2091
Organometallics 1995, 14,2091-2101
Generation of (2,3-q)-Naphthalyne-Nickel(0) Complexes and Their Reactions with Unsaturated Molecules Martin A. Bennett,* David C. R. Hockless, and Eric Wenger Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia Received November 2, 1994@ Sodium-amalgam reduction of the (3-bromonaphthyl)nickel(II)complexes NiBr(3-Br-2CloHdLz gives the first monomeric nickel(0) complexes of 2,3-naphthalyne, Ni(q2-C1oH6)L2 (2 L = 2 PEt3 (2), dcpe (5); dcpe = 1,2-bis(dicyclohexylphosphino)ethane,Cy2PCH2CH2PCy2). Complex 2 undergoes double-insertion reactions with dimethyl acetylenedicarboxylate (DMAD)or diphenylacetylene to give 1,2,3,44etrasubstituted anthracenes, C14H6R4 (R = CO2Me (8), P h (9)). Complex 5 reacts with C02 and with C2F4 to give isolable products of
v
I
monoinsertion into the naphthalyne-nickel(0) bond, Ni(3-CloH&00-2)(dcpe) (6) and Ni(3I
C I O H ~ C F ~ C F ~ -(71, ~ ) respectively, ( ~ C ~ ~ ) and 7 undergoes further insertion with DMAD to
give Ni{ ~ - C ( C O ~ M ~ ) = C ( C O ~ M ~ ) C I O H ~(10). C F ~The ~ F structures ~ - ~ ) ( ~ofC6, ~ 7~,)and 10 have been solved by heavy-atom methods and refined by least-squares methods. Crystal data: 6, space group P21In (No. 14), a = 14.714(2) b = 17.100(1) c = 15.990(2) A, p = 110.244(9)",2 = 4, 2997 observed reflections ( I > 341))with R = 4.1 and R, = 2.8; 7, space group P21Ic (No. 14), a = 11.139(2) b = 19.557(2) c = 16.809(2) p = 92.927(9)", 2 = 4, 3872 observed reflections ( I > 340)with R = 3.5 and R, = 2.9; 10, space group Pi (No. 2), u = 9.415(3) b = 11.759(2)A, c = 20.218(3) a = 93.94(1)", ,8 = 94.77(2)", y = 108.90(2)", 2 = 2, 4432 observed reflections (I > 3 d ) ) with R = 3.6 and R, = 3.0.
A,
A,
A, A, A,
A, A,
Introduction
Results and Discussion
We have shown that monomeric nickel(0)-benzyne complexes Ni(4,5-R2-(1,2-)7)-CsH2)L2(R = H,F; 2 L = 2 PEt3, dcpe),' which can be prepared by alkali-metal reduction of the corresponding (2-halogenoary1)nickel(11) complexes Ni(2-X-4,5-R2CsH2)Lg,2-4 react with various alkynes to form substituted naphthalene^.^ In this reaction the alkyne is believed to undergo double insertion into the nickel-benzyne bond to form an undetected benzonickelacycloheptatriene, which reductively eliminates the naphthalene and forms NiL2 (Scheme 1). For some unsymmetrical acetylenes, e.g. t-BuC2H and MeC2C02Me, good regioselectivity was observed, as a possible consequence of control by steric and electronic effects, respectively, on the sequential insertion^.^ In this paper we show that 2,3-naphthalyne complexes of nickel(0) can be generated similarly to their benzyne analogues and make some preliminary observations on their reactivity. Free 2,3-naphthalyne has been generated previously by the action of phenyllithium on 2,3-dibromonaphthalene and trapped by cycloaddition with 2-methylisoindole and with furan.
The syntheses of the (2,3-)7)-naphthalyne complexes are outlined in Scheme 2. Oxidative addition of 2,3dibromonaphthalene to Ni(COD)2 in the presence of triethylphosphine (2 equiv) gave a good yield of of the (3-bromonaphthyl)nickel(II)complex NiBr(3-Br-2-CloH& (PEt3)2(11,which, in contrast with the (2-bromophenyl)nickel(I1) ~omplexes,~ was not reactive toward lithium. Reduction of 1 with 1%N a g gave the required (2,3Vhaphthalyne cqmplex Ni(q2-CloHs)(PEt3)2(21, which was isolated in 90% yield as a highly air-sensitive, oily, yellow solid from hexane at -78 "C. The FAB mass spectrum of 2 in tetraglyme shows the compound to be monomeric, and the IR spectrum contains a strong band at 1585 cm-l, which, like the corresponding band in the benzyne-nickel(0) c ~ m p l e x e s ,is~assigned ,~ tentatively to v(CN!) modified by coordination. In addition t o the signals due to PEt3, there are three two-proton resonances in the lH NMR spectrum: a pair of AA'BB' multiplets due t o H6,7and H5r8and a singlet due to H1,4 whose chemical shifts are close to those of free naphthalene. Thus, the aromatic ring is not greatly affected by the presence of the coordinated triple bond, consistent with the presence of a weak additional bond perpendicular to the n-system.6-8 In agreement, the 13C NMR spectrum shows four resonances in the usual aromatic region together with a singlet at 6 142.52, which is assigned to the bound carbon atoms (C2a)of the naphthalyne. As in the case of the corresponding
Abstract published in Advance ACS Abstracts, March 1, 1995. (1)Abbreviations: dcpe = 1,2-bis(dicyclohexylphosphino)ethane, CyzPCHzCHzPCyz; COD = 1,5-cyclooctadiene, C8H12; dppe = l,2-bis(diphenylphosphinokthane; DMAD = dimethyl acetylenedicarboxylate, Cz(CO2Me)Z;AIBN = azobis(isobutyronitrile),C ~ H ~ Z N ~ . (2) Bennett, M. A.; Hambley, T. W.; Roberts, N. K.; Robertson, G. B. Organometallics 1985, 4 , 1992. (3)Bennett, M. A.; Griffiths, K. D.; Okano, T.; Parthasarathi, V.; Robertson, G. B. J . Am. Chem. SOC.1990,112, 7047. (4) Bennett, M. A.; Wenger, E. Organometallics, in press. (5)LeHoullier, C. S.; Gribble, G. W. J . Org. Chem. 1983, 48, 2364. @
(6) Hoffmann, R. W. Dehydrobenzenes and Cycloalkynes;Academic Press: New York, 1967. ( 7 ) Hoffmann, R. W. In Chemistry ofAcetylenes; Viehe, H. G., Ed.; Marcel Dekker: New York, 1969; Chapter 16, p 1063. ( 8 ) Gilchrist, J. L. In The Chemistry ofFunctiona1 Groups; Patai, S., Rapoport, Z., Eds.; Wiley: New York, 1983;Suppl. C, part 1, p 383.
0276-7333/95/2314-2091$09.00/00 1995 American Chemical Society
Bennett et al.
2092 Organometallics, Vol. 14, No. 4, 1995 Scheme 1"
@R
0 1-Ni
Ni R
RGC-R
i + NNO)
Phosphine ligands omitted for clarity.
Scheme 2 Na/Hg 2 PEt3
a : . P E t 3 Et$''
*Br
1
Na/Hg
CY2P'
CY2
u
'KY2
5
4
Ni(y2-benzyne)(PEt3)2complexes, the last resonance shows no 31Pcoupling at room temperature, owing t o rapid intermolecular exchange with traces of residual PEt3. Chemical evidence for the formulation of 2 as a (2,3-y)-naphthalynecomplex is provided by the reaction with DC1, which gives NiC12(PEt& and 2,3-dideuterionaphthalene quantitatively. The latter was the only isomer present, as shown by GC-MS and NMR (lH, 13C) spectroscopy. The 13C resonances belonging to carbon atoms C1 and C4 showed a typical isotropic shift (0.2 ~ p m )hence, ;~ the deuterium atoms must be attached to carbon atoms C2 and C3. The reaction of 2,3-dibromonaphthalene with NiBrz(PPh& in the presence of zinc that had been sonicated gave the (3-bromonaphthyl)nickel(II)complex NiBr(3Br-2-CloH6)(PPh& (31,which when heated with dcpe (4) in 64% yield. Like gave NiBr(3-Br-2-CloHe)(dcpe) 1 , 4 was unaffected by lithium but was reduced by 1% N a g , giving the (2,3-y)-naphthalynecomplex Ni(y2CloHddcpe) (5) as a beige-yellow, air-sensitive solid in 44% yield. The chemical shifts of the aromatic protons and of the carbon atoms in 5 are similar to those of 2; the bound carbon atoms C2n3 appear at 6 144.4-144.9 as a poorly resolved AAX multiplet similar t o that observed in Ni(y2-C6H4)(d~pe).2In the 31P{'H} NMR spectrum there is a sharp singlet at 6 77.3 (cf, 6 77.6 in Ni(y2-CsH4)(dcpe)).2 (9)Giinther, H.NMR Spectroscopy, An Introduction; Wiley: New York, 1980;pp 361-363.
