ARTICLE pubs.acs.org/Organometallics
First Examples of Spirooxaphosphirane Complexes Janaina Marinas Perez, Melina Klein, Andreas Wolfgang Kyri, Gregor Schnakenburg, and Rainer Streubel* Institut f€ur Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universit€at Bonn, Gerhard-Domagk-Straße 1, 53121 Bonn, Germany
bS Supporting Information ABSTRACT: The reaction of a transient Li/Cl phosphinidenoid pentacarbonyltungsten complex (R = CH(SiMe3)2) with cyclohexanone, cyclopentanone, and cyclobutanone yielded the novel, atropisomeric spirooxaphosphirane complexes 3a,b 5a,b, while 2,3-diphenylcyclopropenone furnished selectively the 1,2-dihydrophosphet-2-one complex 6. All complexes have been characterized by heteronuclear NMR, mass spectrometry, and singlecrystal X-ray analysis in the case of 4a, 5a, and 6.
S
piroalkanes such as spiropentanes (I) have been intensively studied by experimentalists as well as theoreticians.1 Although spiroheterocycles are present in a large number of natural products2 and show physical properties of particular interest,3 the area of phosphorus-containing spiroheterocycles is deeply underdeveloped and, moreover, the research has been focused on phosphorus carbon ring systems4 such as the phospha-spiropentanes II IV (Scheme 1). Whereas most derivatives of II5,6 and III7 were bound to a transition-metal center,8 the only known derivative of IV9 (all tert-butyl substituted) was obtained nonligated. To the best of our knowledge, nothing is known about spiroheterocycles that have another heteratom (as in V) and, therefore, the question of the effect of a (very) polar ring bond on structure and reactivity has not been addressed before. Theoretical investigations on monocyclic oxaphosphirane derivatives revealed a considerable ring strain of 23.2 kcal/mol for the parent system (RI-CCSD(T)/TZVPP), while for trimethyloxaphosphirane pentacarbonylchromium(0) a slightly smaller mean value of 22.0 kcal/mol was obtained (RI-SCS-MP2/ TZVPP);10 this transition-metal effect was not studied further. Recent experimental studies on acid-induced ring opening11 of monocyclic oxaphosphirane complexes have demonstrated that they have become valuable new building blocks which deserve further study. On the basis of the convenient methodology for oxaphosphirane complexes that was developed recently,12 we felt attracted by the idea to establish a method that enables access to spiroheterocycles of type V as new ligand systems, which have various ring sizes and various heteroatoms E. Here, we report the facile synthesis of the first spirooxaphosphirane complexes (E = O) using the Li/Cl phosphinidenoid complex route and cyclic ketones. Furthermore, a first attempt to access a phospha-spiropentene complex derivative using this particular route is described.
’ RESULTS AND DISCUSSION Chlorine/lithium exchange in complex 1,13 using tert-butyllithium in the presence of 12-crown-4 at low temperature, led to the transient Li/Cl phosphinidenoid complex 2,12a which was r 2011 American Chemical Society
Scheme 1. Spiropentane (I), Phospha-Spiropentane Derivatives II IV, and Phospha-Spiroheterocycles Va
a
R denotes organic substituents, the dashed line in V indicates various ring sizes, and E indicates a heteroatom other than phosphorus.
reacted in situ with cyclohexanone, cyclopentanone, and cyclobutanone, thus yielding the spirooxaphosphirane complexes 3a,b 5a,b (Scheme 2). In all reactions the two isomers a and b were formed (3a,b, 23:77; 4a,b, 55:45; 5a,b, 69:31; determined via integration of the 31 1 P{ H} NMR spectra); only in the case of complexes 3a,b was the major isomer the b isomer, while in all other cases (4a,b and 5a,b) was the minor isomer. Column chromatography yielded only isomer 3b in pure form (see below), while the other complexes could not be separated and thus were purified and characterized as mixtures. Despite this, the structures of complexes 4a and 5a were unambiguously confirmed by single-crystal X-ray analysis; for selected data see Figures 1 and 2.
