H7){eta(1)-N=C(CN)CH2C(Ar1Ar2)NH}(PPh3)L]BPh4 (6). Treatment of diazoalkane complexes 1-3 with acetylene CH equivalent to CH under mild conditions (1 atm, room temperature) led to dipolar cycloaddition, affording 3H-pyrazole complexes [Ru(eta(5)-C9H7)-{eta(1)-N=NC(Ar1Ar2) CH=CH}(PPh3)L]BPh4 (8), whereas reaction with terminal alkynes RC equivalent to CH (R = Ph, p-tolyl, Bu-t) gave vinylidene derivatives [Ru(eta(5)-C9H7){=C=C(H) R}(PPh3)L]BPh4 (9). The latter reacted with nucleophiles such as amines and alcohols to give amino- and alkoxy-carbene derivatives [Ru(eta(5)-C9H7){=C(NHPrn)(CH2Ph)}(PPh3)L]BPh4 (11) and [Ru(eta(5)-C9H7){=C(CH3)(OEt)}(PPh3)L] BPh4 (10), respectively. In addition, complexes 9 reacted with phenylhydrazine to afford nitrile derivatives [Ru(eta(5)-C9H7)(N equivalent to CCH2R)(PPh3)L]BPh4 (12) and phenylamine, whereas the reaction with water led to hydrolysis of the alkyne and formation of carbonyl complexes [Ru(eta(5)-C9H7)(CO)(PPh3)L]BPh4 (13). Lastly, treatment of vinylidene complexes 9 with the phosphines PPh3 and P(OMe)(3) afforded alkenylphosphonium derivatives [Ru(eta(5)-C9H7){C(H) =C(R)PPh3}(PPh3)L]BPh4 (14) and [Ru(eta(5)-C9H7){C(R)=C(H) P(OMe)(3)}(PPh3)L]BPh4 (15), respectively. Compound [Ru(eta(5)-C9H7){C(H)=C(H)PPh3}(PPh3)L]BPh4 (16) was also prepared. The complexes were characterised by spectroscopy (IR and NMR) and X-ray crystal structure determinations of [Ru(eta(5)-C9H7){N2C(C12H8)}(PPh3){P(OEt)(3)}]BPh4 (3c), [Ru(eta(5)-C9H7){=C=C(H) Ph}(PPh3){P(OEt)(3)}] BPh4 (9d) and [Ru(eta(5)-C9H7){C(H)=C(Ph) PPh3}(PPh3){P(OEt)(3)}]BPh4 (14d)