Cl Phosphinidenoid Complex

Jun 15, 2012 - Reaction of the Li/Cl phosphinidenoid pentacarbonyltungsten complex 2 (R = CH(SiMe3)2) with unsaturated aldehydes 3, 4, 9, 10, and 13 y...
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Probing the Group Tolerance of a Li/Cl Phosphinidenoid Complex Using Alkenyl-Substituted Aldehydes Rainer Streubel,* Melina Klein, and Gregor Schnakenburg Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany S Supporting Information *

ABSTRACT: Reaction of the Li/Cl phosphinidenoid pentacarbonyltungsten complex 2 (R = CH(SiMe3)2) with unsaturated aldehydes 3, 4, 9, 10, and 13 yielded the new oxaphosphirane complexes 5, 7, 11, 12, and 14 and thus revealed a clear preference for CO vs CC bond addition (i) and for 1,2- vs 1,4 addition (ii). Complexes were characterized by NMR, IR spectroscopy, and mass spectrometry and, in the case of 14a, by single-crystal X-ray analysis.

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organic iodides was also observed. Recent results obtained from the reaction of an Li/Cl phosphinidenoid complex with N-Mesubstituted 3-thienyl imine supports the latter reactivity, as a nucleophilic formal [4 + 1] cycloaddition was concluded on the basis of DFT calculations.9 Although these investigations, including a recent study on cyclic ketones,10 provided some insights, the reactivity of M/X phosphinidenoid complexes is still largely unexplored; e.g., the quest for the reaction course of such formal [2 + 1] cycloaddition reactions is far from being solved. Here, we report preliminary results on reactions of the Li/Cl phosphinidenoid complex 2 with aldehydes possessing a remote or conjugated alkenyl moiety: i.e., probing the functional group tolerance of such phosphinidenoid complexes and the course of cycloaddition. First, the reaction of Li/Cl phosphinidenoid complex 2,8 obtained via chlorine/lithium exchange in complex 19 in the presence of 12crown-4, with aldehydes 3 and 4 possessing a pendant alkenyl moiety was investigated. Under these conditions the diastereomeric oxaphosphirane complexes 5a,b and 7a,b (Scheme 2) were obtained. In both cases, it was observed that byproducts in small amounts (6, 10%; 8, 6%) were formed (6, δ(31P) 21.4, 1J(W,P) = 290.9 Hz; 8, δ(31P) 20.2, 1J(W,P) = 290.4 Hz) that exhibited very similar 31P{1H} NMR parameters. Unfortunately, the latter could not be separated using column chromatography or crystallized. Nevertheless, mixtures were

hosphanides I and their complexes II (Scheme 1) are key reagents and ligands in main-group and transition-metal

Scheme 1. Phosphanides I and Phosphinidenoids III and Their Transition-Metal Complexes II and IV

Legend: R, R′ = organic substituents, X = halogen, M = main-group metal, MLn = transition-metal complex.

chemistry alike: e.g., lithium phosphanides1 enable the formation of single and/or multiple bonds between phosphorus and carbon and/or metal atoms. In contrast, phosphinidenoids III possessing a functional group X (Scheme 1) have been neither firmly established nor much used and have been proposed only as intermediates2 and/or precursors for phosphinidenes.3 Interestingly, although they are also highly reactive, transient terminal phosphinidene complexes have become important building blocks during the last few decades.4 Recently, the first protocol to generate Li/X phosphinidenoid transition-metal complexes IV (X = F,5a Cl;5b R = CH(SiMe3)2) was reported, which revealed the particular importance of the presence of 12-crown-4. So far, the nature of the stabilization of this new reactive intermediate is still unclear. Preliminary results on the reactivity of IV (X = Cl) toward nitriles, alkynes, and aldehydes pointed to a phosphinidene complex like behavior,5b but a nucleophilic reactivity5−8 toward © 2012 American Chemical Society

Received: March 2, 2012 Published: June 15, 2012 4711

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Scheme 2. Synthesis of Oxaphosphirane Complexes 5a,b, 7a,b, 11, 12, and 14a,b

and are formed due to this phenomenon. On the other hand, this phenomenon was only observed for C,C′-disubstituted oxaphosphirane derivatives, which are sterically more demanding.