Received: May 23, 2011 Published: October 11, 2011 5636
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Organometallics
ARTICLE
Scheme 2. Synthesis of the Spirooxaphosphirane Complexes 3a,b 5a,b and Surprising Formation of the 1,2-Dihydrophosphet-2-one Complex 6
Figure 2. Molecular structure of complex 5a (two independent molecules in the crystal; 50% probability level; hydrogen atoms are omitted for clarity; because of great similarity only one data set is given). Selected bond lengths (Å) and angles (deg): W1 P1 = 2.4526(7), P2 W2 = 2.4743(7), C1 O1 = 1.477(3), C17 O7 = 1.469(3), C1 P1 = 1.779(3), C17 P2 = 1.776(3), C5 P1 = 1.796(3), C21 P2 = 1.807(3), O1 P1 = 1.674(2), O7 P2 = 1.6714(19); O1 P1 C1 = 50.53(11), O7 P2 C17 = 50.32(11), C1 O1 P1 = 68.42(14), C17 O7 P2 = 68.52(13).
Figure 1. Molecular structure of complex 4a in the crystal (50% probability level; 67% main orientation of the cyclopentane ring unit (solid line) and 33% (dashed line); only the crystallographic data of the main structure are given, as the second disordered structure is mainly the same; hydrogen atoms are omitted for clarity). Selected bond lengths (Å) and angles (deg): W P = 2.4781(10), P O1 = 1.666(3), C1 O1 = 1.492(5), P C1 = 1.795(4); P O1 C1 = 69.00(18), C1 P O1 = 50.92(16), O1 C1 P = 60.08(17).
In general, complexes 3a,b 5a,b showed phosphorus resonances between 31 and 58 ppm, in accordance with the values of monocyclic oxaphosphirane complexes.12b,c Within this series of spirooxaphosphirane complexes the trend became apparent that with decreasing ring size of the all-carbon ring unit the phosphorus resonance was shifted to higher field (Table 1). Complexes 3a,b 5a,b all showed similar 1J(W,P) values (292.5 296.3 Hz), although the values for the b isomers were most often slightly smaller. As the origination of the two isomers (of 3 5) was not apparent, we had the idea to test if atropisomerism might be responsible: i.e., a hindered rotation around the exo P C bond.14 Furthermore, we knew from crystal structures of azaphosphiridine complexes14 bearing this substituent (R1 = CH(SiMe3)2) that this group can adopt two orientations if sterically required: one with the CH group pointing toward the W(CO)5 group (“s-cis”, as in monocyclic oxaphosphirane
complexes)12b,c and one in which it points in the opposite direction (“s-trans”, as in azaphosphiridine complexes).15 Therefore, we carried out a temperature-dependent 31P{1H}NMR spectroscopic study using complexes 3a,b as a good case in point. Heating a toluene solution of a mixture (23:77, 25 °C) to 90 °C led to a ratio of 86:14, which did not change upon prolonged heating or subsequent cooling to 25 °C; coalescence was not observed. The 1H NMR spectrum of 3a, with a slight impurity of 3b (∼7%), revealed a significantly smaller 2J(P,H) coupling constant value for the exo CH proton (as compared to 3b), and thus this is in line with an “s-cis” conformation at the exo P C bond. It thus became apparent that there is a very good correlation between the size of this coupling constant value and the relative orientation of the CH(SiMe3)2 group: i.e., “s-cis” is the preferred conformation for oxaphosphirane derivatives with C-substituents of low or lower steric demand (such as complexes 4a and 5a, here) or other C-monosubstituted derivatives reported earlier. Therefore, it is in perfect agreement that the isomer ratios change if the steric demand changes. When the transient complex 2 was reacted with 2,3-diphenylcyclopropenone, the selective formation of the 1,2-dihydrophosphet-2-one complex 6 was observed (Scheme 2), but no evidence for the targeted unsaturated spirooxaphosphirane complex was obtained. Nevertheless, this points to a oxaspiropentene cyclobutenone rearrangement of an intermediate complex, which would be closely related to what was proposed by Mathey and Bertrand.16 In addition, the reaction pathway may include an acyclic intermediate in which the CH(SiMe3)2 group can freely rotate and thus find the thermodynamic sink. Complex 6, obtained in pure form after column chromatography, showed a phosphorus resonance at 91.5 ppm with a 1J(W,P) value of 230.2 Hz. Single-crystal X-ray diffraction analyses of complexes 4a and 5a (Figures 1 and 2) showed the presence of the R and S enantiomers in the unit cells. The structure of complex 4a was disordered in the cyclopentane unit (67:33). A general structural feature of both spiro compounds is the almost perpendicular arrangement of the oxaphosphirane ring plane and the planes defined by the spiro atom and its next neighboring carbon atoms 5637
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Organometallics Table 1.
