Formation of Osmium-Allylphosphinomethanide Complexes by

Dec 19, 2011 - Ruth Castro-Rodrigo , Miguel A. Esteruelas , Ana M. López , and Enrique Oñate. Organometallics 2012 31 (5), 1991-2000. Abstract | Full ...
3 downloads 0 Views 409KB Size
Download PDF
Article pubs.acs.org/Organometallics

Formation of Osmium-Allylphosphinomethanide Complexes by Coupling of an Isopropenyldiisopropylphosphine and Monosubstituted Allenes Miguel A. Esteruelas,* Ana M. López,* Silvia Mozo, and Enrique Oñate Departamento de Química Inorgánica−Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza−CSIC, 50009 Zaragoza, Spain S Supporting Information *

ABSTRACT: Complex [Os(η5-C5H5){κ3-P,C,C-PiPr2[C(Me) CH2]}(MeCN)]PF6 (1) reacts with cyclohexylallene and ethyl carboxylate allene to give the allylphosphinomethanide derivatives [Os(η 5 -C 5 H 5 ){κ 5 -P,C a ,C b ,C c ,C d -P i Pr 2 [C a (Me)CH 2 C b (C c H 2 )CdHR]}]PF6 (R = Cy (2), CO2Et (3)). In fluorobenzene at 95 °C, complexes 2 and 3 evolve into the corresponding γ-allyl-α-alkenyldiisopropylphosphine compounds [OsH(η5-C5H5){κ4-P,Ca,Cb,CcPiPr2[C(CH2)CH2Ca(CbH2)CcHR]}]PF6 (R = Cy (4), CO2Et (5)). Complexes 2 and 4 have been characterized by X-ray diffraction analysis.

■

INTRODUCTION Functionalization of the C−H bond is one of the most powerful, valuable, straightforward methods for producing complex molecules and for the construction of C−C bond frameworks.1 A long-standing challenge in synthetic chemistry is the direct selective functionalization of C(sp3)−H bonds.2 In contrast to alkyls, the reactions involving alkenyls are usual processes regarding synthetic applications.3 Thus, alkyl dehydrogenation seems to be a reasonable first step in order to perform C(sp3)−H functionalization.4 Although the process is thermodynamically unfavorable, the equilibrium is shifted to the right by adding a hydrogen acceptor.5 In agreement with this, we have converted one of the triisopropylphosphine ligands of Os(η5-C5H5)Cl(PiPr3)26 into γ-allyl-α-alkenyl-, αallyl-, γ-benzoallyl-α-alkenyl-, azabutadienyl-, dihydronaphthyl-, and dienyldiisopropylphosphines via an isopropenyldiisopropylphosphine intermediate (Scheme 1), which was generated by hydrogen transfer from one of the isopropyl substituents of one of the phosphine ligands of the starting compound to diphenylacetylene.7 The functionalization processes involve the coupling of the isopropenyl group with internal alkynes,8 diazoalkanes,9 benzonitriles,10 phenylacetylene,11 and terminal alkynes and alkynols,12 respectively. Allenes are 1,2-dienes with two π-orbitals perpendicular to each other, which exhibit reactivities very different from those of alkenes and alkynes. Today, they are established members of the tools utilized in modern organic synthetic chemistry, in particular for reactions promoted by transition metals.13 The coordination of one of the carbon−carbon double bonds to the metal center produces the activation of the allene, which can then undergo several reactions including C−C and C− heteroatom couplings.14 In this context, we have shown that gem-disubstitued allenes can act as the hydrocarbon component to the formation of allyl © 2011 American Chemical Society

Scheme 1

ligands with a pendant diamine group, by assembly with two allylamines15 and undergo metal-promoted activation of both C−H bonds of the terminal CH2 group to afford hydride− alkenylcarbyne compounds.16 Recently we have also observed that they are efficient hydrogen acceptors for the dehydrogenation of triisopropylphosphine to give isopropenyldiisopropylphosphine derivatives17 (Scheme 2). The ability of the allenes to promote C−C couplings prompted us to investigate the reactions of the isopropenyldiisopropylphosphine complex [Os(η5-C5H5){κ3-P,C,C-PiPr2[C(Me)CH2]}(MeCN)]PF6 (1) with cyclohexylallene and ethyl carboxylate allene, as a part of our work on the Received: November 3, 2011 Published: December 19, 2011 440