The naphthalyne complexes have been characterized further by their insertion reactions with small molecules (Scheme 3). Complex 5 reacted with C02 to give Ni(3I
CloH&00-2)(dcpe) (61, which was isolated in 25% yield as a yellow solid. It shows a parent ion in its FAB mass spectrum and characteristic carboxylate bands at 1632 and 1615 cm-l in its IR spectrum; similar bands have
been observed in the IR spectra of Ni(CsH4CoO)(d~pe)~
n
and ~(CsH4C00)(y5-CsHs)2.10 The 31P{'H} NMR spec~ 25.0 Hz) arising trum consists of an AB quartet ( 2 J p = from cis-inequivalent phosphorus atoms, and the 13C NMR spectrum contains a doublet of doublets at 6 150.24 assigned to the o-bonded carbon atom C2,which is coupled to the two phosphorus atoms. There are also resonances assignable to the remaining aromatic carbon atoms and to the CH and CHZ groups of coordinated dcpe, but the carbonyl 13C resonance could not be located.
A similar insertion product, Ni(3-CloH6CF~kF2-2)(dcpe) (71, was obtained in 75% yield by reaction of 5 with tetrafluoroethylene at -60 "C with subsequent warming to room temperature. These conditions are considerably milder than those necessary for the cor(10)( a ) Kolomnikov, I. S.; Lobeeva, T. S.; Gorbachevskaya, V. V.; Aleksandrov, G. G.; Struchkov, Yu.T.; Vol'pin, M. E. J.Chem. SOC.D 1971,972.(b)Kolomnikov, I. S.; Lobeeva, T. S.;Vol'pin, M. E. J.Gen. Chem. USSR (Engl. Transl.) 1972,42,2229.
Organometallics, Vol. 14, No. 4, 1995 2093
(2,3-r,+Naphthalyne-Nickel(O) Complexes
Scheme 3 0
6
'\gh
= dcpe)
b
2L ZPEt, (2) 2L = dcpe (5)
R
R = CQMe (8) R = Ph (9)
" 7 2 L = dcpe)
L
L
7
R = C02Me (10)
responding insertion of the less electrophilic olefin ethylene with Ni(y2-CsH4)(dcpe)(3 bar, 80 "C).2 The 31P{ lH} NMR spectrum shows a pair of multiplets arising from P-F coupling: one phosphorus atom is coupled to all the fluorine atoms; the other is coupled only to the fluorine atoms of the Ni-CF2 group. The P-P coupling constant of 14.5 Hz confirms that the phosphorus atoms are mutually cis. Correspondingly, the 19FNMR spectrum of 7 shows a broad signal and a multiplet of equal intensity in the region 6~ -100 correspondingto the two different CF2 groups. The structures assigned t o 6 and 7 have been confirmed by single-crystal X-ray structural analyses (see below). Dimethyl acetylenedicarboxylate (DMAD) reacted with 2 at -30 "C to give a 16% isolated yield of tetramethyl 1,2,3,4-anthracenetetracarboxylate, C14HS(C02Me)4 (81, together with a small amount of hexamethyl benzenehexacarboxylate, Cs(CO2Me)s, arising from cyclotrimerization. The former is probably formed by a double-insertion sequence similar to that shown in Scheme 1 for Ni(y2-CsH4)L2,and the 31P{1H}NMR spectrum of the reaction mixture showed a peak at 6 26.6, which may be due to Ni(y2-DMAD)(PEt3)2formed after reductive elimination of 8 from the coordination sphere. A similar reaction occurred, though much more slowly, on treatment of 2 with diphenylacetylene. After (9) was 6 days a t 60 "C, 1,2,3,4-tetraphenylanthracene obtained in 17% isolated yield. In neither case could intermediate monoinsertion complexes analogous to those formed from Ni(y2-CsHddcpe)or Ni(4,5-F2-1,27CsHz)(dcpe)and DMAD be detected. Dimethyl acetylenedicarboxylate also reacted with the C2F4 insertion product 7 in refluxing THF to give the
seven-membered nickelacycle Ni{ 3-C(COzMe)=C(COzMe)CloH&FzCFz-2}(dcpe) (10) as a yellow solid in 37% isolated yield. No organic products arising from reductive elimination or possible multiple insertion followed by reductive elimination were detected. In addition t o the usual aromatic and dcpe resonances, the lH NMR spectrum of 10 shows a pair of singlets at 6 3.58 and 3.74 due to the inequivalent COzMe groups. In the 19F NMR spectrum there are four 19F- and 31P-coupled resonances in the region 6 -120 to -70, which indicate that all four fluorine atoms are inequivalent and suggest that the chelate ring is not planar, in agreement with the structure determined by X-ray crystallography (see below). The 31P{1H}NMR spectrum consists of a pair of lgF-coupledmultiplets with 2 J p p = 27.0 Hz, showing that the complex, like its precursor, has cis-phosphorus atoms. The existence of strong P-F coupling is in accord with the proposed structure and rules out the alternative derived by insertion of DMAD into the NiCF2 bond.
Molecular Structures of Ni(3-C1&COO-2)(dcpe> I 1
I
(61, Ni(S-CloHsCF2CF2-2)(dcpe) (7),and Ni{3-C(COz-
Me)=C(C02Me)Cl0H&FzCFz-2}(dcpe) (10). These are shown in Figures 1-3, respectively; the respective atomic coordinates are in Tables 1-3, and selected bond lengths and interbond angles are given in Tables 4-6, respectively. In all cases the coordination geometry about nickel is close to square planar. In 6 the a-bonded aryl carbon atom C2 and the oxygen atom 0 2 of the fivemembered chelate ring are twisted slightly out of the coordination plane by 0.214 and -0.125 A, respectively. The Ni-0 distance (1.900(3)A) is similar to the corre-
Bennett et al.
2094 Organometallics, Vol. 14, No. 4, 1995
atoms have been
Figure 1. ORTEP omitted for clarity.
CU
Figure 2. ORTEP diagram for 7 with atom labeling and with 50% probability ellipsoids. Hydrogen atoms have been omitted for clarity.
sponding value of 1.877(9)
A
found in the sevenI
I
and in NiEt(acac)NiMe(acac)(PCya) (1.881, 1.896 (PPh3) !1.909(9), 1.913(9) A).13 The C=O distance
membered-ring nickelacycle Ni(CHzCMe~C~H~CO02)-(PMe3)211 and t o the distances observed in of 1.235(5)
A
(cf.
1.222(16)
A
7
in Ni(CHzCMe2-
Organometallics, Vol. 14,No.4, 1995 2095
(2,3-q)-Naphthalyne-Nickel(O)Complexes
c35
Figure 3. ORTEP diagram for 10 with atom labeling and with 50% probability ellipsoids. Hydrogen atoms have been omitted for clarity.
0C.L
1 1
electron donation from the phosphorus atoms via the nickel atom to the C - 0 n*-orbital of the ester group. Complex 7 contains an envelope-shaped five-membered metallacycle derived by insertion of C2F4 into the nickel-benzyne bond of 5; the nickel atom is 0.750 A out of the plane formed by C2-C3-C9-C10. Complex 10 contains a boat-shaped seven-membered metallacycle derived by insertion of DMAD into the nickel-aryl bond Of 7, the angle between the planes formed by Ni-C10C12 and C9-ClO-Cll-Cl2 being 38.5", as illustrated in Figure 4. This geometry renders the four fluorine atoms chemically inequivalent, in agreement with the NMR results (see above). A similar conformation has
r
been reported for the seven-membered nickelacycle Ni-
-
(CH2CMe2C6H4COO-2)(PMe3)2.11 The Ni-CF2 bond
lengths in 7 and 10, 1.926(3) and 1.955(4) A, respectively, are close t o the value of 1.948(6) A reported for
Figure 4. Side view of complex 10 showing the boat conformation of the metallacycle. Hydrogen atoms and cyclohexyl groups of the dcpe ligand have been omitted for clarity.
