Organometallics 1993,12, 4151-4160
4151
A New Example of a Palladium-Assisted Aryl Rearrangement. Synthesis and Reactivity of (2,3,4-Trimethoxy-6-X-phenyl) palladium [X = CHO, CH=N(n-CloHzl), CH=NC6H4( NH2) -2, C(0)Me] and (3,4,5-Trimethoxy-2-X-phenyl)palladium [X = CHO, CH--NC&( NH2) -21 Complexes. Crystal and Molecular Structure of
[P~(K~-C~H(CH=NC~H~(NH~)-~)-~-(OM~)~-~,~,~ [P~(K~-C CH=NC6H4(NH2)-2)-2-(OMe)3-3,4,5) ~H (PPh3)]CF&03,
r,
and [Pd(K -C6H(C(O)Me)-6-(OMe)3-2,3,4)(2,9-dimethyl-l,10phenanthroline)]CF3S03 Josh Vicente, JosB-Antonio Abad,’ and Juan Gil-Rubio Grupo de Quimica Organomet&lica,Departamento de Quimica Inorg&nica, Facultad de Quimica, Universidad de Murcia, Apartado 4021, Murcia, 30071 Spain
Peter G. Jones* and Eberhard Bembenek Institut fur Anorganische und Analytische Chemie, Technische Universitat Braunschweig, Postfach 3329, 38023 Braunschweig, Germany Received May 4, 1993”
The reaction of [Pd(R)Cl(bpy)l [R = CsH(CHO)-6-(OMe)3-2,3,4; bpy = 2,2’-bipyridinel (1) with AgC104 results in the O-coordination of the formyl group and the isomerization of the aryl ring to give [Pd(~~-R’)(bpy)lC104 (2) [R’ = CsH(CHO)-2-(0Me)3-3,4,51. [HgR21 or [Hg(R)Cl] reacts with n-decylamine or o-phenylenediamine to give respectively [Hg(RN)2] (3) [RN = CsHICH=N(n-CloH2l))-6-(OMe)3-2,3,41 or [Hg(RNN)Cll (4) [RNN = C,#{CH=N(C&(NH2)(5) and with 4, 2)-6-(OMe)3-2,3,4]. [PdC12(MeCN)21reacts with 3 to give [Pd(~~-RN)(p-C1)12 PPh3, and K(CF3S03) giving [P~(K~-RNN)(PP~~)ICF~SO~ (6). The reaction of 5 with AgC104 and, after removal of AgC1, with 2,2’-bipyridine (bpy) gives [Pd(K2-RN)(bpy)]C104 (7). [PdC ~[R’NN ] = CsH(K~-R’) (p-Cl)]p (8) reacts with o-phenylenediamine to give [ P ~ ( K ~ - R ’ N N )(9) (CH=NCsH4(NH2)-2)-2-(OMe)3-3,4,51 which reacts with PPh3 in the presence of K(CFS03), yielding [ P ~ ( K ~ - R ’ N N ) ( P P ~ ~ )(6’). ~ C F[Hg(RMe)Cll(lO) ~SO~ [RMe = CsH(C(O)Me)-6-(OMe)3with Hg(MeC02)~ 2,3,4] can be obtained by direct mercuriation of 3,4,5-trimethoxyacetophenone and subsequent treatment with KC1. [Hg(RMe)zl (ll),obtained by symmetrization of 10 with Me4NC1, reacts with [PdC12(MeCN)21 or aqueous [PdC1412- to give the cyclometalated [Pd(~~-RMe)(p-C1)]2 (12) which reacts with bpy or 2,9-dimethyl-l,lO-phenanthroline (dmphen), giving the neutral complexes [Pd(RMe)Cl(N-N)I [N-N = bpy (13),dmphen (14)l. 13 and 14 react with Ag(CF3S03),giving the cationic cyclometalated compounds [ P ~ ( K ~ - R M ~ ) ( N - N ) ] C F ~ SO3 [N-N = bpy (15), dmphen (16)l. The structures of 6CH2C12, 6’.Et20, and 16*CH2C12have been determined by X-ray crystallography a t -95 “C. Crystal data for 6.CHzC12: space group Pi, a = 12.452(3) A, b = 12.754(3) A, c = 13.275(3) A, CY = 111.34(2)”, p = 104.21(2)’, 7 = 95.32(2)’, V = 1846.5 A3, 2 = 2, R i n t = 0.033; R(F, >4a(F)) = 0.040. Crystal data for 6’.1.5Et&: space group P21/c, a = 11.228(6) A,b = 16.818(6) A,c = 22.650(9) A,p = 101.61(4)”, V = 4190 A3, 2 = 4, Rint = 0.033, R(F, >4a(F)) = 0.050. Crystal data for 16CH2C12: space group ml/n, a = 12.199(4)A,b = 7.801(3) A,c = 30.910(11) A,/3 = 95.80(3)’, V = 2927 AS, 2 = 4, Rht = 0.061, R(F, >4a(F)) = 0.050. The three complexes show distorted square planar geometries. Introduction
We are currently interested in illustrating the synthetic utility of organomercury derivatives in the preparation of new types of functionalized aryl complexes not easily accessible through the ((standard”methods (see Scheme 11.l For example, we have recently used this method to prepare the first 2-formylaryl complexes of palladium(I1) a Abstract published in Advance ACS Abstracts, September
15,1993.