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P, 1H, and 13C NMR Data (CDCl3) of Complexes 3a,b 5a,b
that the product ratio strictly depended on the steric demand of the all-carbon ring unit. Heating a solution of a mixture of 3a,b was used to bring about a change in the ratio of the two conformers. This also unveiled an interesting stereochemical feature of the CH(SiMe3)2 group, as it is able to behave in a binary manner. If 2,3-diphenylcyclopropenone was reacted with complex 1, the targeted product, a spirooxaphosphetene complex, was not observed, but the 1,2-dihydrophosphet-2-one complex 6 was obtained selectively, thus pointing to some kind of rearrangement reaction. Current studies aim at ring-opening reactions of spirooxaphosphirane complexes.
Figure 3. Molecular structure of complex 6 (50% probability level; hydrogen atoms are omitted for clarity). Selected bond lengths (Å) and angles (deg): W P = 2.5140(12), C3 P = 1.860(5), C2 C3 = 1.369(6), C2 C1 = 1.488(7), C1 P = 1.902(5), C4 P = 1.818(5), C1 O1 = 1.205(6); C3 P C1 = 70.9(2), C2 C1 P = 91.7(3), C3 C2 C1 = 99.5(4).
of the cyclopentane (4a) and cyclobutane ring (5a) (89.16 and 86.98°). In the case of complex 4a an envelope and in 5a a butterfly conformation was found. All complexes show an acute endocyclic angle at the phosphorus center (48 51°). Both complexes 4a and 5a display an “s-cis” conformation of the CH proton of the CH(SiMe3)2 group and the W(CO)5 group at the P C bond. The structure of complex 6 (Figure 3) confirmed that the phosphorus is part of a four-membered-ring system which is characterized by the C2 C3 distance (1.369(6) Å) and an acute angle at phosphorus (C1 P C3 = 70.9°).
’ CONCLUSIONS The reaction of transient Li/Cl phosphinidenoid complex 1 with cyclic ketones has enabled the synthesis of novel spirooxaphosphirane complexes that were obtained as mixtures of exoP C atropisomers. A detailed 31P{1H} NMR spectroscopic study, using complexes 3a,b as a good case in point, revealed
’ 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 and distilled under argon. NMR data were recorded on a Bruker DMX 300 spectrometer at 25 °C using CDCl3 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; selected data are given. Elemental analyses were performed by using an Elementar VarioEL instrument. Complexes 3a,b 5a,b. To a freshly prepared solution of complex 2 (261 mg, 0.47 mmol) in Et2O (6 mL) was added 3 equiv of the ketone (0.15 mL of cyclohexanone, 0.11 mL of cyclobutanone, 0.13 mL of cyclopentanone), and the reaction mixture was warmed to 0 °C. The solvents were removed in vacuo (∼10 2 mbar) and the products extracted with a 1:1 mixture of Et2O and n-pentane and purified by column chromatography (Al2O3, 30 °C, petroleum ether). The first fraction yielded pure 3b, while the second fraction yielded a mixture of both isomers 3a,b (or 4a,b or 5a,b) as a yellow oil. Complexes 4a,b (yield 155 mg (0.26 mmol, 55%)) and 5a,b (yield 107 mg (0.19 mmol, 39%)) were isolated as mixtures only. When a toluene solution of complexes 3a,b (c = 0.16 mol/L) was heated for 2 h at 90 °C, the ratio changed from 23:77 (25 °C) to 86:14. The product was purified by column chromatography (Al2O3, 20 °C, petroleum ether). During chromatography the percentage of diethyl ether was increased. The first fraction (1% Et2O) yielded 3b and 3a in a ratio of 93:7. The second fraction (5 10% Et2O) yielded 3b and 3a in a ratio of 37:63. 5638
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Organometallics 3a: yield of the mixture 168 mg (0.30 mmol, 58%) (analytical data obtained from a 93:7 mixture of 3a and 3b); 13C{1H} NMR δ 1.9 (d, 3J(P,C) = 4.3 Hz, Si(CH3)3), 2.3 (d, 3J(P,C) = 7.9 Hz, Si(CH3)3), 23.7 (d, 2,3,4J(P,C) = 7.9 Hz, CH2), 24.7 (d, 2,3,4J(P,C) = 2.8 Hz, CH2), 25.3 (s, CH2), 31.9 (s, CH2), 32.3 (d, 1J(P,C) = 17.7 Hz, CH(Si(CH3)3)2,), 34.4 (d, 2,3,4J(P,C) = 7.2 Hz, CH2), 67.3 (d, 1J(P,C) = 29.5 Hz, PCO), 196.1 (d, 2J(P,C) = 8.3 Hz, cis-CO), 196.2 (d, 2J(P,C) = 32.8 Hz, transCO); 31P{1H} NMR δ 57.7 (ssat, 1J(P,W) = 296.2 Hz); 1H NMR δ 0.26 (s, 9H, Si(CH3)3), 0.28 (s, 9H, Si(CH3)3), 1.29 (d, 1H, 2J(P,H) = 2.9 Hz, CH(Si(CH3)3)2), 1.58 1.87 (m, 8H, CH2), 1.87 1.98 (m, 2H, CH2); 29Si{1H} NMR δ 1.3 (d, 2J(P,Si) = 6.5 Hz, Si(CH3)3), 0.9 (d, 2 J(P,Si) = 8.3 Hz, Si(CH3)3). 3b: yield 30 mg (0.05 mmol, 10%); 13C{1H} NMR δ 2.0 (d, 3 J(P,C) = 4.9 Hz, Si(CH3)3), 2.1 (d, 3J(P,C) = 2.9 Hz, Si(CH3)3), 24.2 (d, 2,3,4J(P,C) = 5.5 Hz, CH2), 25.1 (d, 2,3,4J(P,C) = 2.2 Hz, CH2), 25.6 (d, 1J(P,C) = 38.8 Hz, CH(Si(CH3)3)2,), 25.7 (s, CH2), 31.1 (s, CH2), 34.9 (d, J(P,C) = 6.7 Hz, CH2), 67.9 (d, 1J(P,C) = 27.3 Hz, PCO), 196.1 (d, 2J(P,C) = 8.2 Hz, cis-CO), 196.8 (d, 2J(P,C) = 32.0 Hz, trans-CO); 31P NMR δ 47.1 (dqsat, 1J(P,W) = 295.6 Hz, 2J(P,H) = 14.8 Hz, 2J(P,H) = 12.6 Hz); 1H NMR δ 0.29 (s, 9H, Si(CH3)3), 0.34 (s, 9H, Si(CH3)3), 1.26 (d, 1H, 2J(P,H) = 15.9 Hz, CH(Si(CH3)3)2), 1.55 1.69 (m, 2H, CH2), 1.69 1.86 (m, 5H, CH2), 1.86 2.02 (m, 3H, CH2); 29Si{1H} NMR δ 1.5 (d, 2J(P,Si) = 5.8 Hz, Si(CH3)3), 4.0 (s, Si(CH3)3); MS m/z (EI) 612 (30) [M]•+, 584 (20) [M CO]•+, 556 (15) [M 2CO]•+, 514 (40) [M C6H10O] •+, 486 (15) [M CO C6H10O]•+, 73 (100) [Si(CH3)3]•+. Anal. Calcd for C18H29O6PSi2W (612.07 g/mol): C, 35.40; H, 4.77. Found: C, 35.15; H, 4.70. 