obtained that allowed us to record and unambiguously assign the NMR data of the major isomers 5a and 7a. Then, reactions of complex 2 with the α,β-unsaturated aldehydes 9 and 10 were studied, which selectively furnished oxaphosphirane complexes 11 (δ(31P) 36.0, 1J(W,P) = 301.7 Hz) and 12 (δ(31P) 38.4, 1J(W,P) = 304.9 Hz) (Scheme 2). As these reactions were very selective, no indications of products steming from formal [4 + 1] cycloaddition reactions were obtained, thus showing a clear π-substrate preference for the CO bond. Complexes 11 and 12 could not be purified via column chromatography, as partial decomposition occurred, but filtration and washing at low temperature proved to be successful and yielded 11 as a solid and 12 as an oil; for structurally relevant NMR data see Table 1. In a preliminary investigation the benzyl-substituted aldehyde 13 was used as a case in point for substrates that possess somewhat acidic protons at the α-carbon atom. However, the reaction of complex 2 with 13 proceeded smoothly to the diastereomeric oxaphosphirane complexes 14a,b. Here again, small amounts of a byproduct were observed (9%) (15, δ(31P) 21.7, 1J(W,P) = 300.7 Hz) (Scheme 2) which could not be separated via column chromatography. The molecular structure of complex 14a was confirmed by a single-crystal X-ray diffraction study, but other than a disorder of the phenyl ring (76% vs 24%), it did not reveal any peculiar distances or angles (Figure 1). The s-cis conformation of the CH(SiMe3)2 group (relative orientation of C−H and P−W at the exocyclic P−C bond) is also common for the previously reported oxaphosphirane complex X-ray structures. As it was observed recently7 that this particular arrangement may lead to a P−C atropisomerism in oxaphosphirane complexes, one might be tempted to speculate that the observed byproducts (in the case of 5a,b, 7a,b, and 14a,b) are oxaphosphirane complexes as well

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CONCLUSIONS This first study on reactions of a Li/Cl phosphinidenoid complex with bifunctional π-substrates revealed the following: • an excellent π selectivity toward aldehydes possessing additional CC bonds in the substituent with a clear preference for the CO bond (high group tolerance) • a clear preference for formal 1,2- vs 1,4-addition reactions and, hence, pronounced nucleophilic character • a weak basicity of the phosphorus center When the first and second aspects are combined, it provides good evidence that the formation of the oxaphosphirane ring proceeds via an initial nucleophilic attack of the phosphorus of the phosphinidenoid complex at the aldehyde carbon atom. Nevertheless, further studies will be necessary to achieve a detailed understanding of ring-forming reactions.

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EXPERIMENTAL SECTION

All reactions were carried out under an inert gas atmosphere using purified and dried argon and standard Schlenk techniques. Solvents were dried over sodium wire/benzophenone and distilled under argon. NMR data were recorded on a Bruker DMX 300 spectrometer at 30 °C using C6D6 as solvent and internal standard; chemical shifts are given in ppm relative to tetramethylsilane (1H, 300.13 MHz; 13C, 75.5 MHz; 29Si, 59.6 MHz), and 85% H3PO4 (31P, 121.5 MHz). Mass spectra were recorded on a MAT 95 XL Finnigan (EI, 70 eV, 184W) spectrometer, and IR spectra were recorded on a Thermo Nicolet 380 FTIR spectrometer; selected data are given. Melting points were determined using a Büchi type S apparatus; the values are not corrected. Elemental analyses were performed by using an Elementar VarioEL instrument. 4712

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Table 1. 31P, 1H, and 13C NMR Data (C6D6) of the Major Isomers of Complexes 5, 7, 11, 12, and 14