dx.doi.org/10.1021/om201077b | Organometallics 2012, 31, 440−444

Organometallics

Article

novel allylphosphinomethanide ligand. As expected the C(10)− Os−P(1) angle of 45.37(15)° is small and similar to those found in various M(κ2-P,C-R2PCHR’) derivatives.18 The bond lengths within the three-membered ring compare well with those found in complex Os(η 6 -1,3,5-C 6 H 3 Me 3 )Cl(κ 2 P,C-iPr2CHCO2Me).18a The Os−P(1) distance is 2.3021(14) Å, whereas the P(1)−C(10) bond length of 1.759(6) Å is about 0.08 Å shorter than the distances P(1)−C(16) and P(1)− C(13). Although this appears to suggest some double-bond character for P(1)−C(10), it should be noted that the Os− C(10) distance of 2.258(5) Å is about 0.1 Å longer than the usual Os−C(sp2) distances in Os-ethylene compounds.20 The allyl group coordinates to the metal center with a C(1)− Os−C(3) angle of 65.8(2)° in the endo form,21 with the substituted C(3) atom cisoid disposed to P(1) and the cyclohexyl group in anti position with regard to the meso carbon atom C(2). In agreement with other Os-allyl complexes,22 the coordination of the C3 skeleton is asymmetric. The separation between the central carbon atom, C(2), and the metal (2.186(5) Å) is shorter than the separations between the metal and the terminal carbon atoms C(1) (2.189(6) Å) and C(3) (2.277(6) Å). The carbon−carbon distances within the allylic skeleton are 1.422(8) Å for C(1)−C(2) and 1.423(8) Å for C(2)−C(3). The 1H, 13C{1H}, and 31P{1H} NMR spectra of 2 in dichloromethane-d2 at room temperature are consistent with the structure shown in Figure 1. In agreement with the presence of three inequivalent allylic protons, the 1H NMR spectrum shows three allylic resonances at 4.58, 3.41, and 3.34 ppm. The CH2 bridge signals are observed at 3.53 and 2.53 ppm. In the 13C{ 1 H} NMR spectrum, the resonance corresponding to C(10) appears at −14.3 ppm as a doublet (JC−P = 11 Hz), whereas the signal due to the bridge C(11) carbon atom is observed at 35.5 ppm also as a doublet (JC−P = 6 Hz). The allylic resonances appear at 70.8 (C(2)), 67.0 (C(3)), and 39.0 (C(1)) ppm. The 31P{1H} NMR spectrum contains a singlet at −30.8 ppm. The 1H, 13C{1H}, and 31P{1H} NMR spectra of 3 agree well with those of 2. In the 1H NMR spectrum, the allylic resonances are observed at 4.75, 4.48, and 3.79 ppm, whereas the bridge CH2 signals appear at 3.67 and 2.68 ppm. The 13C{1H} NMR spectrum shows the CP and bridge CH2 resonances at −11.9 and 35.5 ppm as doublets with C−P coupling constants of 13 and 6 Hz, respectively, whereas the allylic signals are observed at 70.5, 43.2, and 42.1 ppm. The 31 1 P{ H} NMR spectrum contains a singlet at −25.5 ppm. Complexes 2 and 3 are thermally unstable. Heating of their fluorobenzene solutions at 95 °C gives rise to the corresponding γ-allyl-α-alkenyldiisopropylphosphine derivatives [OsH(η5-C5H5){κ4-P,Ca,Cb,Cc-PiPr2[C(CH2)CH2Ca(CbH2)CcHR]}]PF6 (R = Cy (4), CO2Et (5)), as a result of a βelimination reaction on the methyl substituent at the methanidic carbon atom. After 48 h, complexes 4 and 5 were isolated as yellow and brown solids in 71% and 63% yield, respectively (eq 2).

Scheme 2

functionalization of triisopropylphosphine via isopropenyldiisopropylphosphine intermediates.

■

RESULTS AND DISCUSSION

Treatment of acetone solutions of 1 with 1.2 equiv of the allenes under reflux for 5−7 days leads to the allylphosphinomethanide derivatives [Os(η 5 -C 5 H 5 ){κ 5 -P,C a ,C b ,C c ,C d PiPr2[Ca(CH3)CH2Cb(CcH2)CdHR]}]PF6 (R = Cy (2), CO2Et (3)), as a result of the displacement of the acetonitrile molecule from 1 by the allenes and the subsequent oxidative coupling between the terminal CH2 group of the isopropenyl substituent of the phosphine and the central carbon atom of the allenes. Complexes 2 and 3 were isolated as brown and orange solids in 83% and 58% yield, respectively, according to eq 1.

