Nitrile Adducts Research Articles

A Novel Reactivity of Phosphanylalumane (>P-Al

The reversible addition of olefins to a phosphanylalumane, P-Al single-bond species, was investigated. The P-Al bond added to ethylene and relatively small terminal alkenes (propylene and hex-1-ene) at room temperature to give the corresponding alkene adducts. Heating the terminal alkene adducts released the corresponding alkenes and regenerated the P-Al bond, but no release of ethylene was observed even under vacuum conditions. The reactivity of ethylene adduct as a new saturated C2 vicinal P/Al-based FLP was also investigated. The ethylene adduct was found to undergo complexation with nitriles to give the corresponding nitrile adducts to the Al center, which retained the ethylene tether as in the case of the corresponding P/B-based FLP. However, the reactivity of ethylene toward CO2 and benzaldehyde differed from that of the P/B system giving the corresponding adducts.

Silver-Catalyzed Selective Multicomponent Coupling Reactions of Arynes with Nitriles and Isonitriles.

Pathway selective aryne-based novel multicomponent coupling reactions with isonitriles and nitriles are described. Crucial to these reactions is the formation of a silver-aryne complex, which shows differential reactivity toward isonitriles and nitriles to form two different forms of ortho-nitrilium organosilver arene species. Interception of the nitrilium of an aryne-isonitrile adduct with another isonitrile leads to the formation of benzocyclobutene-1,2-diimines, whereas the nitrilium of an aryne-nitrile adduct renders selective formation of 3H-indol-3-imines or 3-iminoindolin-2-ol depending on the structure of the nitrile employed.

The addition of nitriles to tetramesityldisilene: a comparison of the reactivity between surface and molecular disilenes.

The addition of acetonitrile, propionitrile, and phenylacetonitrile to tetramesityldisilene (Mes2 Si=SiMes2 ) was examined. In general, 1,2,3-azadisiletines and the tautomeric enamines were formed, although a ketenimine was formed as the major product in the addition of phenylacetonitrile to the disilene. In the presence of LiCl, the mode of addition changed for both acetonitrile and propionitrile: insertion into the α-CH bond of acetonitrile and/or formation of the formal HCN adduct was observed. Preliminary investigations of the reactivity of the nitrile adducts are also reported. A comparison between the reactivity of nitriles with Mes2 Si=SiMes2 and the Si(100)-2×1 surface was made both in terms of the types of adducts formed and their reactivity. Some insights into the surface chemistry are offered.

Lutidine-Derived Ru-CNC Hydrogenation Pincer Catalysts with Versatile Coordination Properties

Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC–pincer complexes (Ru-CNC’s) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give ketimino compounds 4–6. Nitrile adduct 4 shows reactivity toward strong bases to yield dearomatized complex 7, which heterolytically activates H2 to form the bis-hydrido complex 8. Finally, these Ru-CNC’s are active in catalytic hydrogenation of CO2 to formate salts, and unlike the phosphine-containing Ru-PNP counterpart, they also catalyze the selective hydrogenation of esters to alcohols.

New synthesis of multisubstituted cyanocyclopropanes by the intramolecular SN2 alkylation and 1,3-CC insertion reaction of magnesium carbenoids as the key reactions

Addition reaction of 1-chlorovinyl p-tolyl sulfoxides derived from ketones and aldehydes with lithium α-cyano carbanions gave nitrile adducts in high to quantitative yields. Treatment of the nitrile adducts derived from acetonitrile with excess i-PrMgCl in THF resulted in the formation of cyanocyclopropanes via the intramolecular SN2 alkylation of the generated magnesium carbenoids. The intermediate of this reaction was proved to be a cyclopropylmagnesium chloride and was reactive with electrophiles to give multisubstituted cyanocyclopropanes. On the other hand, the reaction of the nitrile adducts derived from arylacetonitriles with i-PrMgCl resulted in the formation of 2-arylcyanocyclopropanes by the 1,3-carbon–carbon (1,3-CC) insertion reaction of the generated magnesium carbenoid intermediates. This reaction was found to proceed in a highly stereospecific manner. The key reactions, intramolecular SN2 alkylation and 1,3-CC insertion reaction of the magnesium carbenoids, are the first examples for the reaction of the magnesium carbenoids bearing a nitrile functional group.