Complex 5a. “Yield” of the mixture of 5a,b and 6 (69:21:10): 269 mg (0.49 mmol, 58%). Analytical data obtained from this mixture are as follows. 1H NMR: δ 0.12 (s, 18H, Si(CH3)3); 1.09 (s, 1H, CH(Si(CH3)3)2); 1.86−1.54 (m, 2H, CH2); 2.28−2.03 (m, 2H, CH2); 3.03 (t, 1H, 3J(H,H) = 6.1 Hz, CH(P)(O)); 5.10−4.90 (m, 2H, CH2); 5.78−5.57 (m, 1H, CH). 13C{1H} NMR: δ 1.2 (d, 3J(P,C) = 4.8 Hz, Si(CH3)3); 1.4 (s, Si(CH3)3); 30.5 (d, 3J(P,C) = 6.5 Hz, CH2); 30.8 (d, 3.0 Hz, 2J(P,C) = 3.0 Hz, CH2); 29.2 (d, 1J(P,C) = 17.7 Hz, CH(Si(CH3)3)2); 58.9 (d, 1 J(P,C) = 31.1 Hz, CH(P)(O)); 116.2 (s, CH2CH); 136.9 (s, CH2 C(H)); 195.8 (d, 2J(P,C) = 8.4 Hz, cis-CO); 197.7 (d, 2J(P,C) = 33.7 Hz, trans-CO). 29Si{1H} NMR: δ −1.69 (d, 2J(P,Si) = 5.1 Hz); 0.06 (d, 2 J(P,Si) = 8.0 Hz). 31P{1H}NMR: δ 29.6 (1J(W,P) = 299.2 Hz). IR (Nujol, selected data): ν̃ (cm−1) 1255 (s), 1459 (m), 1641 (w), 1953 (s), 1988 (m), 2076 (s), 2854 (s), 2924 (s), 2959 (s). MS (EI, 184W): m/z 598.1 (5) [M]•+, 514.0 (20) [M − 3CO]+, 486.0 (55) [M − 4CO]+, 458.1 (25) [M − 5CO]+, 430.1 (25) [M − 3CO − C5H8O]+, 402.0 (20) [M − 4CO − C5H8O]+, 384.0 (30) [M − 5CO − HSi(CH3)3]+, 374.0 (10) [M − 5CO − C5H8O]+, 358.0 (30) [M − 5CO − Si(CH3)3 − C2H3]+, 341.0 (20) [M − 3CO − CH2 − CH(Si(CH3)3)2]+, 299.0 (10) [M − 5CO − CH(Si(CH3)3)2]+, 129.1 (5) [CH(Si(CH3)3)2]+, 73.1 (100) [Si(CH3)3]+. Anal. Calcd for C17H27O6PSi2W (598.4 g/mol): C, 34.12; H, 4.55. Found: C, 34.57; H, 4.60. Complex 5b. 31P{1H} NMR: δ 34.8 (1J(W,P) = 294.6 Hz). Complex 7a. “Yield” of the mixture of 7a,b and 8 (85:9:6): 325 mg (0.48 mmol, 56%). Analytical data obtained from this mixture are as follows. 1H NMR: δ 0.20 (d, 9H, 4J(P,H) = 1.9 Hz, Si(CH3)3); 0.33 (s, 9H, Si(CH3)3); 1.17 (s, 1H, CH(Si(CH3)3)2); 1.20−1.45 (m, 10H, CH2); 1.49−1.61 (m, 2H, CH2); 1.61−1.90 (m, 2H, CH2); 2.00−2.14 (m, 2H, CH2CHCH2); 3.05−3.15 (m, 1H, CH(P)(O)); 5.02−5.17 (m, 2H, CH2CH); 5.79−5.95 (m, 1H, CH2CH). 13C{1H} NMR: δ 1.2 (d, 3J(P,C) = 3.9 Hz, Si(CH3)3); 1.8 (d, 3J(P,C) = 2.6 Hz, Si(CH3)3); 30.4 (d, 1J(P,C) = 16.2 Hz, CH(Si(CH3)3)2); 29.7 (s, CH2); 29.4 (s, CH2); 29.7 (s, CH2); 29.3 (s, CH2); 26.7 (s, CH2); 26.6 (s, CH2); 31.6 (d, 2J(P,C) = 2.8 Hz, CH2CH(O)P); 34.2 (s, CH2CHCH2); 60.0 (d, 1J(P,C) = 30.7 Hz, CH(P)(O)); 114.5 (s, CH2CH); 139.2 (s, CH2CH); 195.8 (d, 2J(P,C) = 8.4 Hz, cisCO); 197.8 (d, 2J(P,C) = 33.6 Hz, trans-CO). 29Si{1H} NMR: δ −1.9 (d, 2J(P,Si) = 5.1 Hz), −0.1 (d, 2J(P,Si) = 8.0 Hz). 31P{1H} NMR: δ