Phosphinomethanide ligands are known in transition metal chemistry.18 However, as far as we know, allylphosphinomethanide ligands have no precedent. We note that, in contrast to 1, the ruthenium−allyldiphenylphosphine complex [Ru(η5-C5Me5){κ3P,C,C-PPh2(CH2CHCH2)}(MeCN)]PF6 reacts with monosubstituted and gem-disubstituted allenes to give dienylphosphine derivatives, as a consequence of the Markovnikov C−H addition of one of the C(sp2)−H bonds of the allyl substituent of the phosphine to the substituted double bond of the allenes.19 Complex 2 has been characterized by X-ray diffraction analysis. The structure (Figure 1) proves the formation of the

Figure 1. Molecular diagram of the cation of 2. Selected bond lengths (Å) and angles (deg): Os−P(1) 2.3021(14), Os−C(1) 2.189(6), Os− C(2) 2.186(5), Os−C(3) 2.277(6), Os−C(10) 2.258(5), C(1)−C(2) 1.422(8), C(2)−C(3) 1.423(8), P(1)−C(10) 1.759(6), P(1)−C(13) 1.839(5), P(1)−C(16) 1.835(6), C(10)−Os−P(1) 45.37(15), C(1)− Os−C(3) 65.8(2), C(1)−C(2)−C(3) 117.1(5). 441

dx.doi.org/10.1021/om201077b | Organometallics 2012, 31, 440−444

Organometallics

Article

resonances at 98.8, 39.1, and 27.1 ppm. The 31P{1H} NMR spectrum contains a singlet at 43.7 ppm, shifted by 74.5 ppm toward lower field with regard to that of 5. Scheme 3 rationalizes the transformation summarized in eq 2. The π−σ equilibrium of the allyl moiety of 2 and 3 should Scheme 3

Figure 2. Molecular diagram of the cation of 4. Selected bond lengths (Å) and angles (deg): Os−P 2.3157(10), Os−C(1) 2.178(5), Os− C(2) 2.167(4), Os−C(3) 2.237(4), C(1)−C(2) 1.428(6), C(2)− C(3) 1.405(6), C(1)−Os−C(3) 64.88(17), C(1)−C(2)−C(3) 113.5(4).

Complex 4 has been characterized by X-ray diffraction analysis. The structure (Figure 2) proves the formation of the η3-allyl-(C(1)-C(2)-C(3))-alkenyl-(C(5)-C(6))-phosphine ligands. The β-elimination is accompanied by an isomerization of the allyl moiety and a change in the disposition of the C3 skeleton with regard to the phosphorus atom. The allyl moiety coordinates to the metal center with a C(1)−Os−C(3) angle of 64.88(17)° in the endo form. In contrast to 2, the substituted C(3) atom is transoid disposed to P and the cyclohexyl substituent now lies in syn position with regard to the meso carbon atom C(2). The separation between the central carbon atom, C(2), and the metal (2.167(4) Å) is shorter than the separation between the metal and the terminal carbon atoms C(1) (2.178(5) Å) and C(3) (2.237(4) Å). The carbon− carbon distances within the allylic skeleton are 1.428(6) Å for C(1)−C(2) and 1.405(6) Å for C(2)−C(3). The Os−P bond length of 2.3157(10) Å is only about 0.01 Å longer than that of 2. The 1H, 13C{1H}, and 31P{1H} NMR spectra of 4 in dichloromethane-d2 at room temperature are consistent with the structure shown in Figure 2. The 1H NMR spectrum shows the alkenyl−C(6)H2 resonances at 6.09 and 5.54 ppm, whereas the C(4)H2 signals appear at 4.11 and 2.62 ppm. The allylic resonances are observed at 3.83, 2.64, and 2.60 ppm. In the high-field region, the hydride ligand displays a doublet at − 15.99 ppm (JH−P = 34.3 Hz). In the 13C{1H} NMR spectrum, the resonances corresponding to C(6), C(5), and C(4) appear at 127.4, 146.7 (JC−P = 41 Hz), and 36.3 (JC−P = 18 Hz) ppm, respectively, whereas the allylic signals are observed at 94.8 (C(2), JC−P = 4 Hz), 65.9 (C(3), JC−P = 7 Hz), and 25.4 (C(1), JC−P = 3 Hz) ppm. The 31P{1H} NMR spectrum contains a singlet at 42.6 ppm, shifted by 73.4 ppm toward lower field with regard to that of 2. The 1H, 13C{1H}, and 31P{1H} NMR spectra of 5 agree well with those of 4. In the 1H NMR spectrum, the alkenyl CH2 resonances appear at 6.11 and 5.58 ppm, whereas the bridge CH2 signals are observed at 4.26 and 3.84 ppm. The inequivalent allylic protons display resonances at 4.17, 2.96, and 2.80 ppm. The hydride gives rise to a doublet at −15.38 ppm (JH−P = 34.3 Hz). In the 13C{1H} NMR spectrum, the alkenyl resonances appear at 146.9 and 127.2 ppm, whereas that corresponding to the bridge CH2 group is observed at 35.6 ppm. The allylic carbon atoms display

afford the unsaturated intermediate A, which could evolve by βhydrogen elimination on the methyl substituent at the methanidic carbon atom into B. The reductive elimination of the σ-allyl and the subsequent coordination of the C1−C2 double bond should generate C. Thus, the rotation of the CH2R group around the C2−C3 single bond would give D, which could change the anti disposition of R with regard to the meso C2 carbon atom to syn. Finally, a C3−H bond activation behind the coordinated double bond of D should lead to 4 and 5.