Benzonitrile Adducts of Terminal Diarylphosphido Complexes: Preparative Sources of “Ru═PR2”

Dehydrohalogenation of secondary diarylphosphine ruthenium complexes in the presence of benzonitrile yields stable, isolable nitrile adducts of the formula [Ru(η5-indenyl)(PAr2)(NCPh)(PPh3)], in which the terminal phosphido ligand is pyramidal at P and contains a stereochemically active lone pair. Unlike the analogous carbonyl adducts [Ru(η5-indenyl)(PAr2)(CO)(PPh3)], these benzonitrile complexes behave as masked sources of the highly reactive planar phosphido complexes [Ru(η5-indenyl)(PAr2)(PPh3)], which contain a Ru═PAr2 π bond. This is illustrated by the addition (or cycloaddition) reactions of the benzonitrile adducts with dihydrogen, methyl iodide, and 1-hexene, as well as their thermal decomposition via orthometalation of the PPh3 ligand. Enthalpies of CO vs NCPh dissociation from the [Ru(η5-indenyl)(PR2)(PPh3)] fragments (R = alkyl, aryl) have been calculated, as has the trajectory of addition of H2 to the model planar phosphido complex [Ru(η5-indenyl)(PMe2)(PMe3)]. The latter study shows the inter...

Sigma bond metathesis with pentamethylcyclopentadienyl ligands in sterically crowded (C5Me5)3M complexes

To further explore the reactivity of the (C(5)Me(5))(-) ligand in the sterically crowded (C(5)Me(5))(3)M complexes, reactions with PhEEPh (E = S, Se, Te) have been examined. With M = La, Pr, Nd, Sm, and Y, PhSSPh reacts to form the expected reduction products, [(C(5)Me(5))(2)M(SPh)](2), but the major organic byproduct is not the sterically induced reduction product, (C(5)Me(5))(2). Instead, the sigma bond metathesis product, C(5)Me(5)SPh, is the major byproduct. In contrast, reactions with (C(5)Me(5))(3)Ce and (C(5)Me(5))(3)U gave a mixture of C(5)Me(5)SPh and (C(5)Me(5))(2) as byproducts. PhSSPh reactions with the lanthanide nitrile adducts, (C(5)Me(5))(3)Ln(NCCMe(3))(2) (Ln = La, Ce) and (C(5)Me(5))(3)Nd(NCCMe(3)), formed [(C(5)Me(5))(2)Ln(SPh)(NCCMe(3))](2) and only C(5)Me(5)SPh as the byproduct. PhSeSePh reactions paralleled the PhSSPh results, but reactions of PhTeTePh with (C(5)Me(5))(3)La, (C(5)Me(5))(3)Sm, and (C(5)Me(5))(3)La(NCCMe(3))(2) gave only (C(5)Me(5))(2) as a byproduct.

An 11B NMR spectroscopy investigation of the mechanism of the reduction of nitriles by BH 3 · SMe 2

A kinetic and mechanistic investigation of the reduction of acrylonitrile, propionitrile and benzonitrile by BH 3 · SMe 2 in CH 2Cl 2 has been conducted using 11B NMR spectroscopy. No reduction of propionitrile and benzonitrile was observed at 25 °C, while the reduction of acrylonitrile was monitored to the vinyliminoborane. The reaction exhibited simple second-order kinetics of the form k obs = k 2 ′ [ acrylonitrile ] , with the dissociation of the dimethyl sulfide from borane playing a key role in controlling the reduction process. The activation parameters (Δ S ≠ and Δ H ≠) for the reaction of BH 3 · SMe 2 with acrylonitrile were found to be −71 ± 10 J K −1 mol −1 and 58 ± 3 kJ mol −1, respectively. The B3LYP/6-31G ∗ results for charge distribution and transfer during the reaction show a reversal of charge in the borane–nitrile adduct for the atoms that make up the borane and the nitrogen and carbon atoms in the nitrile. The activation barriers for the reduction of acrylonitrile were found to be 6–8 kJ mol −1 lower than those of hydrogen cyanide, propionitrile and benzonitrile, with its product iminoborane being 30–130 kJ mol −1 more stable than those of the other nitriles.