Figure 1. Molecular structure of 14a. There is 2-fold disorder in the orientation of the phenyl ring (the 76% site is shown); because of the great similarity only one data set is given. Hydrogen atoms are omitted for clarity. Selected bond lengths (Å) and angles (deg): W−P = 2.4635(13), P−O1 = 1.669(4), C1−O1 = 1.491(8), P−C1 = 1.800(7); P−O1−C1 = 69.2(3), C1−P−O1 = 50.8(3), O1−C1−P = 60.1(3). Complexes 5, 7, 11, 12, and 14. To a freshly prepared solution of 2 (0.47 g, 0.85 mmol) in Et2O (15 mL) were added the following aldehydes: 101.2 μL of 3 (86.3 mg, 1.2 equiv), 0.20 mL of 4 (172.5 mg, 1.2 equiv), 84.9 μL of 9 (71.8 mg, 1.2 equiv), 98.9 μL of 10 (86.2 mg, 1.2 equiv), and 99.7 μL of 13 (102.6 mg, 1.0 equiv). The reaction mixture was warmed to room temperature (except for 11 and 12, which were warmed to only −20 °C), and the solvent was removed in vacuo (∼10−2 mbar). From the residues the products 5, 7, 12, and 14 were extracted with n-pentane at ambient temperature and in the case of complex 11 at −20 °C. Complexes 5, 7, and 14 were purified by column chromatography (Al2O3, −20 °C, petroleum ether); products 5, 7 and 14 were all obtained and characterized as mixtures (ratios are given below). 4713