4a (analytical data obtained from the mixture but assigned on the basis of the previous case study of 3a,b): 13C{1H} NMR δ 2.0 (d, 3J(P, C) = 4.4 Hz, Si(CH3)3), 2.3 (d, 3J(P,C) = 2.6 Hz, Si(CH3)3), 25.9 (d, 2,3J(P,C) = 3.7 Hz, CH2), 29.7 (d, 1J(P,C) = 8.7 Hz, CH), 33.1 (d, 2,3 J(P,C) = 1.3 Hz, CH2), 35.2 (d, 2J(P,C) = 7.9 Hz, CH2), 39.9 (s, CH2), 73.4 (d, 1J(P,C) = 31.4 Hz, ipso-C), 195.9 (d, 2J(P,C) = 8.4 Hz, cis-CO), 198.1 (d, 2J(P,C) = 32.5 Hz, trans-CO); 31P{1H} NMR δ 48.4 (ssat, 1J(P,W) = 296.3 Hz); 1H NMR δ 0.19 (s, 9H, Si(CH3)3), 0.22 (s, 9H, Si(CH3)3), 1.30 (d, 1H, 2J(P,H) = 4.2 Hz), 1.66 1.79 (m, 4H, CH2), 2.00 2.29 (m, 4H, CH2); 29Si{1H} NMR δ 1.3 (d, 2J(P,Si) = 6.4 Hz, SiMe3), 1.3 (d, 2J(P,Si) = 6.4 Hz, SiMe3). 4b (analytical data obtained from the mixture but assigned on the basis of the previous case study of 3a,b): 13C{1H} NMR δ 2.0 (d, 3J(P, C) = 3.6 Hz, Si(CH3)3), 2.0 (d, 3J(P,C) = 4.6 Hz, Si(CH3)3), 25.6 (d, 2,3J(P,C) = 4.2 Hz, CH2), 28.8 (d, 1J(P,C) = 37.7 Hz, CH), 33.2 (d, 2,3J(P,C) = 2.0 Hz, CH2), 34.7 (d, 2J(P,C) = 6.9 Hz, CH2), 38.5 (s, CH2), 74.7 (d, 1J(P,C) = 31.0 Hz, ipso-C), 196.9 (d, 2J(P,C) = 8.4 Hz, cis-CO), 196.5 (d, 2J(P,C) = 31.6 Hz, trans-CO); 31P{1H} NMR δ 36.2 (1J(P,W) = 293.7 Hz); 1H NMR δ 0.22 (s, 9H, Si(CH3)3), 0.26 (s, 9H, Si(CH3)3), 1.02 (d, 1H, 2J(P,H) = 16.8 Hz), 1.73 1.84 (m, 2H, CH2), 1.90 1.98 (m, 2H, CH2), 2.12 2.28 (m, 4H, CH2); 29Si{1H} NMR δ 1.2 (d, 2J(P,Si) = 5.6 Hz, SiMe3), 3.4 (d, 2J(P,Si) = 1.0 Hz, SiMe3); MS m/z (EI) 598 (5) [M]•+, 570 (10) [M CO]•+, 542 (10) [M •+ •+ 2CO] , 514.0 (40) [M C6H10O] , 486.0 (100) [M CO C6H10O]•+, 73 (95) [Si(CH3)3]•+. Anal. Calcd for C17H27O6PSi2W (598.06 g/mol): C, 34.12; H, 4.55. Found: C, 34.15; H, 4.52. 5a (analytical data obtained from the mixture but assigned on the basis of the previous case study of 3a,b): 13C{1H} NMR δ 2.0 (d, 2J(P, C) = 2.7 Hz, Si(CH3)3), 2.1 (d, 2J(P,C) = 4.4 Hz, Si(CH3)3), 13.7 (d, 2,3J(P,C) = 3.8 Hz, CH2), 31.0 (d, 1J(P,C) = 18.5 Hz, CH), 31.7 (s, CH2), 33.5 (d, 2,3J(P,C) = 4.3 Hz, CH2), 68.4 (d, 1J(P,C) = 23.6 Hz, ipso-C), 195.6 (d, 2J(P,C) = 8.6 Hz, cis-CO), 198.2 (d, 2J(P,C) = 32.9 Hz, trans-CO); 31P{1H} NMR δ 46.9 (1J(P,W) = 296.3 Hz); 1H NMR δ 0.22 (s, 9H, Si(CH3)3), 0.33 (s, 9H, Si(CH3)3), 1.33 (d, 1H, 2J(P,H) = 4.5 Hz, CH), 2.37 2.53 (m, 2H, CH2), 2.52 2.68 (m, 2H, CH2), 2.77 2.95 (m, 2H, CH2); 29Si{1H} NMR δ 1.3 (d, 2J(P,Si) = 5.4 Hz, SiMe3), 1.0 (d, 2J(P,Si) = 8.3 Hz, SiMe3).