Synthesis of trisubstituted alkenes by reductive dehydroxylation of Baylis–Hillman adducts using polymethylhydrosiloxane (PMHS) and catalytic B(C 6F 5) 3

B(C 6F 5) 3 as a catalyst and polymethylhydrosiloxane as a hydride source have been employed for the reductive dehydroxylation of Baylis–Hillman adducts wherein the hydride adds in an S N2′ manner onto the unactivated allyl alcohol moiety with concomitant elimination of the hydroxy group along with double bond migration. The products formed were found to be E in the case of ester adducts and Z in the case of nitrile adducts.

Electronic tuning of β-diketiminate ligands with fluorinated substituents: effects on the O2-reactivity of mononuclear Cu(i) complexes

Copper(i) complexes with the beta-diketiminate ligands HC{C(R)N(Dipp)}{C(R')N(Dipp)}(-) (Dipp = C(6)H(3)(i)Pr(2-)2,6; L(1), R = CF(3), R' = CH(3); L(2), R = R' = CF(3)) have been isolated and fully characterized. On the basis of X-ray structural comparisons with the previously reported complex LCu(CH(3)CN) (L = HC{C(CH(3))N(Dipp)}(2)(-)), the ligand environments at the copper centers in the analogous nitrile adducts with L(1) and L(2) impose similar steric demands. L(1)Cu(CH(3)CN) reacts instantaneously at low temperature with O(2) to form a thermally-unstable intermediate with an isotope-sensitive vibration at 977 cm(-1) (928 cm(-1) with (18)O(2)), in accord with the peroxo O-O stretch associated with side-on coordination for LCu(O(2)). However, L(2)Cu(CH(3)CN) is unreactive toward O(2) even at room temperature. Evaluation of the redox potentials of the nitrile adducts and the CO stretching frequencies of the carbon monoxide adducts revealed an incremental adjustment of the electronic environment at the copper center that correlated with the extent of ligand fluorination. Furthermore, theoretical calculations (DFT, CASPT2) predicted that an increasing extent of Cu(ii)-superoxo character and end-on coordination of the O(2) moiety in the Cu/O(2) product (L(2) > L(1) > L) are accompanied by increases in the free energy for the oxygenation reaction, with L(2) unable to support a Cu/O(2) intermediate. Calculations also predict the 1 : 1 Cu/O(2) adducts to be unreactive with respect to hydrogen atom abstraction from hydrocarbon substrates on the basis of their stability towards both reduction and protonation.

Reactions between a sodium amide Na[N(SiMe3)R1] (R1= SiMe3, SiMe2Ph or But) and a cyanoalkane RCN (R = Ad or But)

Reactions between sodium amides Na[N(SiMe3)R1] [R1 = SiMe3 (1), SiMe2Ph (2) or But (3)] and cyanoalkanes RCN (R = Ad or But) were investigated. In each case the nitrile adduct [Na{mu-N(SiMe3)2}(NCR)]2 [R = Ad (1a) or But (1b)], trans-[Na{mu-N(SiMe3)(SiMe2Ph)}(NCR)]2 [R = Ad (2a) or But (2b)], [(Na{mu-N(SiMe3)But})3(NCAd)3] (3a) or [(Na{mu-N(SiMe3)But})3(NCBut)n] [n = 3 (3b) or 2 (3c)] was isolated. The reaction of complexes 3a or 3b with benzene afforded the ketimido complex [Na{mu-N=C(Ad)(Ph)}]6.2C6H6 (4a) or [Na{mu-N=C(But)(Ph)}]6 (4b); the former was also prepared in more conventional fashion from NaPh and AdCN. The synthesis and structure of an analogue of complex 1a, [Li{mu-N(SiMe3)2}(NCAd)]2 (5a), is also presented. The compounds 1a, 1b, 2a, 2b, 3, 3b, 4a, 4b and 5a were characterised by X-ray diffraction.