■

CONCLUDING REMARKS In conclusion, allenes dehydrogenate triisopropylphosphine coordinated to the Os(η5-C5H5) metal fragment,17 and those that are monosubstituted couple with the isopropenyl substituent of the generated isopropenyldiisopropylphosphine to afford novel allylphosphinomethanide ligands, which slowly evolve into γ-allyl-α-alkenyldiisopropylphosphines in fluorobenzene at 95 °C.

■

EXPERIMENTAL SECTION

General Procedures. All reactions were carried out under argon with rigorous exclusion of air using Schlenk-tube techniques. Solvents were dried by the usual procedures and distilled under argon prior to use. The starting material [Os(η5-C5H5){κ3-P,C,C-PiPr2[C(Me) CH2]}(MeCN)]PF6 (1) was prepared according to the published method.17 Chemical shifts (expressed in parts per million) are referenced to residual solvent peaks (1H, 13C{1H}) or external H3PO4 (31P{1H}). Coupling constants, J, are given in hertz. Preparation of [Os(η5-C5H5){κ5-P,Ca,Cb,Cc,Cd-PiPr2[Ca(CH3)CH2Cb(CcH2)CdHCy]}]PF6 (2). A solution of 1 (140 mg, 0.23 mmol) in 9 mL of acetone was treated with cyclohexylallene (37 μL, 0.25 mmol) under reflux for 5 d. The resulting solution was filtered through Celite and concentrated to ca. 1 mL. The addition of pentane caused the formation of a light brown solid, which was separated by decantation, washed with pentane, and dried in vacuo. Yield: 130 mg (83%). Anal. Calcd for C23H38F6OsP2: C, 40.58; H, 5.63. Found: C, 40.08; H, 6.08. HRMS (electrospray, m/z): calcd for C23H38OsP [M]+ 537.2321, found 537.2344. IR (ATR, cm−1): ν(PF6) 833 (s). 1H NMR (300 MHz, CD2Cl2, 298 K): δ 5.38 (s, 5H, C5H5), 4.58 (dd, JHH = JHH = 1.9, 1H, OsCH2), 3.53 (dd, JHP = 18.5, JHH = 14.3, 1H, −CH2−), 3.41 (dddd, JHH = 9.8, JHP = 5.6, JHH = JHH = 1.9, 1H, CHCy), 3.34 (dd, JHH = JHH = 1.9, 1H, OsCH2), 2.53 (ddd, JHH = 14.3, JHP = 9.8, JHH = 1.9, 1H, −CH2−), 2.30 (m, 1H, PCH), 1.80 (m, 1H, PCH), 1.71 − 1.05 (m, 10H, Cy), 1.58 (dd, JHP = 19.0, JHH = 7.3, 442

dx.doi.org/10.1021/om201077b | Organometallics 2012, 31, 440−444

Organometallics

Article

JHP = 12.3, JHH = 2.7, 1H, PCCHcis to P), 4.26 (dd, JHP = 31.3, JHH = 16.4, 1H, −CH2−), 4.17 (dd, JHH = 7.2, JHH = 7.1, 1H, CHCO2Et), 4.12 (partially overlapped, 2H, OCH2CH3), 3.84 (dd, JHH = 16.4, JHP = 1.0, 1H, −CH2−), 2.96 (d, JHH = 1.0, 1H, OsCH2), 2.80 (dd, JHP = 5.3, JHH = 1.0, 1H, OsCH2), 2.38 (m, 1H, PCH), 1.94 (m, 1H, PCH), 1.25 (partially overlapped, 3H, OCH2CH3), 1.17 (dd, JHP = 15.7, JHH = 7.0, 3H, PCHCH3), 1.16 (dd, JHP = 16.9, JHH = 7.3, 3H, PCHCH3), 1.06 (dd, JHP = 16.7, JHH = 6.9, 3H, PCHCH3), 1.04 (dd, JHP = 17.9, JHH = 6.9, 3H, PCHCH3), −15.38 (d, JHP = 34.3, 1H, OsH). 31P{1H} NMR (162 MHz, CD2Cl2, 298 K): δ 43.7 (s), −144.3 (sept, JPF = 711, PF6). 13 C{1H} NMR (126 MHz, CD2Cl2, 298 K): δ 172.7 (s, CO), 146.9 (d, JCP = 41, P−C), 127.2 (s, PCCH2), 98.8 (d, JCP = 4, Os− Cmeso), 85.5 (s, C5H5), 61.5 (s, OCH2CH3), 39.1 (br, CHCO2Et), 35.6 (d, JCP = 17, −CH2−), 31.5 (d, JCP = 40, PCH), 27.6 (d, JCP = 29, PCH), 27.1 (d, JCP = 3, OsCH2), 18.7 (s, PCHCH3), 18.4 (s, PCHCH3), 17.7 (s, PCHCH3), 17.4 (d, JCP = 2, PCHCH3), 14.2 (s, OCH2CH3).