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5b (analytical data obtained from the mixture but assigned on the basis of the previous case study of 3a,b): 13C{1H} NMR δ 1.9 (d, 2J(P, C) = 0.7 Hz, Si(CH3)3), 1.9 (d, 2J(P,C) = 2.3 Hz, Si(CH3)3), 13.4 (d, 2,3J(P,C) = 3.8 Hz, CH2), 28.7 (d, 1J(P,C) = 37.9 Hz, CH), 30.8 (s, CH2), 32.5 (d, 2,3J(P,C) = 2.8 Hz, CH2), 70.2 (d, 1J(P,C) = 23.1 Hz, ipso-C), 195.4 (d, 2J(P,C) = 8.2 Hz, cis-CO), 196.5 (d, 2J(P,C) = 31.9 Hz, trans-CO); 31P{1H} NMR δ 31.4 (ssat, 1J(P,W) = 292.5 Hz); 1H NMR δ 0.30 (s, 9H, Si(CH3)3), 0.31 (s, 9H, Si(CH3)3), 0.72 (d, 1H, 2J(P,H) = 17.4 Hz, CH), 1.83 2.07 (m, 2H, CH2), 2.36 2.52 (m, 2H, CH2), 2.59 2.70 (m, 2H, CH2); 29Si{1H} NMR δ 0.8 (d, 2J(P,Si) = 5.7 Hz, SiMe3), 3.6 (d, 2J(P,Si) = 1.6 Hz, SiMe3); MS m/z (EI) 584 (20) [M]•+, 556 (5) [M CO]•+, 528 (15) [M 2CO]•+, 514 (30) [M C4H6O]•+, 486 (100) [M CO C4H6O]•+, 458 (25) [M 2CO C4H6O]•+, 73 (90) [Si(CH3)3]•+. Anal. Calcd for C16H25O6PSi2W (584.04 g/mol): C, 32.89; H, 4.31. Found: C, 32.95; H, 4.32. Complex 6. To a freshly prepared solution of complex 2 (310 mg, 0.52 mmol) in Et2O (9 mL) was added 130 mg (0.63 mmol) of 2, 3-diphenylcyclopropenone, and the reaction mixture was warmed to ambient temperature. The solvent was removed in vacuo (∼10 2 mbar), and the product was extracted with 3 6 mL of n-pentane and purified by column chromatography (SiO2, 20 °C, petroleum ether/diethyl ether 9/1). Complex 6 was isolated as an orange solid: yield 237.9 mg (0.33 mmol, 63%); 13C{1H} NMR δ 2.4 (d, 3J(P,C) = 2.6 Hz, Si(CH3)3), 2.6 (d, 3J(P,C) = 2.6 Hz, Si(CH3)3), 26.4 (d, 1J(P,C) = 25.9 Hz, CH(SiMe3)2), 128.7 (s, Ph), 128.8 (s, Ph), 128.8 (s, Ph), 129.0 (s, Ph), 129.9 (s, Ph), 131.1 (s, Ph), 133.1 (s, Ph), 133.2 (s, Ph), 148.4 (d, 2J(P, C) = 53.7 Hz, PhCC(O)), 174.9 (d, 1,3J(P,C) = 25.9 Hz, PhCP), 195.3 (d, 2J(P,C) = 31.0 Hz, C(O)), 196.8 (d, 2J(P,C) = 5.8 Hz, cis-CO), 198.9 (d, 2J(P,C) = 23.9 Hz, trans-CO); 31P{1H} NMR δ 91.5 (1J(P,W) = 230.2 Hz); 1H NMR δ 0.02 (s, 9H, Si(CH3)3), 0.30 (s, 9H, Si(CH3)3), 1.38 (d, 2J(P,H) = 10.0 Hz, 1H, CH(Si(CH3)3)2), 7.24 (m, 3H, Ph), 7.39 (m, 5H, Ph), 7.64 (m, 2H, Ph); 29Si{1H} NMR δ 0.56 (d, 2J(P,Si) = 7.6 Hz, SiMe3); 1.48 (d, 2J(P,Si) = 4.7 Hz, SiMe3); MS m/z (EI) 720 (70) [M]•+, 664 (11) [M 2CO]•+, 647 (14) [M SiMe3]•+, 636 (20) [M 3CO]•+, 608 (100) [M 4CO]•+, 580 (25) [M 5CO]•+, 552 (50) [M 6CO]•+, 536 (30) [M 4CO SiMe3 + H+]•+, 506 (39) [M 5CO SiMe3 H]•+, 486 (70) [M CO C(Ph)C(Ph)(CO)]•+, 478 (40) [M 6CO SiMe3 H]•+, 458 (20) [M 2CO C(Ph)C(Ph)(CO)]•+, 434 (18) [M 5CO 2SiMe3]•+, 178 (20) [(Ph)CdC(Ph)]•+, 73 (100) [SiMe3]•+. Anal. Calcd for C27H29O6PSi2W (720.5 g/mol): C, 45.01; H, 4.06. Found: C, 44.00; H, 4.77. Crystal Data for 4a. Suitable single crystals of 4a were obtained from a concentrated n-pentane solution on cooling 