Uranium(III)/(IV) Nitrile Adducts Including UI4(N⋮CPh)4, a Synthetically Useful Uranium(IV) Complex

The synthesis of complexes used to elucidate an understanding of fundamental An(III) and An(IV) coordination chemistry requires the development of suitable organic-soluble precursors. The reaction of oxide-free uranium metal turnings with 1.3 equivalents of elemental iodine in acetonitrile provided the U(III)/U(IV) complex salt, [U(N[triple bond]CMe)9][UI6][I] (1), in which the U(III) cation is surrounded by nine acetonitrile molecules in a tricapped trigonal prismatic arrangement, a [UI6]2- counterion, and a noncoordinating iodide. The U-N distances for the prismatic and capping nitrogens are 2.55(3) and 2.71(5) A, respectively. The same reaction performed in benzonitrile afforded crystalline UI4(N[triple bond]CPh)4 (3) in 78% isolated yield. In the solid state, 3 shows an eight-coordinate U(IV) atom in a "puckered" square antiprismatic geometry with U-N and U-I distances of 2.56(1) and 3.027(1) A, respectively. This benzonitrile UI4 adduct is a versatile U(IV) synthon that is soluble in methylene chloride, benzonitrile, and tetrahydrofuran, and moderately soluble in toluene and benzene, but decomposes in benzonitrile at 198 degrees C to [UI(N[triple bond]CPh)8][UI]6 (4), a U(III)/U(IV) salt analogous to 1. A toluene slurry of 3 treated with 2.2 equiv of Cp*MgCl.THF (Cp* = pentamethylcyclopentadienide) provided Cp*2UI2(N[triple bond]CPh) (5) in low yields. Single-crystal X-ray structure determination shows that the iodide ligands in 5 are in a rare cis configuration with an acute I-U-I angle of 83.16(7) degrees . Treatment of a methylene chloride solution of 3 with KTp* (Tp* = hydridotris(3,5-dimethylpyrazolylborate)) formed green TpUI3 (6) which was converted to yellow Tp*UI3(N[triple bond]CMe) (7) by rinsing with acetonitrile. Addition of 2.2 equiv of KTp* to a toluene solution of 3 followed by heating at 95 degrees C, filtration, and crystallization led to the isolation of the dinuclear species [Tp*UI(dmpz)]2[mu-O] (9) (dmpz = 3,5-dimethylpyrazolide), presumably formed by hydrolytic cleavage of excess KTp* by adventitious water. The Tp* complexes 6, 7, and 9 were characterized by single-crystal X-ray diffraction, NMR, FT-IR, and optical absorbance spectroscopies.

Syntheses, Structures and Vibrational Spectroscopy of Some Adducts of Copper(I) Cyanide with Unidentate Organic Nitriles

Abstract A number of adducts of copper(I) cyanide, CuCN, have been synthesized by crystallization from its solutions in various unidentate organic nitriles, RCN. Low temperature single crystal X-ray structure determinations are recorded for a number of these, of the form CuCN : RCN (m : n) for R = Me, Et (m : n = 1 : 1), and Ph, o-tolyl (3:2). The 1 : 1 adduct with acetonitrile is a two-dimensional polymeric web, (CN)Cu(μ-CN)2Cu(NC) units being linked by the peripheral nitrogen and carbon atoms, with a fourth coordination site about each copper having MeCN pendant. The other three adducts are onedimensional polymers, the propionitrile adduct being of the form . . .Cu(NCEt)CNCu(NCEt)CN. . . with trigonal planar copper, the bridging cyanide groups being replaced in the benzo- and o-toluo nitrile adducts by linear Cu(CN)−2 moieties. The vibrational spectra of bulk samples are largely consistent with the single crystal structural results, but reveal the possible existence of adducts of higher CuCN content in the case of the CuCN/benzonitrile system.

Probing Dynamic Equilibria between Platinum(II)−η2-Benzene Adducts and Unobserved Five-Coordinate Platinum(IV) C−H Oxidative Addition Intermediates

Low-temperature addition of nitrile ligands to platinum(II) η2-benzene reagents, [(κ2-HTp‘)Pt(η2-C6H6)(R)][BAr‘4] (R = H, Ph), results in reversible trapping of the postulated five-coordinate C−H oxidative addition product to give cationic platinum(IV) nitrile adducts, [(κ2-HTp‘)Pt(C6H5)(H)(R)(NCR‘)][BAr‘4] (R = Ph, H, R‘ = Me, CMe3, p-XC6H4). At higher temperatures, irreversible loss of benzene from the Pt(II) η2-benzene reagents occurs to form cationic Pt(II) nitrile products.