C6H4C00-2)(PMe3)2)11is slightly greater than the typical values for an uncoordinated aryl ester (1.202 A) or for a y-lactone (1.198 A),14 whereas the 0-CO bond length (1.307(5)A)appears to be significantly less than those in aryl esters and lactones (1.337 A and 1.350 A, respective1y).l4 These trends may be a consequence of (11)(a) Carmona, E.; Palma, P.; Paneque, M.; Poveda, M. L.; Gutierrez-Puebla, E.; Monge, A. J. Am. Chem. SOC.1986, 108,6424. (b) Carmona, E.; Gutierrez-Puebla, E.; Marin, J. M.; Monge, A.; Paneque, M.; Poveda, M. L.; Ruiz, C. J . Am. Chem. SOC.1989, 1 1 1 , 2883. (12)Barnett, B. L.; Kriiger, C. J. Organomet. Chem. 1972,42, 169. (13)Cotton, F. A.; Frenz, B. A,; Hunter, D. L. J . Am. Chem. SOC. 1974,96, 4820.
the five-membered nickelacycle Ni(CF2(CF2)2CF2}(PEt&l5 and are somewhat less than the Ni-CH2 separations in Ni(C6H4CHzCH2-2)(dcpe)(1.988(12) A)2 and Ni(CsH.&MezCH2-2)(PMe3)2(1.97(1) this trend has been observed previously in comparable alkyl- and perfluoroalkyl-transition-metal complexes.16 The nickel-aryl bond lengths in 6,7, and 10 fall in the range 1.93-1.95
A
7
and are similar to that in Ni(CgH4-
CMe2CH2)(PMe3)2.11bThe Ni-P distances trans to the various a-bonded carbon atoms in 6, 7, and 10 are in the range 2.17-2.21
A
(cf. 2.218(2)
A
7
in Ni(CF2-
(14) Schweizer, W. B.; Dunitz, J. D. Helu. Chim.Acta 1982,65,1547. (15) Burch, R. R.; Calabrese, J. C.; Ittel, S. D. Organometallics 1988, 7, 1642.
(16)Hughes, R. P. Adu. Organomet. Chem. 1990, 31, 183 and references cited therein.
-
2096 Organometallics, Vol. 14, No. 4, 1995
Table 1. Atomic Coordinates for
Bennett et al.
Table 2. Atomic Coordinates for
I
Ni(3-C,oH&F2CF2-2)(dcpe) (7)
Ni(3-CloHsC00-2)(dcpe) (6) atom
X
v
7
atom
X
v
7
Ni 1 CK 1) CK2) PI P2 01 02
0.77099(6) 0.6 14x2) 0.4384( I ) 0.87131( IO) 0.80959( IO) 0.5708(3) 0.6762(2) 0.5206(5) 0.7826(3) 0.7428(3) 0.668 l(3) 0.6736(4) 0.6335(3) 0.6418(4) 0.6875(4) 0.7659(5) 0.7965(4) 0.75 14(4) 0.6333(4) 0.9076(4) 0.9160(4) 0.8439(3) 0.9127(4) 0.9265(5) 0.9637(5) 0.9008(5) 0.8843(4) 0.7248(4) 0.68 13(4) 0.61 19(5) 0.5369(5) 0.5804(5) 0.6456(4) 0.8150(4) 0.7167(4) 0.6635(4) 0.7252(5) 0.8225(5) 0.8772(4) 0.9855(4) 1.0085(4) I .0960(4) I . I839(4) I . 163814) 1.0757(4)
0.24022(5) 0.3572( 1) 0.2759( I ) 0.16905(8) 0.17296(8) 0.3951(2) 0.2958(2) 0.34 16(5) 0.3275(3) 0.3121(3) 0.3640(3) 0.4384(3) 0.4230(3) 0.5012(3) 0.5 177(3) 0.47 I I(4) 0.4094(3) 0.3912(3) 0.3530(3) 0.0860(3) 0. I 122(3) 0.2404(3) 0.3046(3) 0.3655(4) 0.3290(5) 0.2638(4) 0.2020(3) 0.1044(3) 0.0461(3) -0.01 2 l(4) 0.0282(4) 0.0843(4) 0.1447(4) 0.1253(3) 0.0895(3) 0.0594(4) 0.0015(4) 0.037 l(4) 0.0680(3) 0.215 l(3) 0.2912(3) 0.3326(3) 0.2807(4) 0.2044(4) 0.1618(3)
0.18495(5) 0.4300(2) 0.3464(2) 0.14850(9) 0.31 155(9) 0.1754(2) 0.2 I70(2) 0.3332(5) 0.0207(3) 0.0857(3) 0.0871(3) -0.0391(3) 0.0277(3) -0.1009(4) -0. I59 l(4) -0.1608(4) -0.1031(4) -0.0408(3) 0.1636(3) 0.2267(3) 0.32 lO(3) 0.4064(3) 0.3985(4) 0.4718(5) 0.5635(5) 0.5725(4) 0.4985(4) 0.3343(4) 0.2584(4) 0.2783(5) 0.3056(6) 0.381 l(5) 0.3569(5) 0.0372(3) 0.0281(4) -0.0662(4) -0.095 l(4) -0.0865(4) 0.0082(4) 0.148 l(3) 0.201 l(4) 0.1907(4) 0.2200(5) 0.1694(5) 0.1804(4)
Ni I PI P2 FI F2 F3 F4
0.10269(5) 0.24452(8) -0.0 1045(7) 0.2151(2) 0.2224(2) 0.3270(2) 0.1777(2) -0.1416(3) -0.0 170(3) 0.0333(3) -0.0323(4) -0.1590(4) -0.2327(4) -0.3539(5) -0.4094(4) -0.3415(4) -0.2 142(3) 0.1674(3) 0.2007(3) 0.3709( 3) 0.3392(3) 0.4443(4) 0.4906(4) 0.5256(4) 0.4204(3) 0.3 162(3) 0.3968(3) 0.4554(4) 0.3622(4) 0.2818(4) 0.2225(3) 0.1734(3) 0.0865(3) -0.0728(3) 0.0234(3) -0.0267(3) -0.0775(3) -0.1748(3) -0.1278(3) -0.1383(3) -0.1259(3) -0.2388(3) -0.2649(3) -0.2760(3) -0.1652(3)
0.23883(3) 0.17264(4) 0.20780(4) 0.37990(9) 0.38502(9) 0.27223 10) 0.24493(9) 0.2991(2) 0.2993( 1) 0.3554(2) 0.4066(2) 0.4063(2) 0.4582(2) 0.4549(2) 0.3994(2) 0.3483(2) 0.3503(2) 0.3502(2) 0.2749(2) 0.2157(2) 0.2885(2) 0.3268(2) 0.2892(3) 0.2 169(3) 0.1786(2) 0.1155(2) 0.0600(2) 0.0186(2) -0.0121(2) 0.0427(2) 0.0842(2) 0.1 174(2) 0.1619(2) 0.2804(2) 0.3360( 2) 0.4000( 2) 0.3820(2) 0.3282(2) 0.2636(2) 0.1489(2) 0.1158(2) 0.0754(2) 0.02 1 x 2 ) 0.0527(2) 0.0944(2)
0.29766(3) 0.25315(5) 0.19228(5) 0.4631( 1) 0.3344( 1) 0.3852( 1) 0.45874( IO) 0.3335(2) 0.3399(2) 0.3849(2) 0.4162(2) 0.4069(2) 0.4379(2) 0.4290(3) 0.3900(3) 0.3596(2) 0.3665(2) 0.3938(2) 0.3856(2) 0.2048(2) 0.18 17(2) 0.1464(3) 0.0764(3) 0.0990(3) 0.1338(2) 0.3281(2) 0.2972(3) 0.3666(3) 0.4177(3) 0.4489(2) 0.3803(2) 0.1763(2) 0.1245(2) 0.1342(2) 0.1291(2) 0.0874(2) 0.0045(2) 0.0093(2) 0.0508(2) 0.209 l(2) 0.29 15(2) 0.309 l(2) 0.2457(2) 0.1635(2) 0.1452(2)
co c1
c2 c3 C4a c4 c5 C6 c7 C8 C8a c9 c10 c11 c12 C13 C14 C15 C16 C17 C18 C19 c20 c 21 c22 C23 C24 C25 C26 C27 C28 C29 C30 C3 1 C32 c33 c34 c35
Scheme 4 0 -
6
-
c1
c2 c3 c4 C4a
c5
C6 c7 C8 C8a c9 c10 c11 c12 C13 C14 C15 C16 C17 C18 C19 c20 c 2I c22 C23 C24 C25 C26 C27 C28 C29 C30 C3 I C32 c33 c34 c35 C36
to the positively charged nickel atom then forms the metallacycle (Scheme 4). Similar mechanisms probably apply also to the reaction of 5 with C2F4 and of 2 with acetylenes. In contrast with C02, C2H4, and C2F4, the alkynes undergo double insertion with both the y2naphthalyne and y2-benzyne complexes, especially those containing PEts. This may be driven by the dissociation of one of the PEt3 ligands and by the formation of a new aromatic ring. The insertion of DMAD into the nickelaryl bond of 7 requires more vigorous conditions than 1 . the corresponding reactions of DMAD with Ni{C&C-
Ly2'-urLy2 1
(CF2)2CF2}(PEt&l5and 2.291(4)A in Ni(C&CMe2CH22)(PMe3)2,11whereas the Ni-P distance trans to the carboxylate oxygen atom of 6 is considerably less (2.144-
I
I
(2) A; cf. 2.143(4) A in ~i(CH2CMe2C6H4COb-2)(PMe3)211), consistent with the expected low trans influence of the oxygen donor.