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)17a and refined by full-matrix least squares on F2 (SHELXL-97):17b C17H27O6PSi2W, Mr = 598, colorless, crystal dimensions 0.600 0.220 0.200 mm3, monoclinic, space group P21/c, Z = 4, a = 9.2863(4) Å, b = 11.6174(4) Å, c = 21.6493(6) Å, β = 95.300(2)°, V = 2325.60(14) Å3, Dexptl = 1.709 g cm 3, μ = 5.166 mm 1, T = 123(2) K, transmission factors (min/max) 0.214 25/0.331 16, analytical absorption correction based on the indexing of the crystal faces,15 2θmax= 54.0°, 4952 unique data, Rint = 0.0510, R1 (for I > 2σ(I)) = 0.0282, wR2 (for all data) = 0.0624, final R = 0.0282, goodness of fit 0.979, ΔF(max/min) = 1.259/ 1.306 e Å 3. Crystal Data for 5a. Suitable single crystals of 5a were obtained from a concentrated n-pentane solution on cooling 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)17a and refined by full-matrix least squares on F2 (SHELXL-97):17b C16H25O6PSi2W, Mr = 584, colorless, 5639
dx.doi.org/10.1021/om200431f |Organometallics 2011, 30, 5636–5640
Organometallics crystal dimensions 0.480 0.440 0.420 mm3, triclinic, space group P1, Z = 4, a = 10.7439(3) Å, b = 15.2447(3) Å, c = 16.2191(4) Å, α = 113.9990(12)°, β = 102.9220(13)°, γ = 99.5701(13)°, V = 2264.55(10) Å3, Dexptl = 1.714 g cm 3, μ = 5.303 mm 1, T = 123(2) K, transmission factors (min/max) 0.0937/0.1077, analytical absorption correction based on the indexing of the crystal faces,17 2θmax= 5460°, 10 633 unique data, Rint = 0.0493, R1 (for I > 2σ(I)) = 0.0241, wR2 (for all data) = 0.0585, final R = 0.0241, goodness of fit 1.015, ΔF(max/min) = 1.087/ 1.490 e Å 3. Crystal Data for 6. Suitable single crystals of complex 6 were obtained from a concentrated n-pentane solution on cooling 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)17a and refined by full-matrix least squares on F2 (SHELXL-97):17b C27H29O6PSi2W, Mr = 721, colorless, crystal dimensions 0.60 0.60 0.40 mm3, monoclinic, space group P21/n, Z = 4, a = 9.4702(4) Å, b = 11.4948(5) Å, c = 27.2741(12) Å, α = 90°, β = 97.782(2)°, γ = 90°, V = 2941.7(2) Å3, Dexptl = 1.627 g/cm3, μ = 4.100 mm 1, T = 123(2) K, transmission factors (min/max) 0.1923/ 0.2908, analytical absorption correction based on the indexing of the crystal faces, 2θmax = 56.0°, no. of unique data 7097, Rint = 0.0507, R1 (for I > 2σ(I)) = 0.0459, wR2 (for all data) = 0.1064, final R = 0.0429, goodness of fit 1.135, ΔF(max/min) = 3.59/ 2.740 e Å 3. Crystallographic data for 4a, 5a, and 6 have been deposited at the Cambridge Crystallographic Data Centre under the numbers CCDC 806111(4a), CCDC 806112 (5a), and CCDC 806113 (6). These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
’ ASSOCIATED CONTENT Supporting Information. CIF files giving crystallographic data for 4a, 5a, and 6. This material is available free of charge via the Internet at http://pubs.acs.org.