Heteroatom-Substituted Carbene Complexes of High-Valent Tungsten: Tp‘W(O)X(C(R)OSiR3) Derivatives

Reaction of Tp‘W(O)(I)(CO) (1; Tp‘ = hydridotris(3,5-dimethylpyrazolyl)borate) with MeLi followed by trapping of the resultant anion by ClSiPh2Me leads to the formation of a single isomer of the tungsten(VI) heteroatom-substituted carbene complex Tp‘W(O)(I)(C(Me)OSiPh2Me) (5a). The connectivity of complex 5a was confirmed by X-ray crystallography and spectral data. The acyl intermediate in the reaction, [Tp‘W(O)(I)(C(O)Me)][Li] (6), was observed by spectroscopic techniques. Trapping of the acyl intermediate 6 with H+ yields the neutral hydroxy carbene complex Tp‘W(O)(I)(C(Me)OH) (5c). Reaction of complex 1 with PhLi generates the anionic phenyl−acyl complex [Tp‘W(O)(I)(C(O)Ph)][Li] (8), which may be trapped with ClSiPh2Me, yielding the phenyl carbene complex Tp‘W(O)(I)(C(Ph)OSiPh2Me) (7). Carbene complex 5a reacts with AgSO3CF3 to form silver iodide and a coordinated triflate complex, Tp‘W(O)(OSO2CF3)(C(Me)OSiPh2Me) (9). In contrast to the acyl product formed with MeLi and 1, combining LiCuMe2 with 1 leads to the replacement of iodide by a methyl group to form Tp‘W(O)(Me)(CO) (2). Protonation of this methyl tungsten complex (2) in CH2Cl2 in the presence of acetonitrile yields methane and the cationic nitrile adduct [Tp‘W(O)(CO)(NCMe)]+ (3), while protonation of 2 in neat acetonitrile produces a cationic hydroxy carbene complex, [Tp‘W(O)(NCMe)(C(Me)OH)]+ (4).

Synthesis, characterization and reactivity of ReOMe 2(bipy)X complexes

The complexes cis- and trans-ReOMe 2(bipy)Cl, where cis or trans refers to the Me–Re–Me regiochemistry, were observed to react as follows: (1) with the alkylating agents RMgCl (R=CH 2SiMe 3 and CH 2Ph) and RLi (R=Me) to give ReOMe 2(bipy)R, and (2) with the alkoxides NaOR′ (R′=Me and Et) to give trans-ReOMe 2(bipy)(OR′). The complex ReOMe 2(bipy)CH 2SiMe 3 was observed by 1H NMR spectroscopy to undergo trans to cis isomerization, which proceeded via reversible first-order kinetics, with Δ H°=1.60(4) kcal mol −1 and Δ S°=3.7(1) eu. At room temperature, Δ G°=0.5(1) kcal mol −1 and K eq=0.42(2), indicating a weak thermodynamic preference for the trans isomer. The activation parameters for the trans to cis isomerization were Δ H ‡ 1=26(2) kcal mol− 1 and Δ S ‡ 1=10(7) eu, and those for the reverse cis to trans isomerization were Δ H ‡ −1=27(2) kcal mol −1 and Δ S ‡ −1=14(7) eu. Treatment of a mixture of cis- and trans-ReOMe 2(bipy)CH 2SiMe 3 with anhydrous HCl gave ReOMe(bipy)(CH 2SiMe 3)Cl; similar treatment of ReOMe 3(bipy) and ReOMe 2(bipy)CH 2Ph gave cis-ReOMe 2(bipy)Cl. Exposure of ReOMe(bipy)(CH 2SiMe 3)Cl to AgPF 6 in acetonitrile-d 3 gave the cationic nitrile adduct [ReOMe(bipy)(CH 2SiMe 3)(CD 3CN)][PF 6].

Syntheses and structures of methyltris(pyrazolyl)silane complexes of the group 6 metals.

The methyltris(3,5-dimethylpyrazolyl)silane ligand, TpsMe2, was readily prepared by the metathesis reaction of methyltrichlorosilane with 3 equiv of lithium 3,5-dimethylpyrazolate. The octahedral tricarbonyl complexes (TpsMe2)M(CO)3 were synthesized either by ligand exchange with the labile nitrile adducts M(CO)3(NCR)3 (M = Cr, Mo, R = Me; M = W, R = Et) or thermally by direct substitution on the hexacarbonyls M(CO)6 (M = Cr, Mo). The three new complexes were characterized by a combination of analytical and spectroscopic techniques, including electrospray ionization mass spectrometry and single-crystal X-ray diffraction. They are all isostructural and display in the solid state the expected distorted octahedral geometries with facially coordinated tris(pyrazolyl)silane ligands. Crystallographic data were used to calculate the ligand cone angles (251-264 degrees) in (TpsMe2)M(CO)3 and also to estimate a value of 1.59 A for the covalent radius of octahedral W(0).