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28.5 (1J(W,P) = 297.3 Hz). IR (Nujol, selected data): ν̃ (cm−1) 1254 (s), 1459 (m), 1641 (w), 1953 (s), 1988 (m), 2076 (s); 2854 (s) 2925 (s), 2958 (s). MS (EI, 184W): m/z 542.1 (5) [M − 5CO]+, 513.9 (15) [M − C11H20O]+, 486.0 (100) [M − CO − C11H20O]+, 458.0 (30) [M − 2CO − C11H20O]+, 432.0 (20) [M − 3CO − C11H20O]+, 402.0 (10) [M − 4CO − C11H20O]+, 358.0 (20) [M − W(CO)5]+, 111.1 (18) [C8H15]+, 97.1 (25) [C7H13]+, 83.1 (30) [C6H11]+, 73.1 (100) [Si(CH3)3]+, 69.1 (35) [C5H9]+, 55.1 (55) [C4H7]+. Anal. Calcd for C23H39O6PSi2W (682.5 g/mol): C, 40.47; H, 5.76. Found: C, 41.66; H, 6.22. Complex 7b. 31P{1H} NMR: δ 33.9 (1J(W,P) = 293.5 Hz). Complex 11. Yield: 259 mg (0.44 mmol, 52%). Mp: 55 °C; 1H NMR: δ 0.10 (s, 9H, Si(CH3)3); 0.12 (s, 9H, Si(CH3)3); 1.13 (s, 1H, CH(Si(CH3)3)2); 1.51 (d, 3J(H,H) = 6.6 Hz, 3H, CHCH(CH3); 3.51 (d, 3J(H,H) = 5.6 Hz, 1H, CH(P)(O)); 5.40−5.53 (m, 1H, CHCH(CH3)); 5.71−5.87 (m, 1H, CHCH(CH3)). 13C{1H} NMR: δ 1.2 (d, 3J(P,C) = 4.2 Hz, Si(CH3)2); 1.7 (d, 3J(P,C) = 2.3 Hz, Si(CH3)2); 17.9 (d, 4J(P,C) = 2.3 Hz, CHCH(CH3)); 31.1 (d, 1 J(P,C) = 19.2 Hz, CH(Si(CH3)3)2); 59.3 (d, 1J(P,C) = 32.4 Hz, CH(P)(O)); 125.5 (s, CH(CH3)CH); 131.4 (d, 2J(P,C) = 9.6 Hz, CHCH(CH3)); 195.8 (d, 2J(P,C) = 8.4 Hz, cis-CO); 197.8 (d, 2 J(P,C) = 34.4 Hz, trans-CO). 29Si{1H} NMR: δ −0.97 (d, 2J(Si,P) = 5.4 Hz); 0.57 (d, 2J(Si,P) = 7.9 Hz). 31P{1H} NMR: δ 36.0 (1J(W,P) = 301.7 Hz). IR (KBr, selected data): ν̃ (cm−1) 967 (m), 1253 (s), 1376 (m), 1449 (m), 1915 (s), 2076 (s), 2901 (m), 2917 (m), 2956 (s). MS (EI, 184W): m/z 583.9 (18) [M]•+, 555.9 (10) [M − CO]+, 527.9 (5) [M − 2CO]+, 513.8 (20) [M − C4H6O]+, 499.9 (8) [M − 3CO]+, 485.9 (80) [M − CO − C4H6O]+, 457.9 (40) [M − 2CO − C4H6O]+, 443.9 (20) [M − 5CO]+, 429.9 (50) [M − 3CO − C4H6O]+, 401.9 (30) [M − 4CO − C4H6O]+, 357.9 (40) [M − 3CO − C4H6O − Si(CH3)3 − H]+, 353.8 (75) [M − 3CO − 2Si(CH3)3]+, 73.0 (60) [Si(CH3)3]+. Anal. Calcd for C16H25O6PSi2W (584.4 g/mol): C, 32.89; H, 4.31. Found: 32.58, 4.75. Complex 12. Yield: 261 mg (0.44 mmol, 51%). 1H NMR: δ 0.15 (s, 9H, Si(CH3)3); 0.16 (s, 9H, Si(CH3)3); 1.16 (s, 1H, CH(Si(CH3)3)2); 1.49−1.56 (m, 3H, C(CH3)CH(CH3)); 1.65 (s, 3H, C(CH3)CH(CH3)); 3.49 (s, br, 1H, CH(P)(O)); 5.64−5.72 (m, 1H, C(CH3)CH(CH3)). 13C{1H} NMR: δ 1.5 (d, 3J(P,C) = 4.1 Hz, Si(CH3)2); 2.0 (d, 3J(P,C) = 2.3 Hz, Si(CH3)2); 12.8 (d, 3J(P,C) = 2.8 Hz, C(CH3)CH(CH3)); 14.2 (s, C(CH3)CH(CH3); 31.9 (d, 1 J(P,C) = 19.9 Hz, CH(Si(CH3)3)2); 61.6 (d, 1J(P,C) = 26.1 Hz, CH(P)(O)); 122.5 (d, 2J(P,C) = 9.0 Hz, CH(CH3)C(CH3)); 129.2 (d, 2J(P,C) = 2.0 Hz, C(CH3)CH(CH3)); 195.8 (d, 2J(P,C) = 8.3 Hz, cis-CO); 197.7 (d, 2J(P,C) = 34.8 Hz, trans-CO). 29Si{1H} NMR: δ −1.33 (d, 2J(P,Si = 5.5 Hz); 0.61 (d, 2J(P,Si) = 7.9 Hz). 31P{1H} NMR: δ 38.4 (1J(W,P) = 304.9 Hz). IR (KBr, selected data): ν̃ (cm−1) 937 (m), 1253 (s), 1381 (m), 1437 (m), 1620 (v), 1660 (v), 1913 (s), 2075 (s), 2903 (m), 2931 (m), 2955 (s); MS (EI, 184W): m/z 598.0 (20) [M]•+, 570.0 (10) [M − CO]+, 542.0 (5) [M − 2CO]+, 514.0 (20) [M − 3CO]+, 486.0 (100) [M − 4CO]+, 458.0 (45) [M − 5CO]+, 430.0 (45) [M − 4CO − C4H8]+, 402.0 (35) [M − 5CO − C4H8]+, 383.9 (55) [M − CH(Si(CH3)3)2 − C4H7]+, 358.0 (45) [M − 5CO − Si(CH3)3 − C4H7]+, 73.0 (70) [Si(CH3)3]+. Complex 14a. “Yield” of the mixture of 14a,b and 15 (75:16:9): 324 mg (0.51 mmol, 60%). Mp: 98 °C. Analytical data obtained from this mixture are as follows. 1H NMR: δ 0.02 (s, 9H, Si(CH3)3); 0.07 (s, 9H, Si(CH3)3); 1.10 (s, 1H, CH(Si(CH3)3)2); 2.84−3.09 (m, 2H, CH2); 3.28 (dd, 1H, 2+4J(H,H) = 5.4 Hz, 7.5 Hz, CH(P)(O)); 7.03− 7.08 (m, 1H, CH-Ar); 7.09−7.14 (m, 2H, CH-Ar); 7.20−7.26 (m, 2H, CH-Ar). 13C{1H} NMR: δ 1.1 (d, 3J(P,C) = 4.3 Hz, Si(CH3)3); 1.8 (d, 3J(P,C) = 2.3 Hz, Si(CH3)3); 30.7 (d, 1J(P,C) = 16.9 Hz, CH(Si(CH3)3)2); 37.9 (d, 2J(P,C) = 3.4 Hz, CH2); 60.5 (d, 1J(P,C) = 30.1 Hz, CH(P)(O)); 127.4 (s, CH-Ar); 129.1 (s, CH-Ar); 129.2 (s, CH-Ar); 137.1 (d, 3J(P,C) = 8.2 Hz, C−Ar); 195.9 (d, 2J(P,C) = 8.4 Hz, cis-CO); 196.2 (d, 2J(P,C) = 33.6 Hz, trans-CO). 29Si{1H} NMR: δ −1.88 (d, 2J(P,Si) = 4.9 Hz); −0.07 (d, 2J(P,Si) = 8.1 Hz). 31P{1H} NMR: δ 29.8 (1J(W,P) = 300.7 Hz). IR (KBr, selected data): ν̃ (cm−1) 726 (w), 1255 (s), 1454 (m), 1496 (m), 1930 (s), 1997 (s), 2077 (s), 2856−2924 (w), 2960 (s), 3034 (w). MS (EI, 184W): m/z 634.1 (3) [M]•+, 514.0 (40) [M − H − CO − C7H7]+, 488.0 (82) [M − 2Si(CH3)3] +,