3H, PCHCH3), 1.53 (dd, JHP = 16.4, JHH = 7.3, 3H, PCHCH3), 1.51 (dd, JHP = 16.1, JHH = 7.1, 3H, PCHCH3), 1.34 (d, JHP = 9.3, 3H, PC(CH3)), 1.24 (dd, JHP = 14.8, JHH = 7.3, 3H, PCHCH3), 0.37 (br, 1H, Cy). 31P{1H} NMR (121 MHz, CD2Cl2, 298 K): δ −30.8 (s), −144.5 (sept, JPF = 708, PF6). 13C{1H} NMR (75 MHz, CD2Cl2, 298 K): δ 82.8 (s, C5H5), 70.8 (s, Os−Cmeso), 67.0 (d, JC−P = 1.9, CHCy), 43.1 (s, Cy), 40.3 (s, Cy), 39.0 (s, OsCH2), 35.5 (d, JCP = 6, −CH2−), 34.9 (s, Cy), 32.1 (d, JCP = 42, PCH), 26.8 (d, JCP = 2, PC(CH3)), 26.4, 26.3, and 26.2 (all s, Cy), 22.7 (d, JCP = 7, PCHCH3), 20.3 (d, JCP = 4, PCHCH3), 20.0 (d, JCP = 22, PCH), 19.7 (d, JCP = 2, PCHCH3), 19.4 (s, PCHCH3), −14.3 (d, JCP = 11, PC(CH3)). Preparation of [Os(η5-C5H5){κ5-P,Ca,Cb,Cc,Cd-PiPr2[Ca(CH3)CH2Cb(CcH2)CdHCO2Et]}PF6 (3). This complex was prepared as described for 2 starting from 200 mg (0.33 mmol) of 1 and ethyl carboxylate allene (47 μL, 0.40 mmol) under reflux for 7 d. A light orange solid was obtained.23 Yield: 129 mg (58%). HRMS (electrospray, m/z): calcd for C20H32O2OsP [M]+ 527.1750, found 527.1772. IR (ATR, cm−1): ν(CO) 1702 (m), ν(C−O) 1254 (m), ν(PF6) 825 (s). 1H NMR (400 MHz, CD2Cl2, 298 K): δ 5.42 (s, 5H, C5H5), 4.75 (s, 1H, OsCH2), 4.48 (s, 1H, OsCH2), 3.98 (q, JHH = 7.1, 2H, OCH2CH3), 3.79 (d, JHP = 5.4, 1H, CHCO2Et), 3.67 (dd, JHH = 14.4, JHP = 18.2, 1H, −CH2−), 2.68 (dd, JHH = 14.2, JHP = 9.6, 1H, −CH2−), 2.35 (m, 1H, PCH), 1.95 (m, 1H, PCH), 1.61 (dd, JHP = 19.7, JHH = 7.5, 3H, PCHCH3), 1.57 (dd, JHP = 13.8, JHH = 7.3, 3H, PCHCH3), 1.53 (dd, JHP = 13.1, JHH = 7.2, 3H, PCHCH3), 1.36 (d, JHP = 9.4, 3H, PC(CH3)), 1.25 (dd, JHP = 14.9, JHH = 7.5, 3H, PCHCH3), 1.20 (t, JHH = 7.1, 3H, OCH2CH3). 31P{1H} NMR (162 MHz, CD2Cl2, 298 K): δ −25.5 (s), −144.3 (sept, JPF = 711, PF6). 13C{1H} NMR (75 MHz, CD2Cl2, 298 K): δ 171.4 (s, CO), 84.6 (s, C5H5), 70.5 (s, Os−Cmeso), 61.0 (s, OCH2CH3), 43.2 (s, OsCH2), 42.1 (d, JCP = 2.4, CHCO2Et), 35.5 (d, JCP = 6, −CH2−), 31.66 (d, JCP = 41, PCH), 26.7 (d, JCP = 1, PC(CH3)), 22.7 (d, JCP = 7, PCHCH3), 20.9 (d, JCP = 23, PCH), 20.3 (d, JCP = 5, PCHCH3), 19.7 (d, JCP = 2, PCHCH3), 19.4 (s, PCHCH3), 14.6 (s, OCH2CH3), −11.9 (d, JCP = 13, PC(CH3)). Preparation of [OsH(η5-C5H5){κ4-P,Ca,Cb,Cc-PiPr2[C(CH2)CH2Ca(CbH2)]CcHCy]}]PF6 (4). A solution of 2 (105 mg, 0.18 mmol) in 7 mL of fluorobenzene was heated for 2 d at 368 K. The resulting orange solution was filtered through Celite and evaporated to dryness. The addition of dichloromethane and pentane at 195 K afforded a light yellow solid, which was washed with pentane and dried in vacuo. Yield: 85 mg (71%). Anal. Calcd for C23H38F6OsP2: C, 40.58; H, 5.63. Found: C, 40.75; H, 6.07. HRMS (electrospray, m/z): calcd for C23H38OsP [M]+ 537.2321, found 537.2351. IR (ATR, cm−1): ν(OsH) 2112 (w), ν(PF6) 832 (s). 1H NMR (400 MHz, CD2Cl2, 298 K): δ 6.09 (dd, JHP = 29.3, JHH = 2.5, 1H, PCCHtrans to P), 5.62 (s, 5H, C5H5), 5.54 (dd, JHP = 12.5, JHH = 2.5, 1H, PCCHcis to P), 4.11 (dd, JHH = 15.7, JHP = 29.6, 1H, −CH2−), 3.83 (dd, JHH = 9.8, JHP = 2.1, 1H, CHCy), 2.64 (d, JHP = 5.2, 1H, OsCH2), 2.62 (dd, JHH = 15.7, JHP = 1.0, 1H, −CH2−), 2.60 (overlapped by one of the −CH2−, 1H, OsCH2), 2.38 (m, 1H, PCH), 1.94 (m, 1H, PCH), 1.85−1.05 (m, 11H, Cy), 1.15 (dd, JHP = 16.6, JHH = 7.2, 3H, PCHCH3), 1.15 (dd, JHP = 16.0, JHH = 7.0, 3H, PCHCH3), 1.02 (dd, JHP = 17.1, JHH = 6.9, 3H, PCHCH3), 1.02 (dd, JHP = 16.3, JHH = 6.9, 3H, PCHCH3), −15.99 (d, JHP = 34.3, 1H, OsH). 31P{1H} NMR (162 MHz, CD2Cl2, 298 K): δ 42.6 (s), −144.4 (sept, JPF = 711, PF6). 13C{1H} NMR (75 MHz, CD2Cl2, 298 K): δ 146.7 (d, JCP = 41, P−C), 127.4 (s, PCCH2), 94.8 (d, JCP = 4, Os−Cmeso), 84.0 (s, C5H5), 65.9 (d, JCP = 7, CHCy), 42.7 (s, Cy), 36.3 (d, JCP = 18, −CH2−), 35.7 y 35.5 (both s, Cy), 31.8 (d, JCP = 40, PCH), 27.2 (d, JCP = 29, PCH), 26.6, 26.2, and 26.1 (all s, Cy), 25.4 (d, JCP = 3, OsCH2), 18.8 (s, PCHCH3), 18.6 (s, PCHCH3), 17.9 (d, JCP = 1, PCHCH3), 17.7 (d, JCP = 2, PCHCH3). Preparation of [OsH(η5-C5H5){κ4-(P,Ca,Cb,Cc)-PiPr2[C(CH2)CH2Ca(CbH2)CcHCO2Et]}]PF6 (5). This complex was prepared as described for 4 starting from 100 mg (0.17 mmol) of 3. A light brown solid was obtained.23 Yield: 71 mg (63%). HRMS (electrospray, m/z): calcd for C20H32O2OsP [M]+ 527.1750, found 527.1771. IR (ATR, cm−1): ν(OsH) 2291 (w), ν(CO) 1710 (m), ν(C−O) 1260 (m), ν(PF6) 837 (s). 1H NMR (500 MHz, CD2Cl2, 298 K): δ 6.11 (dd, JHP = 30.9, JHH = 2.7, 1H, PCCHtrans to P), 5.75 (s, 5H, C5H5), 5.58 (dd,