bS
’ AUTHOR INFORMATION Corresponding Author
ARTICLE
(5) Hung, J.-T.; Yang, S.-W.; Gray, G. M.; Lammertsma, K. J. Org. Chem. 1993, 58, 6786. (6) A P-imino derivative of I having a σ4,λ5-phosphorus was reported by: Barion, D.; David, G.; Link, M.; Niecke, E. Chem. Ber. 1983, 126, 649. (7) (a) Weber, L.; L€ucke, E.; Boese, R. Organometallics 1988, 7, 978. (b) A 1,4-diphosphaspiropentane ligand was described by: Tran Huy, N. H.; Salemkour, R.; Bartes, R.; Ricard, L.; Mathey, F. Tetrahedron 2002, 58, 7191. (8) A derivative of I is also known in a nonligated fashion if embedded in a phospha[7]triangulane; see: Slootweg, J. C.; Schakel, M.; de Kanter, F. J. J.; Ehlers, A. W.; Kozhkushkov, S. I.; de Meijere, A.; Lutz, M.; Spek, A. L.; Lammertsma, K. J. Am. Chem. Soc. 2004, 126, 3050. (9) Baudler, M.; Leonhardt, W. Angew. Chem., Int. Ed. Engl. 1983, 22, 632. (10) Krahe, O.; Neese, F.; Streubel, R. Chem. Eur. J. 2009, 15, 2594. (11) (a) Perez, J. M.; Helten, H.; Donnadieu, B.; Reed, C.; Streubel, R. Angew. Chem., Int. Ed. 2010, 49, 2615. (b) Perez, J. M.; Albrecht, C.; Helten, H.; Schnakenburg, G.; Streubel, R. Chem. Commun. 2010, 46, 7244–7246. € (12) (a) Ozbolat, A.; von Frantzius, G.; Perez, J. M.; Nieger, M.; Streubel, R. Angew. Chem., Int. Ed. 2007, 46, 9327. (b) For oxaphosphirane W(CO)5 complexes, see: Bode, M.; Perez, J. M.; Schnakenburg, G.; Daniels, J.; Streubel, R. Z. Anorg. Allg. Chem. 2009, 635 (8), 1163. (c) For oxaphosphirane Cr(CO)5 and Mo(CO)5 complexes, see: Albrecht, C.; Bode, M.; Perez, J. M.; Schnakenburg, G.; Streubel, R. Dalton Trans. 2011, 40, 2654. (13) Khan, A. A.; Wismach, C.; Jones, P. C.; Streubel, R. Dalton Trans. 2003, 12, 2483. (14) For example, atropisomerism in P-heterocyclic ligands has been observed before in 2H-1,2,4-diazaphosphole complexes; see: Streubel, R.; Schiemann, U.; Tran Huy, N. H.; Mathey, F. Eur. J. Inorg. Chem. 2001, 3175. (15) Fankel, S.; Helten, H.; von Frantzius, G.; Schnakenburg, G.; Daniels, J.; Chu, V.; M€uller, C.; Streubel, R. Dalton Trans. 2010, 39, 3472. (16) Tran Huy, N. H.; Donnadieu, B.; Bertrand, G.; Mathey, F. Organometallics 2010, 29, 1302. (17) (a) SHELXS-97: Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 46, 467. (b) Sheldrick, G. M. SHELXL-97; University of G€ottingen: G€ottingen, Germany, 1997.
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’ ACKNOWLEDGMENT We are grateful to the Deutsche Forschungsgemeinschaft (STR 411/29-1) and the COST action cm0802 “PhoSciNet” for financial support; we are also thankful to Carolin Albrecht for measuring the temperature-dependent NMR spectra in the case of complexes 3a,b. ’ REFERENCES (1) Review: de Meijere, A.; Kozhushkov, S. I. Chem. Rev. 2000, 100, 93. (2) (a) Perron, F.; Albizati, K. F. Chem. Rev. 1989, 89, 1617. (b) Heathcock, C. K.;, Graham, S. L.; Palvac, F. P.; White, C. T. In Total Synthesis of Natural Products; Simon, J., Ed.; Wiley: New York, 1983; Vol. 5, p 264. (3) (a) Pudzich, R.; Fuhrmann-Lieker, T.; Salbeck, J. Adv. Polym. Sci. 2006, 199, 83. (b) Gleiter, R.; Hoffmann, H.; Irngartinger, H.; Nixdorf, M. Chem. Ber. 1994, 127 (11), 2215. (c) Lukyanov, B. S.; Lukyanova, M. B. Chem. Heterocycl. Compd. 2005, 41 (3), 281. (4) (a) Baudler, M. Pure Appl. Chem. 1980, 52, 755. (b) Baudler, M. Angew. Chem., Int. Ed. Engl. 1982, 21, 492. (c) Mathey, F. Chem. Rev. 1990, 90, 997. (d) Mathey, F., Ed. Phosphorus-Carbon Heterocyclic Chemistry: The Rise of a New Domain; Elsevier: Oxford, U.K., 2001. (e) Mathey, F. Angew. Chem. 2003, 115, 1616. 5640
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