Me)-C(CO~Me)-2}(dcpe).~Moreover, in contrast with these reactions and with the reaction of alkynes with
Discussion (2,3-y)-Naphthalyne-nickel(O)complexes Ni(y2-C&6)L2 can be generated similarly to their benzyne analogues, and they undergo similar reactions. The insertion of C02 into the nickel-naphthalyne bond of 5 can be regarded as a nucleophilic attack by coordinated naphthalyne on the electrophilic carbon atom of CO2; addition of the negatively charged oxygen atom of C02
Ni(CcH&Me2CH2-2)(PMe& leading to 1,Bdihydronaphthalenes,ll this insertion is not accompanied by reductive elimination leading to an organic product. It seems likely that reductive elimination occurs more easily in complexes containing monodentate ligands such as PMe3 or PEt3. For example, the rates of reductive elimination of ethane from cis-PdMe2Lz decrease in the order PPh3 > PMePh2 > dppe, which can be correlated
(C02Me)=C(C02Me)-2}(dcpe) or Ni{4,5-F2C6H2C(CO2-
-
I
-
Organometallics,Vol. 14,No. 4, 1995 2097
(2,3-7)-Naphthalyne-Nickel(O) Complexes
Table 4. Selected Bond Lengths (A) and Interbond Angles
Table 3. Atomic Coordinates for
(de@ for Ni(3-CtoH6CO0-2)(dcpe)(6) atom Ni I PI P2 FI F2 F3 F4 01 02 03 04
c1
c2 c3 c4 C4a c5 C6 c7 C8 C8a c9 c10 c11 c12 C13 C14 C15 C16 C17 C18 C19 C20" C20'b c 2 1" C21'h C22" C22'b C23 C24 C25 C26 C27 C28 C29 C30 C3 1 C32 c33 c34 c35 C36 c37 C38 c39 C40 C4 1 C42
v
X
-0.35724(6) -0.2423( 1) -0.1240( 1) -0.749 l(2) -0.8138(2) -0.5619(2) -0.6078(2) -0.5727(4) -0.6026(3) -0.3153(3) -0.5281(3) -0.5179(4) -0.5609(4) -0.6551(4) -7.033(4) -0.661 l(4) -0.71 18(5) -0.6665(5) -0.5708(5) -0.5203(4) -0.5650(4) -0.6942(4) -0.5588(4) -0.5158(4) -0.4447(4) -0.5638(4) -0.6452(5) -0.4208(4) -0.5202(5) -0.0389(4) 0.0096(4) -0.2588(4) -0.13 19(5) -0.35 l(3) -0.1707(7) -0.326(3) -0.2032(8) -0.354(4) -0.3248(8) -0.2923(5) -0.2927(4) -0.1968(5) -0.24 IO( 5 ) -0.2349(5) -0.3369(5) -0.2922(4) -0.0902(4) -0.1290(4) -0.1292(5) 0.0229(5) 0.0692(5) 0.0663(4) -0.059 I(4) -0.1529(4) -0.1 102(5) 0.0568(5) 0.1518(4) 0.1095(4)
-0.13854(5) -0.1 1625(8) -0.07326(8) -0.24 13(2) -0.3 194(2) -0.2338(2) -0.0897(2) -0.2197(2) -0.41 12(2) -0.0234(2) -0.0153(2) -0.4907(3) -0.3925(3) -0.3967(3) -0.4989(3) -0.60 18(3) -0.7 104(3) -0.8055(3) -0.8000(3) -0.6984(3) -0.5968(3) -0.2869(3) -0.1874(3) -0.2832(3) -0.1714( 3) -0.2988(3) -0.4287(4) -0.0653(3) 0.0838(3) -0.04 lO(3) -0.0834(3) -0.2645(3) -0.27 14(4) -0.300(2) -0.3956(4) -0.414(2) -0.4924(4) -0.5 13(2) -0.4889(4) -0.3641(3) -0.0249(3) -0.0038(3) 0.0763(3) 0.1952(3) 0.1740(3) 0.0957(3) -0.1598(3) -0.2935(3) -0.3686(3) -0.3237(4) -0.1900(4) -0.1134(3) 0.0874(3) 0.1594(3) 0.2853(3) 0.3540(3) 0.2826(3) 0.1575(3)
?:
-0.25815(3) -0.35093(4) -0.20327(4) -0.23308( IO) -0.33536( IO) -0.37438(9) -0.3149( 1) -0.0532( 1) -0.0757( 1) -0.0842( 1) -0.1378( I ) -0.198 l(2) -0.2089(2) -0.2690(2) -0.3132(2) -0.30 I8(2) -0.3463(2) -0.3328(2) -0.2758(2) -0.23 18(2) -0.2433(2) -0.2855(2) -0.3074(2) -0.1590(2) -0.1759(2) -0.0912(2) -0.0093(2) -0.1266(2) -0.0895(2) -0.3282(2) -0.2630(2) -0.3965(2) -0.4348(2) -0.45% 1) -0.4744(3) -0.493( 1) -0.4274(4) -O.M8( I ) -0.3876(3) -0.3495(2) -0.4 140(2) -0.47 19(2) -0.5201(2) -0.4842(2) -0.4289( 2) -0.3796(2) -0.1350(2) -0.1609(2) -0.1018(2) -0.0600( 2) -0.0368(2) -0.0950(2) -0.1674(2) -0.1978(2) -0.1596(2) -0.1577(2) -0.1297(2) -0.1685(2)
Nil-PI Ni 1-02 PI-c10 PI -c24 P2-CI2 OI-C9 CI-C2 C2-C3 c3-c9 C4a-C5 C5-C6 C7-C8 CIO-C11 C12-CI7 C14-CI5 C16-CI7 C18-C23 c20-c21 C22-C23 C24-C29 C26-C27 C28-C29 C30-C35 C32-C33 c34-c35 PI -Ni 1-P2 PI -Ni-C2 P2-Nil-C2 Nil-PI-CIO Nil -PI-C30 c 10-P1 -c30 Nil-P2-C11 Ni 1-P2 -C 18 Cll-P2-C18 Nil -02-C9 Nil-C2-C1 c 1 -c2-c3 c2-c3-c9 C4-C4a-C5 C5-C4a-C8a C4a-C5-C6 C6-C7-C8 CI-CSa-C4a C5a-C8a-C8 01-c9-c3
Bond Lengths 2.144(2) Nil-P2 1.900(3) Ni 1-C2 1.844(5) P2-Cll 1.842(5) PI -C30 1.832(5) P2-CI8 1.235(5) 02-C9 1.383(6) C 1-C8a 1.419(6) c3-c4 1.492(6) C4-C4a 1.423(6) C4a-C8a 1.352(7) C6-C7 1.372(7) C8-C8a 1.537(6) C12-CI3 1.532(7) C13-CI4 1.512(9) C15-Cl6 1.542(8) C18-CI9 1.502(7) C19-C20 1.489(9) c21-c22 1.547(8) C24-C25 1.520(6) C25-C26 1.520(8) C27-C28 1.54 l(7) C30-C3 1 I .544(7) C3 1-C32 1.503(8) c33-c34 1.549(8) Bond Angles 88.33(6) PI-Nil-02 96.3(1) P2-Nil-02 171.7(1) 02-NiI-C2 108.5(2) Nil-PI -C24 118.0(2) c10-PI -c24 106.2(2) C24-PI-C30 108.0(2) Nil-P2-C12 122.2(2) c 11-P2-C 12 103.9(2) C12-P2-C18 I15.5(3) C2-CI-CSa 135.3(4) Nil-C2-C3 115.1(4) c2-c3-c4 114.9(4) c4-c3 -c9 122.8(5) C4-C4a-C8a 119.6(5) C3-C4-C4a 120.8(5) C5-C6-C7 120.1(5) C7-C8-C8a 119.5(5) Cl-C8a-C8 118.1(5) 01-C9-02 122.5(5) 02-C9-C3
2.224(2) 1.936(4) 1.840(5) 1.858(5) 1.839(5) 1.307(5) 1.433(6) 1.358(6) 1.414(6) I .408(6) 1.410(8) 1.409(6) 1.528(7) 1.527(7) 1.487(9) 1.530(7) 1.535(8) 1.500(9) 1.530(7) 1.527(7) 1.5 18(8) 1.526(6) 1.530(7) 1.511(8)
175.4(1) 89.6(1) 86.3(2) 1 11.8(2) 105.7(2) 105.9(2) 109.8(2) 107.7(2) 104.4(2) 122.8(4) 109.4(3) 124.0(5) 121.0(4) I17.6(5) I20.9(4) 120.I(5) 121.3(5) 122.4(5) 123.5(5) 114.0(4)
General Procedures. All experiments were performed under a n inert atmosphere using standard Schlenk techniques,18and all solvents were dried and degassed prior to use. All reactions with benzyne complexes were carried out under argon. NMR spectra were recorded on the following instru-