■

ASSOCIATED CONTENT * Supporting Information Text and CIF files giving details of the X-ray analysis and crystal structure determination and crystal data for 2 and 4. This material is available free of charge via the Internet at http:// pubs.acs.org. S

■ ■

AUTHOR INFORMATION Corresponding Author *E-mail: [email protected]; [email protected] (A.M.L.). ACKNOWLEDGMENTS Financial support from the Spanish MICINN (Projects CTQ2011-23459 and Consolider Ingenio 2010 (CSD200700006)), the Diputación General de Aragón (E35), and the European Social Fund is acknowledged.

■

REFERENCES

(1) (a) Díaz-Requejo, M. M.; Pérez, P. J. Chem. Rev. 2008, 108, 3379. (b) Webb, J. R.; Bolaño, T.; Gunnoe, T. B. ChemSusChem. 2011, 4, 37. (2) (a) Chen, H.; Schlecht, S.; Semple, T. C.; Hartwig, J. F. Science 2000, 287, 1995. (b) Wan, X.; Wang, X.; Luo, Y.; Takami, S.; Kubo, M.; Miyamoto, A. Organometallics 2002, 21, 3703. (c) Hartwig, J. F.; Cook, K. S.; Hapke, M.; Incarvito, C. D.; Fan, Y.; Webster, C. E.; Hall, M. B. J. Am. Chem. Soc. 2005, 127, 2538. (d) Mkhalid, I. A. I.; Barnard, J. H.; Marder, T. B.; Murphy, J. M.; Hartwig, J. F. Chem. Rev. 2010, 110, 890. (e) Hartwig, J. F. Chem. Soc. Rev. 2011, 40, 1992. (3) (a) Kakiuchi, F.; Murai, S. Acc. Chem. Res. 2002, 35, 826. (b) Kakiuchi, F.; Chatani, N. Adv. Synth. Catal. 2003, 345, 1077. (c) Goj, L. A.; Gunnoe, T. B. Curr. Org. Chem. 2005, 9, 671. (d) Lewis, J. C.; Bergman, R. G.; Ellman, J. A. Acc. Chem. Res. 2008, 41, 1013. (e) Foley, N. A.; Lee, J. P.; Ke, Z.; Gunnoe, T. B.; Cundari, T. R. Acc. Chem. Res. 2009, 42, 585. (f) Colby, D. A.; Bergman, R. G.; Ellman, J. A. Chem. Rev. 2010, 110, 624. (g) Andreatta, J. R.; Mckeown, B. A.; Gunnoe, T. B. J. Organomet. Chem. 2011, 696, 305. (4) (a) Goldman, A. S.; Roy, A. H.; Huang, Z.; Ahuja, R.; Schinski, W.; Brookhart, M. Science 2006, 312, 257. (b) Ahuja, R.; Kundu, S.; Goldman, A. S.; Brookhart, M.; Vicente, B. C.; Scott, S. L. Chem. Commun. 2008, 253. (c) Basset, J.-M.; Copéret, C.; Soulivong, D.; Taoufik, M.; Cazat, J. T. Acc. Chem. Res. 2010, 43, 323. (5) (a) Choi, J.; MacArthur, A. H. R.; Brookhart, M.; Goldman, A. S. Chem. Rev. 2011, 111, 1761. (b) Ahuja, R.; Punji, B.; Findlater, M.; Supplee, C.; Schinski, W.; Brookhart, M.; Goldman, A. S. Nat. Chem. 2011, 3, 167. (6) Esteruelas, M. A.; López, A. M. Organometallics 2005, 24, 3584. (7) Baya, M.; Buil, M. L.; Esteruelas, M. A.; Oñate, E. Organometallics 2004, 23, 1416. (8) Esteruelas, M. A.; Hernández, Y. A.; López, A. M.; Oliván, M.; Oñate, E. Organometallics 2007, 26, 2193. 443