486.0 (100) [M − H − 2CO − C7H7]+, 458.0 (25) [M − H − 3CO − C7H7]+, 430.0 (30) [M − H − 4CO − C7H7]+, 402.0 (21) [M − H − 5CO − C7H7]+, 383.9 (31) [M − 2Si(CH3)3 − CO − C6H5 + H]2+, 358.0 (31) [M − Si(CH3)3 − 4CO − C7H7]+, 193.1 (35) [C8H8O − Si(CH3)3]+, 91.0 (10) [C7H7]+, 73.0 (75) [Si(CH3)3]+. Anal. Calcd for C20H27O6PSi2W (634.4 g/mol): C, 37.86; H, 4.29. Found C 37.91; H, 4.44. Complex 14b. 31P{1H} NMR: δ 31.8 (1J(W,P) = 296.0 Hz). Crystal Data for 14a. Suitable single crystals of 14a were obtained from a concentrated n-pentane solution cooled to −20 °C. Data were collected with a Nonius KappaCCD diffractometer equipped with a low-temperature device at 100 K by using graphite-monochromated Mo Kα radiation (λ = 0.710 73 Å). The structure was solved by Patterson methods (SHELXS-97)13a and refined by full-matrix leastsquares on F2 (SHELXL-97).13b Crystal data: C20H27O6PSi2W, Mr = 634.4, colorless, crystal dimensions 0.12 × 0.10 × 0.01 mm3, triclinic, space group P1̅, Z = 2, a = 9.1156(9) Å, b = 10.8683(7) Å, c = 13.3557(13) Å, α = 77.712(6)°, β = 81.120(4)°, γ = 88.288(6)°, V = 1277.3(2) Å3, Dexptl = 1.649 g cm−3, μ = 4.708 mm−1, T = 123(2) K, transmission factors (minimum/maximum) 0.6019/0.9544, analytical absorption correction based on the indexing of the crystal faces, 2θmax = 54.0°, 5437 unique data, Rint = 0.0499, R1 (for I > 2σ(I)) = 0.0369, wR2 (for all data) = 0.0797, final R = 0.0369, goodness of fit 0.986, ΔF(maximum/minimum) = 1.693/−2.082 e Å−3.

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ASSOCIATED CONTENT

S Supporting Information *

A CIF file giving crystallographic data for 14a. This material is available free of charge via the Internet at http://pubs.acs.org. Crystallographic data of 14a have also been deposited at the Cambridge Crystallographic Data Centre under the file number CCDC 868282. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc. cam.ac.uk/data_request/cif.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Fax: (+) 49-228-73-9616. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We thank the Deutsche Forschungsgemeinschaft (STR 411/ 26-1) and the COST action CM0802 “PhoSciNet” for financial support. G.S. thanks Prof. A. C. Filippou for support.