ments: Varian XL-2OOE ('H at 200 MHz, 13C at 50.3 MHz, 19Fat 188.1 MHz, and 31Pat 80.96 MHz), Varian Gemini-300 BB ('H at 300 MHz and 13C at 75.4 MHz), or Varian VXR-300 ('H a t 300 MHz and 13C at 75.4 MHz). The chemical shifts ( 6 ) for 'H and 13Care given in ppm relative to residual signals of the solvent, to external 85% H3P04for 31P,and to internal CFC13 for 19F. The spectra of all nuclei (except 'H and 19F) were IH-decoupled. Coupling constants (J)are given in Hz. Infrared spectra were measured in solution (KBr cells) on a Perkin-Elmer 683 instrument. Mass spectra of the complexes were obtained on a VG ZAB2-SEQ spectrometer by means of the fast-atom bombardment (FAB) technique. Solutions of the samples were prepared with dry THF (for naphthalyne complexes) or CHzClz and added to a matrix of glycerol, 3 4 trobenzyl alcohol, o-nitrophenyl octyl ether, or degassed tetraglyme (for naphthalyne complexes). Mass spectra of organic compounds were obtained by the electron impact method (EI) on a VG Micromass 7070F spectrometer. Bis(1,5-cyclooctadiene)nickel(0)was prepared by reduction of anhydrous Ni(acac)219with Et3A1 in the presence of COD and a trace of butadiene.20 2,3-Dibromonaphthalenewas prepared by the Diels-Alder reaction of furan with 4,5-dibromobenzyne
(17)Gillie, A,; Stille, J. K. J . Am. Chem. SOC.1980,102, 4933. (18)Shriver, D. F.; Drezdzon, M. A. The Manipulation of AirSensitive Compounds, 2nd ed.; Wiley: New York, 1986.
(19)Charles, R. G.;Pawlikowski, M. A. J . Phys. Chem. 1968,62, 440. (20) Schunn, R. A. Znorg. Synth. 1974, 15, 5 .
I'
''
Populations 0.844(4). Population 0.156(4).
with the ease of dissociation of a P-donor from the coordination sphere.17 Experimental Section
2098 Organometallics, Vol. 14, No. 4, 1995
Bennett et al.
Table 5. Selcted Bond Lengths (A) and Interbond Angles
v (deg) for Ni(3-CloH6CF2CF2-2)(dcpe)(7)
Ni- IPI Ni I -C2 PI-c11 PI -c23 P2-C25 FI -C9 F3-CI0 CI-C2 C2-C3 c3-c9 C4a-C5 C5-C6 C7-C8 C9-ClO Cll-C16 C13-CI4 C15-Cl6 C17-C22 C19-C20 c 2 1-c22 C25-C26 C26-C27 C28-C29 C3 I -C32 C32-C33 c34-c35
P1-Nil -P2 PI-Nil-CIO P2-Ni I -C 10 Ni 1-PI -C 11 Nil-PI -C23 c 11-PI -c23 Ni 1 -P2 -C24 Ni 1-P2-C3 1 C24-P2-C31 C2-CI -C8a Nil-C2-C3 c2-c3-c4 c4-c3-c9 C4-C4a-C5 C5-C4a-C8a C5-C6-C7 C7-CS-CSa CI-C8a-C8 F1 -C9-F2 Fl-C9-C10 F2-C9-C10 Nil -C10-F3 Ni 1 -C 10-C9 F3-CIO-C9
I
2.2058(9) 1.926(3) 1.836(3) 1.843(3) 1.864(3) 1.377(3) I .397(3) 1.4 18(4) 1.362(4) 1.412(4) 1.414(4) 1.395(5) 1.4 16(4) 1.513(4) 1.534(5) 1 S I l(6) I .5 16(5) 1.538(5) 1.507(6) 1.538(4) 1.5334) I .5 18(5) 1.522(4) 1.532(4) I .5 17(4) 1.524(4)
Bond Angles 87.48(4) PI-Nil-C2 P2-Ni I -C2 95.0(1) C2-Nil-CIO 174.4(I ) Nil-P1 -Cl7 117.0(1) Cll-Pl-Cl7 107.1(1) C17-PI-C23 105.6(2) Nil-P2-C25 107.6(1) C24-P2-C25 117.2(1) C25-P2-C31 105.6(1) Ni 1-C2-C 1 123.8(3) C1 -C2-C3 113.7(2) c2-c3-c9 I24.4(3) C3-C4-C4a 124.2(3) C4-C4a-C8a 123.4(4) C4a- C5 -C6 118.9(4) C6-C7-C8 120.4(4) Cl -C8a-C4a 121.3(4) C4a-CSa-CS 122.33) FI -C9-C3 103.8(2) F2-C9-C3 113.3(3) C3-C9-C10 107.0(3) Ni 1-CIO-F4 120.7(2) F3 -C 10-F4 I07.0( 2) F4-CIO-C9 106.4(3)
177.43IO) 94.95( IO) 82.5(1) I14.8( 1) 105.2(1) 106.4(I ) I 1331) 105.4(I ) 106.7(1) 132.2(2) I14.1(3) 1 I1.3(3) 120.5(3) 117.6(3) 121.2(4) 120.2(4) 11933) 118.0(3) 113.2(3) 1 1 I .9(3) 107.5(3) I13.5(2) 102.5(2) 105.7(3)
~~
0
1
Ni{~ - C ( C O ~ M ~ ) = C ( C O ~ M ~ ) C & & F ~ C F(10) ~-~)(~C~~)
Bond Leneths Ni I -P2 2.203(1) Nil-CIO 1.944(3) PI-Cl7 1.862(3) P2-C24 1.833(3) P2-C31 1.839(3) F2-C9 1.383(3) F4-CI0 1.409(3) CI-C8a I .386(4) c3-c4 1.429(4) C4-C4a 1.498(4) C4a-C8a 1.421(4) C6-C7 1.352(5) C8-C8a 1.368(5) C11-CI2 1.527(4) C12-Cl3 1.524(4) C14-C15 1.502(6) C17-CI8 1.53l(5) C18-CI9 1.525(4) c20-c21 1.506(5) C23-C24 1.533(5) C25-C30 1.533(4) C27-C28 1.527(4) C29-C30 1.516(5) C31-C36 1.528(4) c33-c34 1.528(4) C35-C36 1.51O( 5 ) ~
Table 6. Selected Bond Lengths (A) and Interbond Angles (deg) for
-
generated by the action of n-BuLi on 1,2,4,54etrabromobenzene; the resulting epoxide was deoxygenated by treatment with Zn/TiC14.21 Microanalyses were done in-house. Preparation of NiBr(3-Br-2-CloHd(PEt~)~ (1). A suspension of Ni(COD)2 (2.63 g, 9.6 mmol) in n-hexane (60 mL) was treated successively with PEt3 (3.6 mL, 24.2 mmol) and solid 2,3-dibromonaphthalene (3.9 g, 13.6 mmol). The mixture was stirred for 35 min a t room temperature, for 1 h under reflux, and again for 16 h at room temperature. The solution was filtered through Celite, and the residue was washed with toluene (4 x 5 mL). The solution was evaporated to dryness, and the brown oil was crystallized from MeOWtoluene (40 mL/ 15 mL) to yield 1 as a brown solid (4.87 g, 83%). IR (CH2C12): 3045 (w), 2975 (s), 2945 (m), 2920 (m), 2890 (m), 1578 (w), 1560 (w), 1487 (m),1460 (m), 1418 (m), 1402 (m), 1195 (w), 1137 (w), 1105 (w), 1065 (m), 1040 (vs), 945 (m), 880 (s) cm-'. 'H NMR (200 MHz, CsD6): B 0.99 (quint, 18H, 35= 7.5, CH3), (21)( a ) Hart, H.; Lai, C.; Chukuemeka, G.; Shamouilian, S. Tetrahedron 1987, 43, 5203. (b) Hart, H.; Bashir-Hashemi, A,; Luo, J.; Meador, M. A. Tetrahedron 1986,42,1641. (c) Akula, M. R. Org. Prep. Proced. Int. 1990, 22, 102.