Radical-capturing reaction of 5,7,3',4'-tetramethylquercetin with the AIBN radical initiator.

In order to clarify the mechanism for the radical-capturing reaction which is initiated at the C3-hydroxyl group of flavonols, 5,7,3',4'-tetramethylquercetin (TMQ) was reacted with the 2,2'-azobis-isobutyronitrile (AIBN) radical initiator in benzene. Six products, one depside and its two hydrolytic products, one nitrile adduct, and two others, were isolated from the reaction mixture, and their structures were determined by instrumental analyses. The quantitative change to the four main products against the reaction time was measured by an HPLC method. The radical-capturing reaction pathway for TMQ with AIBN is proposed from these products and their quantitative changes. The pathway dividing into two clearly reveals that one subpath formed the depside and its hydrolytic products, while the other formed the nitrile adduct. The reactivity of each two sub-path was nearly the same, different from the case of TMQ and the 2,2'-azobis-2,4-dimethylvaleronitrile (AMVN) radical initiator.

Structure and Reactivity of η2(3e)-Nitrile and η2(3e)-Alkyne Complexes of Niobium

Nitrile adducts of the type Tp*Nb(CO)(PhC⋮CMe)(RC⋮Ν) (Tp* = hydridotris(3,5-dimethylpyrazolyl)borate; R = Me (2a), Et (2b), PhCH2 (2c), 4-MeOC6H5 (2d), Ph (2e), 4-CF3C6H5 (2f)) have been prepared in fair yields by CO displacement from Tp*Nb(CO)2(PhC⋮CMe) (1) and fully characterized. 13C NMR spectroscopy (δ 180−190 for the nitrile and alkyne contact carbons) and X-ray crystallography (for 2b) indicate an η2-coordination and an unprecedented formally three-electron-donor (3e) behavior for both the alkyne and the nitrile. Electrochemical studies suggest that an equilibrium between this η2(3e)-nitrile/η2(3e)-alkyne form and an otherwise undetected η1(2e)-nitrile/η2(4e)-alkyne form exists in solution. PhC⋮N is thermally displaced from 2e by PMe2Ph or PhC⋮CMe to give Tp*Nb(CO)(PhC⋮CMe)(PMe2Ph) or Tp*Nb(CO)(PhC⋮CMe)2 (3a), respectively. 3a does not react with PMe2Ph. Protonation of 2b with HBF4 induces nitrile/alkyne coupling to give the niobacycle Tp*NbF(CPhCMeCPhNH), via the isolated η2-iminoacyl alkyne cation [Tp*Nb(CO)(η2-CPhNH)(PhC⋮CMe)][BF4], characterized by NMR spectroscopy at 243 K. Protonation of 3a with HBF4 leads to the niobacycle Tp*NbF[C(Ph)C(Me)C(CMeCPhH)O] (X-ray structure), in which CO is included in the alkyne coupling reaction. The intermediate [Tp*Nb(CO)(CMeCPhH)(PhC⋮CMe)][BF4] has been characterized by NMR at 193 K. A deshielded Cα (δ 205), a shielded Cβ (δ 97), and a reduced 1JCH(114 Hz) suggest that a β-CH agostic interaction stabilizes this vinyl alkyne cation. Protonation of the new phosphinoalkyne derivative Tp*Nb(CO)(PhC⋮CMe)(PPh2C⋮CPh) affords the stable phosphonium complex {Tp*Nb(CO)[Ph2P(H)C⋮CPh](PhC⋮CMe)}[BF4], in which the two alkyne ligands act as 3e donors.

Synthesis of Aromatic Nitriles via the Temporary Complexation of Nitroarenes to the Cationic Cyclopentadienyliron Moiety

Cyanide addition to cyclopentadienyliron complexes of substituted nitroarenes produced nitrile adducts where the cyano group added in the ortho position with respect to the nitro group. Cleavage of the cyclopentadienyliron moiety via oxidative demetalation with DDQ led to the isolation of functionalized aromatic nitriles in good yields.