dx.doi.org/10.1021/om201077b | Organometallics 2012, 31, 440−444

Organometallics

Article

(9) Esteruelas, M. A.; González, A. I.; López, A. M.; Oñate, E. Organometallics 2004, 23, 4858. (10) Baya, M.; Esteruelas, M. A.; González, A. I.; López, A. M.; Oñate, E. Organometallics 2005, 24, 1225. (11) Baya, M.; Buil, M. L.; Esteruelas, M. A.; Oñ ate, E. Organometallics 2005, 24, 5180. (12) Baya, M.; Buil, M. L.; Esteruelas, M. A.; Oñ ate, E. Organometallics 2005, 24, 2030. (13) (a) Ma, S. Acc. Chem. Res. 2003, 36, 701. (b) Sydnes, L. K. Chem. Rev. 2003, 103, 1133. (c) Ma, S. Chem. Rev. 2005, 105, 2829. (d) Jeganmohan, M.; Cheng, C.-H. Chem. Commun. 2008, 3101. (e) Ma, S. Acc. Chem. Res. 2009, 42, 1679. (f) Croatt, M. P.; Wender, P. A. Eur. J. Org. Chem. 2010, 19. (g) Alcaide, B.; Almendros, P.; Aragoncillo, C. Chem. Soc. Rev. 2010, 39, 783. (14) (a) Bai, T.; Ma, S.; Jia, G. Coord. Chem. Rev. 2009, 253, 423, and references therein. (b) Gulías, M.; Collado, A.; Trillo, B.; López, F.; Oñate, E.; Esteruelas, M. A.; Mascareñas, J. L. J. Am. Chem. Soc. 2011, 133, 7660. (15) Baya, M.; Esteruelas, M. A.; Oñate, E. Organometallics 2010, 29, 6298. (16) Collado, A.; Esteruelas, M. A.; López, F.; Mascareñas, J. L.; Oñate, E.; Trillo, B. Organometallics 2010, 29, 4966. (17) Castro-Rodrigo, R.; Esteruelas, M. A.; López, A. M.; Mozo, S.; Oñate, E. Organometallics 2010, 29, 4071. (18) See for example: (a) Werner, H.; Henig, G.; Wecker, U.; Mahr, N.; Peters, K.; von Schnering, H. G. Chem. Ber. 1995, 128, 1175. (b) Holland, A. W.; Bergman, R. G. Organometallics 2002, 21, 2149. (c) Henig, G.; Schulz, M.; Windmüller, B.; Werner, H. Dalton Trans. 2003, 441. (d) Cadierno, V.; Díez, J.; García-Á lvarez, J.; Gimeno, J. Organometallics 2004, 23, 3425. (e) Kabir, S. E.; Saha, M. S.; Tocher, D. A.; Hossain, G. M. G.; Rosenberg, E. J. Organomet. Chem. 2006, 691, 97. (f) Rankin, M. A.; Schatte, G.; McDonald, R.; Stradiotto, M. J. Am. Chem. Soc. 2007, 129, 6390. (g) van der Eide, E. F.; Piers, W. E.; Parvez, M.; McDonald, R. Inorg. Chem. 2007, 46, 14. (h) Shiue, T.-W.; Yeh, W.-Y.; Lee, G.-H.; Peng, S.-M. J. Organomet. Chem. 2007, 692, 3619. (19) Villar, A.; Diez, J.; Lastra, E.; Gamasa, M. P. Organometallics 2011, 30, 5803. (20) See for example: Bajo, S.; Esteruelas, M. A.; López, A. M.; Oñate, E. Organometallics 2011, 30, 5710, and references therein. (21) The endo coordination is the preferred structural form in d4M(η5-C5R5)L2(η3-allyl) complexes with L ≠ CO. See for example: (a) Albers, M. O.; Liles, D. C.; Robinson, D. J.; Shaver, A.; Singleton, E. Organometallics 1987, 6, 2347. (b) Itoh, K.; Fukahori, T. J. Organomet. Chem. 1988, 349, 227. (c) Nagashima, H.; Mukai, K.; Shiota, Y.; Yamaguchi, K.; Ara, K.-I.; Fukahori, T.; Suzuki, H.; Akita, M.; Moro-oka, Y.; Itoh, K. Organometallics 1990, 9, 799. (d) Hubbard, J. L.; Zoch, C. R. J. Organomet. Chem. 1995, 487, 65. (e) Mui, H. D.; Brumaghim, J. L.; Gross, C. L.; Girolami, G. S. Organometallics 1999, 18, 3264. (f) Kondo, H.; Yamaguchi, Y.; Nagashima, H. Chem. Commun. 2000, 1075. (g) Bi, S.; Ariafard, A.; Jia, G.; Lin, Z. Organometallics 2005, 24, 680. (22) See for example: (a) Baya, M.; Esteruelas, M. A.; Oñate, E. Organometallics 2001, 20, 4875. (b) Esteruelas, M. A.; González, A. I.; Lóp ez, A. M.; Oñ a te, E. Organonometallics 2003, 22, 414. (c) Esteruelas, M. A.; González, A. I.; López, A. M.; Oliván, M.; Oñate, E. Organometallics 2006, 25, 693. (23) All our attempts to achieve a valid elemental analysis determination for this complex were unsuccessful due to the presence of impurity traces (including solvents) in the sample.

444

dx.doi.org/10.1021/om201077b | Organometallics 2012, 31, 440−444