Nil-P1 Nil -C10 Pl-CI7 PI-C25 P2-c3 I FI-C9 F3-CIO 01-C13 02-Cl4 04-Cl5 c 1-c2 C2-C3 c3-c4 C4-C4a C4a-C8a C6-C7 C8-C8a Cll-c12 C12-CI5 C I9-C20 c20-c21 C22-C23 C25-C26 C26-C27 C28-C29 C3 I -C32 C32-C33 c34-c35 C37-C38 C38-C39 C40-C4 I PI -Ni 1-P2 Pl-Nil-Cl2 P2-Ni I -C 12 Ni I -PI -C17 Nil-Pl-C25 c17-PI -c25 Ni 1-P2-C 18 NiI-P2-C37 C 18-P2-C37 C13-02-C14 C2-Cl-CSa c1-c2-CI I c2-c3-c4 c4-c3-c9 C4-C4a-C5 C5-C4a-C8a C5-C6-C7 C7-C8-C8a Cl-C8a-C8 FI-C9-F2 FI-C9-C10 F2-C9-CIO Nil-CIO-F3 Nil-CIO-C9 F3-CIO-C9 C2-Cll-C12 C12-Cll-CI3 Nil -C 12-C15 0 1 -C13-02 02-C13-C11 0 3 -C 15-C 12 PI -C17-C 18
Bond Lengths 2.23 I( 1) Ni I -P2 1.955(4) Ni 1-C 12 1.833(4) PI-c19 1.850(3) P2-CI8 1.837(3) P2-C37 1.367(4) F2-C9 I .419(4) F4-CIO 1.194(4) 02-C13 1.441(4) 03-C15 1.334(4) 04-C16 1.368(4) C 1-CSa I .432(4) c2-CI 1 I .372(4) c3-c9 1.418(4) C4a-C5 1.4I4(5) C5-C6 1.388(6) C7-C8 1.416(4) C9-ClO 1.350(4) Cll-C13 I .488(4) C17-CI8 C19-C24 1.497(5) 1.534(6) c21-c22 1.462(7) C23-C24 1.523(4) C25-C30 1.523(5) C27-C28 I .5 14(5) C29-C30 1.537(4) C3 I -C36 1.533(4) c33-c34 1.517(5) C35-C36 1.530(4) C37-C42 1.535(5) C39-C40 1.514(6) C41 -C42 Bond Angles 85.84(4) P 1-Ni 1-C 10 173.24(10) P2-Ni 1-C 10 90.88(10) C10-Ni1-CI2 Nil-PI -C19 109.0(1) 119.4(1) C17-Pl-CI9 103.8(2) C19-PI-C25 108. I ( 1) Ni 1-P2-C3 1 114.5(1) C18-P2-C3 1 105.8(2) C31 -P2-C37 115.5(3) C I5 -04-C 16 122.7(3) CI-C2-C3 121.9(3) c3-c2-c11 119.9(3) c2-c3-c9 120.0(3) C3-C4-C4a 123.2(4) C4-C4a-C8a 118.5(3) C4a-C5-C6 12 I . l(4) C6-C7-C8 120.7(4) CI-C8a-C4a C4a-C8a-C8 122.4i4j F1 -C9-C3 103.5(3) I10.1(3) F2-C9-C3 I09.6( 3) C3-C9-C10 Nil -C10-F4 I12.7(2) F3 -C IO-F4 121.9(2) F4-C 10-C9 100.4(3) 12 I .7(3) C2-Cll-Cl3 Ni 1 -C12-C1 I 119.9(3) I16.4(2) Cll-C12-C15 OI-Cl3-Cll 120.9(3) 0 3 -C 15-04 I14.3(3) 04-Cl5-Cl2 125.9(3) P2-CI8-Cl7 109.4(2)
2.243( 1) I .924(3) 1.869(3) 1.839(3) 1.860(3) 1.382(4) 1.382(3) 1.320(4) I .203(4) 1.447(4) 1.416(4) I .499(4) 1.503(4) I .430(4) 1.355(5) 1.364(5) 1.546(4) 1.484(4) 1.527(4) 1.530(4) 1.505(7) 1.535(5) 1.534(4) 1.513(5) I .525(4) 1.530(4) 1.51 x 5 ) 1.534(5) 1.537(4) 1.513(5) 1.532(5) 93. I( 1) 177.1(1) 90.4(1) I12.3( 1) 104.8(2) 106.4(2) 116.2(1) 105.6(2) 105.9(2) 115.1(3) 118.4(3) I19.6(3) 120.0(3) 12 1.9(3) 118.3(3) 120.3(4) 12034) 118.8(3) 118.8(3) I 1 1.3(3) 109.7(3) 112.3(3) I 1 1.7(2) 102.7(2) 105.4(3) I18.2(3) 124.4(2) 119.0(3) 124.8(3) 122.9(3) I I1.0(3) 107.8(2)
1.22-1.57 (m, 12H, CH2), 7.05 (t, l H , 35= 7, H6 or H7), 7.18 7.39 (d, l H , 35= 8, H5 or He), 7.46 (d, (t, l H , 3 5 = 7, H7 or H6), l H , 35= 8, HEor H5),7.70 (9, l H , H' or H4),7.77 (s, l H , H4 or H'). 13C(1H}NMR (75.4 MHz, CsDs): d 8.38 (CH31, 14.88 (t, J c p = 12.6, CHz), 124.21 (CH), 125.82 (CHI, 125.93 (CHI, 127.02 (CH), 127.18 (CHI, 131.47 (C4aor Cea),132.20 (CRaor C4a),133.07 (br s, C3), 137.42 (t, JCP= 4.4, C'-H), 157.99 (t, Jcp = 34, C2). 31P{'H} NMR (80.96 MHz, CsDs): d 9.8 (SI. FAB-
(2,3-r,+Naphthalyne-Nickel(O) Complexes MS (tetraglyme, C2zH36BrzNiPz): mlz 501 (18, 2-Br-CloHsNi(PEt&), 325 (951, 323 (100, 2-Br-3-PEt~CloHs),295 (271, 294 (37),293 (47, Ni(PEt3)z);the molecular ion a t mlz 578 was not observed. Anal. Calcd for C~zH36Br2NiP2:C, 45.48; H, 6.25; P, 10.66; Br, 27.51. Found: C, 45.12; H, 6.37; P, 10.41; Br, 27.16. Preparation of Ni((2,3-tl)-CloHs)(PEts(2). )z A 1% sodium amalgam (494 mg of Na, 3.6 mL of Hg) suspended in THF (30 mL)was cooled to 0 "C and treated with 1 (646 mg, 1.11mmol). The mixture was stirred a t room temperature for 3.5 h and decanted into a flask kept a t -30 "C. The solvent was evaporated a t 0 "C, the residue was extracted with hexane (6 x 10 mL), and the extract was filtered through Celite into a flask kept at -78 "C. The volume of solvent was reduced to about half. The complex was crystallized at -78 "C to yield 2 as a yellow oily solid (464 mg, 90%). IR (hexane): 3030 (w), 1585 (s, C=C), 1505 (m), 1250 (m), 1192 (m), 1178 (m), 1030 (s), 838 (s), 760 (vs), 725 (vs) cm-'. 