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REFERENCES

(1) (a) Smith, J. D. Angew. Chem. 1998, 110, 2181−2183; Angew. Chem., Int. Ed. 1998, 3, 2071−2073. (b) Izod, K. Adv. Inorg. Chem. 2000, 50, 33. (c) Rabe, G. W.; Liable-Sands, L. M.; Rheingold, A. L. Inorg. Chim. Acta 2002, 329, 151−154. (d) Izod, K.; Stewart, J. C.; Cleggm, W.; Harrington, R. W. Dalton Trans. 2007, 257−264. (e) Pauer, F.; Power, P. P. In Lithium Chemistry: A Theoretical and Experimental Overview; Sapse, A. M., Schleyer, P. v. R., Eds.; Wiley: New York, 1994; p 361. (2) (a) Yoshifuji, M.; Shima, I.; Inamoto, N.; Hirotsu, K.; Higuchi, T. J. J. Am. Chem. Soc. 1981, 103, 4587−4589. (b) Couret, C.; Escudié, J.; Satgé, J. Tetrahedron Lett. 1982, 23, 4941−4942. (c) The term “phosphinidenoid” was first proposed in: Yoshifuji, M.; Sato, T.; Inamoto, N. Chem. Lett. 1988, 1735−1738. (3) (a) Schmidt, U. Angew. Chem. 1975, 87, 535−540. (b) Li, X.; Lei, D.; Chiang, M. Y.; Gaspar, P. P. J. Am. Chem. Soc. 1992, 114, 8526. (c) Li, X.; Weissman, S. I.; Lin, T. S.; Gaspar., P. P. J. Am. Chem. Soc. 1994, 116, 7899. (d) Bucher, G.; Borst, M. L. G.; Ehlers, A. W.; Lammertsma, K.; Ceola, S.; Huber, M.; Grote, D.; Sander, W. Angew. Chem., Int. Ed. 2005, 44, 3289−3293. 4714

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Organometallics

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(4) (a) Mathey, F.; Tran Huy, N. H.; Marinetti, A. Helv. Chim. Acta 2001, 84, 2938−2957. (b) Mathey, F. Angew. Chem. 2003, 115, 1616− 1643; Angew. Chem., Int. Ed. 2003, 42, 1578−1604. (c) Lammertsma, K. Top. Curr. Chem. 2003, 229, 95−119. (d) Aktas, H.; Slootweg, C. J.; Lammertsma, K. Angew. Chem. 2010, 122, 2148−2159; Angew. Chem., Int. Ed. 2010, 49, 2102−2113. (e) It should be noted that reaction of thermally generated electrophilic terminal phosphinidene complexes with α,β-unsaturated carbonyls or imines always leads to 1,4-addition products. For example, see: Marinetti, A.; Mathey, F. Organometallics 1984, 3, 456−461. (5) (a) Oezbolat, A.; Frantzius, G. v.; Perez, J. M.; Nieger, M.; Streubel, R. Angew. Chem., Int. Ed. 2007, 46, 9327. (b) Oezbolat, A.; Frantzius, G. v.; Hoffbauer, W.; Streubel, R. Dalton Trans. 2008, 2674. (6) For a P-C5Me5 substituted derivative of II (X = Cl), see: Bode, M.; Daniels, J.; Streubel, R. Organometallics 2009, 28, 4636. (7) Streubel, R.; Ö zbolat-Schö n, A.; Bode, M.; Daniels, J.; Schnakenburg, G.; Teixidor, F.; Vinas, C.; Vaca, A.; Pepoil, A.; Farras, P. Organometallics 2009, 28, 6031. (8) Nesterov, V.; Duan, L.; Schnakenburg, G.; Streubel, R. Eur. J. Inorg. Chem. 2011, 567−572. (9) Streubel, R.; Villalba Franco, J. M.; Schnakenburg, G.; Espinosa Ferao, A. Chem. Commun. 2012, 48, 5986−5988. (10) Pérez, J. M.; Klein, M.; Kyri, A.; Schnakenburg, G. Organometallics 2011, 30, 5636−5640. (11) Ö zbolat, A.; von Frantzius, G.; Pérez, J. M.; Nieger, M.; Streubel, R. Angew. Chem. 2007, 119 (48), 9488−9491; Angew. Chem., Int. Ed. 2007, 46 (48), 9327−9330. (12) Khan, A. A.; Wismach, C.; Jones, P. G.; Streubel, R. Chem. Commun. 2003, 12, 2892−2893. (13) (a) SHELXS-97: Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 46, 467. (b) Sheldrick, G. M. SHELXL-97; University of Göttingen, Göttingen, Germany, 1997.

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dx.doi.org/10.1021/om300177c | Organometallics 2012, 31, 4711−4715