'H NMR (200 MHz, C&): 6 0.85-1.05 ([&BzX] m, 18H, J = 7.5, CH3), 1.45-1.65 ([A~BzX] m, 12H, J = 7.5, CH2), 7.37-7.44 ([AA'BB'] m, 2H, H6b7),8.04 (s, 2H, H1x4),8.05-8.15 ([AA'BB'] m, 2H, H5J9 I3C{'H} NMR (75.4 MHz, CsD6): 6 9.00 (CH31, 19.94 (d, JCP = 20.7, CH2), 118.14 (CHI, 123.64 (CHI, 128.17 (CH), 137.72 (C4=9'=),142.52 (C233).31P{1H}NMR (80.96 MHz, C&,): 6 27.0 (br s). FAB-MS (tetraglyme, C22H36NiP~):mlz 420 (100, M), 393 (431, 391 (68, M - Et), 296 (46), 294 (92, Ni(PEtd2). Preparation of NiBr(3-Br-2-CloHe)(PPh3)~ (3). A suspension of Zn (0.43 g, 6.5 mmol) in THF (5 mL) that had been activated by ultrasound for 40 min a t room temperature was treated successively with a solution of 2,3-dibromonaphthalene (1.6 g, 5.6 mmol) in THF (7 mL), NiBr2(PPh& (3.5 g, 4.7 mmol), AIBN (56 mg), and THF (10 mL). The green solution was stirred for 2.5 h a t 25 "C to give a brown suspension. The solvent was removed by evaporation, the residue was extracted with CH2C12, and the solution was filtered through Celite. The volume of filtrate was reduced to 20 mL under reduced pressure. On addition of hexane (20 mL) and cooling to -78 "C, complex 3 crystallized. The yield was 3.58 g (88%). 'H NMR (200 MHz, CDZC12): 6 7.00-7.80 (m, 36H). 31P{1H} NMR (80.96 MHz, CD2C12): 6 22.2 (SI. Preparation of NiBr(3-Br-2-CloHe)(dcpe) (4). A solution containing 3 (3.58 g, 4.1 mmol) and dcpe (1.9 g, 4.51 mmol) in toluene (70 mL) was stirred for 3 h a t 60 "C. The solution was filtered through Celite, and the solid formed during the reaction was extracted with CHZC12. The solvent was removed by evaporation, and the compound was purified by column chromatography (silica gel, CH2C12). The yield of 4 was 2 g (64%). 'H NMR (200 MHz, CD2C12): 6 1.15-2.60 (m, 48H, CH2 and CsH11), 7.14-7.39 (m, 3H, Harem), 7.49-7.63 (m, 2H, NMR (75.4 MHz, CD2C12): 6 Harom), 7.74 (br s, l H , Harem). 19.30 (dd, J c p = 20.8, J c p = 10.9, CHp), 23.92 (t, J c p = 20.9, CH2),25.94-28.13 (m, CHz), 28.50, 29.28, 29.49, 30.32, 32.38 (CH2), 32.60 (d, J c p = 241, 33.71 (d, J c p = 20.91, 35.52 (d, J c p = 19.8), 36.99 (d, J c p = 24.1, CH of CsHii), 123.94, 125.21, 126.43, 126.84, 127.83 (CH), 131.87, 132.41, 135.03 (C), 136.72 (CH), 159.35 (dd, J c p = 86.0, J c p = 33.9, C2). 31P{1H}NMR (80.96 MHz, CDzC12): 6 65.3, 68.0 ([AB] q, '5 = 28.2). FABMS (3-nitrobenzyl alcohol, C36H54Br2NiP~):m/z 766 (23, MI, 687 (100 M - Br). Anal. Calcd for C36H54Br2NiP~:C, 56.35; H, 7.09; P, 8.07. Found: C, 57.07; H, 7.89; P, 7.80. Preparation of Ni((2,3-;rl)-CloHe)(dcpe) (5). A 1% sodium amalgam (572 mg of Na, 4 mL of Hg) suspended in THF (60 mL) was cooled to 0 "C and treated with 4 (2.86 g, 3.76 mmol). The mixture was stirred for 3 h a t 25 "C. At this stage, 31P NMR spectroscopy showed that 5 had been formed quantitatively. The solution was decanted, the solvent was removed by evaporation, and the residue was extracted with toluene. The extract was filtered through Celite and pumped to dryness under a vacuum. The brown oil was washed with hexane and dissolved in THF, and the product was precipitated as a yellowbeige powder by adding hexane at -20 "C. The yield of 5 was 1 g (44%). 'H NMR (300 MHz, CsDs): 6 0.80-2.25 (m, 48H,
Organometallics, Vol. 14, No. 4, 1995 2099 CH2 and CsHll), 7.37-7.40 ([AA'BB'] m, 2H, H6s7),8.11-8.14 13C{1H}NMR (75.4 ([AA'BB'] m, 2H, H54, 8.42 (s, 2H, MHz, CsD6): 6 22.31 (t, J c p = 19, CHz), 26.25 (t, J c p = 19, CHd, 26.41, 26.92, 27.53, 29.67, 30.01 (CHz of CsHii), 35.16 (t,JCP = 10.5, CH Of C ~ H ~ 121.62, I), 123.58 (CH), 138.51 (C4's8'), 144.4-144.9 (m, C23)(one naphthalenic CH signal hidden by CsDs). 31P{1H}NMR (80.96 MHz, CsDs): 6 77.3 (SI. FAB-MS (tetraglyme, C36H54NiP2): mlz 607 (M 1). Reaction of 5 with COz. A sample of the crude naphthalyne complex 5 (prepared by 1%N a g reduction of 4 (0.575 g, 0.75 mmol) in THF) was exposed a t -78 "C to 1atm of COz.
+
The yellow monoinsertion complex Ni(3-C10HsC00-2)(dcpe)(6) was isolated (123 mg, 25% based on 4) and purified by crystallization from CHzC12. IR (CH2C12): 2935 (s), 2870 (m), 1632 (s), 1615 (m), 1450 (w), 1325 (m), 1285 (w)cm-'. 'H NMR (200 MHz, CDZC12): 6 1.10-2.20 (m, 48H, CH2 and C6Hll), 7.37 (quint, 2H, 3J = 7.5, H6,7),7.58 (d, l H , JHP = 6.4, IT'), 7.71 (d, l H , 3J = 7.5, H50r8),7.81 (d, l H , J = 7.5, HSor5),7.87 (s, l H , H4). 13C NMR (75.4 MHz, CD2C12): 6 26.31 (t, Jcp = 11.0, CHd, 27.08-28.99 (m, CH2), 29.19, 29.92 (CH2), 32.06 (d, J c p = 3.3, CH2 Of C6Hii), 34.01 (d, J c p = 16.5, CH Of CsHii), 36.58 (d, J c p = 22.0, CH of CsHii), 124.67, 126.12, 126.24, 127.50, 129.03 (CHI, 131.74 (C4a),135.29 (dd, J c p = 6.6, J c p = 3.2, C'-H), 135.63 (d, Jcp = 7.5, C8'), 142.06 (C3), 150.24 (dd, J c p = 80.1, J c p = 27.5, C2);the CO2 carbon was not visible. 31P(1H}NMR (80.96 MHz, CD2C12): 6 68.7, 76.1 ([AB] q, ' J p p = 25.0). FAB-MS (3-nitrobenzyl alcohol, C37H54Ni02P2): mlz 651 (100, M 1). Anal. Calcd for C37H54Ni02P2: C, 68.22; H, 8.35; P, 9.51. Found: C, 67.74; H, 8.69; P, 8.51. Reaction of 5 with CzF4. A solution of 5 (prepared by reduction of 4 (0.85 g, 1.11mmol) with 1% N a g ) in THF (20 mL) was placed under 1 atm of C2F4 at -60 "C and stirred for 16 h while the solution was warmed to room temperature. The solution was filtered through silica gel, the solvent was removed by evaporation, and the residual solid was washed
+
-
with hexane to give N ~ ( ~ - C I O H ~ C F ~ C (7; F ~ 590 - ~ )mg, (~C~~) 75% based on 4). Crystals suitable for X-ray analysis were obtained from CHZCl@tOH. 'H NMR (200 MHz, CDzC12): 6 1.00-2.30 (m, 48H, CH2 and C6H11), 7.32-7.49 (m, 2H, H6s7), 7.72 (d, l H , 3J = 7.7, H50r8),7.78-7.92 (m, 3H, HSor5, NMR (75.4 MHz, CD2C12): 6 19.98 (dd, J c p = 21.9, J c p = 16.4, CHz), 20.72 (dd,J c p = 2 3 . O , J c p = 16.4, CHz), 26.42,26.58, 27.53, 27.65, 27.82, 27.92, 28.00, 28.11 (CH21, 29.53 (d, J c p = 3.31, 29.65 (d, J c p = 3.31, 30.72 (d, Jcp = 4.4), 31.50 (d, Jcp = 5.4, CH2 of CsHii), 35.67 (d, J c p = 25.3, CH of CsHii), 35.91 (d, Jcp = 26.3, CH of CsHii), 121.23, 124.67, 125.98, 127.62, 128.44 (CH), 131.76, 133.84 (C4a38a), 137.74 (d, J c p = 6.6, C'H), 142.73 (t, JCF = 20.4, C3), 156.6-157.6 (m, C2);CF2 not visible. I9FNMR (188.1 MHz, CD2C12): 6 -106.06 (br s, 2F), = 31.4, JFP = 19.8, JFF = 10.7). 31P{1H} -96.28 (ddt, 2F, JFP NMR (80.96 MHz, CDzClZ): 6 65.1 (dtt, J p p = 14.5, 3 J ~ = p 31.3, 4JFp = 4.41, 69.4 (dt, J p p = 14.5, 3 J F p = 19.7). FAB-MS (3nitrophenyl octyl ether, C38H54F4NiP2): mlz 706 (15, MI, 687 (14, M - F), 499 (871, 480 (100). Anal. Calcd for C38H54F4NiPz: C, 64.51; H, 7.69; P, 8.76. Found: C, 63.63; H, 7.90; P, 8.43. Reaction of 2 with DC1. A few drops of 35% DCL'D20 were added to a solution of 2 (50 mg) in CsDs in a 5 mm NMR tube. After 5 min a t room temperature, the reaction was complete (31PNMR) to quantitatively form NiClz(PEt& (6 11.6)and 2,3dideuterionaphthalene. The solution was dissolved in ether (10 mL), washed with water ( 3 x 10 mL), and dried over MgS04. The solvent was removed, and 2,3-Dz-CloHs was purified by sublimation. 'H NMR (200 MHz, CDzClz): 6 7.447.50 (AA'BB', 2H, H6s7),7.81-7.88 (AA'BB', 2H, H5,9,7.84 (s, 2H, 13C{1H}NMR (50.3 MHz, CDzClZ): 6 126.15 (C6-H and C7-H), 128.01 (CI-H and C4-H) (isotopic shift), 128.13 (C5-H and C8-H), 133.80 (C4a,8a); the resonance due to CZ3 was not located. GC-MS (CloHsDz): mlz 130 (100, MI, 129 (30), 128 (10);retention time 6 min (column BPI 12.5 m, initial temperature 50 "C, final temperature 180 "C, AT = 10 "C1
2100 Organometallics, Vol. 14,No. 4, 1995 Table 7.
chem formula fw cryst syst unit cell dimens a
(A)
h (A) c (A)
Bennett et al.
Crystal and Structure Refinement Data for Compounds 6, 7, and 10
C~~HS~N~O:P?CH?CI? 736.4 1 monoclinic
(a) Crystal Data ClxHsJF4NiP? 707.49 monoclinic
14.714(2) I7.100(1) 15.990(2)
11.139(2) 19.557(2) 16.809(2)
110.244(9)
92.927(9)
3774.8(7) P21ln(No. 14) 1.296 4 I568 yellow, block 0.08 x 0.11 x 0.21 30.80 (Cu K a )
3657.1(6) P2llc (NO. 14) 1.285 4 1504 yellow, block 0.28 x 0.10 x 0.06 19.65 (Cu K a )
a (deg)
P (deg)
y (de@ V(deg) (A') space group D, (g cm-3)
Z color, habit cryst dimens p (cm-')
CJJH~OFJN~O~P? 849.60 triclinic 9.4 1 x 3 ) I I .759(2) 20.2 I8(3) 93.94( 1) 94.77(2) 108.90(2) 2099.3(8) PI (No. 2) I .344 2 900 pale yellow, plate 0.24 x 0.10 x 0.03 18.80 (Cu K a )
(b) Data Collection and Processing
diffractometer X-radiation scan mode w-scan width 28 limits (deg) data collected (hkl) no. of reflns total unique (R,,,,/%) obsd abs cor (transmission factors) secondary extinction cor coeff structure s o h refinement no. of params weighting scheme R(obsd data) (96) R,(obsd data) ('7%)
Rigaku AFC 6R Cu K a (graphite monochromated) 0-28 1.42 0.30 tan 8 120.0 (-17,0,0) to(17.19.18)
Rigaku AFC 6R Cu K a (graphite monochromated) w-2e 1.10 0.30 tan 8 120.3 (0.0,-19) to (12,22.19)
Rigaku AFC 6R Cu K a (graphite monochromated) 0-28 1.20 0.30 tan e 120.3 (-11,-13,-23) to(0,13,23)
605 8 5825 (3.75) 2997 ( I > 3a(f)) azimuthal scans (0.43- 1.00) [1.5(4)] x IO-*
5833 5621 (2.0) 3872 ( I > 30(f)) azimuthal scans (0.90- 1.00) [3(2)] x
6612 6231 (1.7) 4432 ( I > 3a(f)) azimuthal scans (0.88- 1.00)
+
+
(c) Structure Analysis and Refinement" direct methods (SAP19 l?? Patterson methods DIRDIF92?') (PATTY, DIRDIF92)?' full-matrix least squares full-matrix least squares 407 407 4F,?I[a?(FO2) (O.OOlF,?)?] 4F,21[a?(F,?) (0.005F,?)2] 3.5 4.1 2.9 2.8
+
+
+
Patterson methods (PATTY, DIRDIF92)?' full-matrix least squares 509 4F0?/[0?(F,,?) (0.004F0?)?] 3.6 3.0
+
(' All calculations were performed using teXsan24with neutral atom scattering factors from Cromer and Waber.? Afand Af' values from ref 26, and mass attenuation coefficients from ref 27. Anomalous dispersion effects were included in Fcalc.2x min, injector temperature 200 "C); for comparison, the retention time of naphthalene is 6 min. Reaction of 2 with Dimethyl Acetylenedicarboxylate (DMAD). Addition of DMAD (0.1 mL, 0.74 mmol) in THF (2 mL) to a solution of 2 (260 mg, 0.62 mmol) in THF (20 mL) a t -50 "C gave a black solution. The mixture was stirred for 3 h a t -30 "C, and the solvent was evaporated to give a red oil which showed a peak a t 6 26.6 in the 31PNMR spectrum, probably due to Ni(q2-DMAD)(PEt3)2. The organic componds were separated by column chromatography (silica gel, ether) to give tetramethyl anthracene-1,2,3,4-tetracarboxylate (8;40 mg, 16%) together with a trace of hexamethyl benzenehexa(8): IR (CHC13)2960 (w), carboxylate. 1,2,3,4-(CO~Me)~-c14Hs 1740 (s), 1445 (m), 1365 (w), 1305 (w)cm-'; 'H NMR (200 MHz, CDC13) 6 3.92 (s, 6H, OCH3), 4.07 (s, 6H, OCHs), 7.55-7.63 (AA'BB', 2H, H73), 7.97-8.05 (AA'BB', 2H, H6,'), 8.62 (s, 2H, H5