containing the arylgroup R = CeH(CHO)-6-(OMe)3-2.3,4.2 . . . This tranimetalatik reaction-takes place in water, but extraction of the product with dichloromethane gave a palladium(I1) derivative containing the rearranged aryl (1) See for example: Vicente, J.; Chicote, M. T.;Ramlrez-de-Arellano, M. C.;Jones,P. G .J . Chem. Soc.,Dalton Trans. 1992,1839andreferences therein* (2) Vicente, J.; Abad, J. A.; Stiakaki, M. A.; Jones, P. G.J. Chem. SOC., Chem. Commun. 1991, 137. (b) Vicente, J.; Abad, J. A,; Jones, P. G. Organometallics 1992, 11, 3612.
0276-733319312312-4151$04.00/0 0 1993 American Chemical Society
4152 Organometallics, Vol. 12, No. 10, 1993
Vicente et al.
Scheme I. Some Examples of the Synthetic Utility of Organomercury Derivatives
group R’ = CeH(CHO)-2,(0Me)3-3,4,5(see Scheme I). In this paper we report investigations of the scope of this rearrangement reaction, using similar palladium complexes in which the formyl substituent is replaced by others also able to coordinate to the metal atom. The presence of three methoxy substituents in the aryl ring was decided upon because these electron releasing groups could confer special properties to the formyl group, e.g. facilitating its coordination to palladium to give cyclometalated species. In addition, this aryl moiety is present in organic molecules of pharmaceutical interest, for example the antileukemic lactones steganacin and steganangin? the antibacterial agent trimethoprim: or the cytotoxic colchicine.6 We plan to use these aryl complexes in organic synthesis, and we have already reported preliminary results concerning the synthesis of indenones and indenols obtained from these (formyltrimethoxyaryl)palladium(II) derivatives (see Scheme II).6 Ortho-manganated acetophenones have been prepared by reacting these ketones with P ~ C H Z M ~ ( C OSome )~.~ of these compounds have been used as transmetalating reagents in the synthesis of the corresponding chloromercury derivative^.^' The method was implemented on the assumption that, because direct mercuriation of acetophenone occurs at the Me group rather than at the aryl ring! all acetophenones would behave ~imilarly.7~9’ In this paper we report the synthesis of [Hg{C6H{C(O)Me)-6(OMe)3-2,3,4)ClI by direct mercuriation of the corresponding acetophenone. These arylmanganese derivatives (3) Ziegler, F. E.; Chliwner, I.; Fowler, K. W.; Kanfer, S. J.; Kuo, S. J.; Sinha, N. D. J. Am. Chem. SOC.1980,102,790. Tomioka, K.; Ishiguro, T.; Mizuguchi, H.; Komeshima, N.; Koga, K.; Tsukogoshi, S.; Tsuruo, T.; Tashiro, T.; Tanida, S.; Kishi, T.J.Med. Chem. 1991,34,54 and references therein. (4) Chan. J. H.: Roth, B. J.Med. Chem. 1991,34,550 and references therein. (5) Ringel, I.; Jaffe, D.; Alerhand, S.; Boye, 0.; Mazafar, A.; Brossi, A. J. Med. Chem. 1991,34, 3334. (6) Vicente, J.; Abad, J. A.; Gil-Rubio, J. J.Organomet. Chem. 1992, 436,
C9.
Scheme 11. Synthesis of Indenones and Indenols Obtained from (Formyltrimethoxyaryl)palladium(II) Derivatives
1/2
M
e
0
4H
w-
Me0
OM0
Ph Ph
+ Ph& + HzO -L
L = W N
have also been used, directly7’ or indirectly, through palladium(I1) complexes,”’ in organic synthesis. These latter reactions should occur via the mediation of an (7) (a) McKinney, R. J.;Kaesz, H. D. J.Am. Chem. SOC.1975,97,3065. (b) McKinney, R. J.; Firestein, G.; Kaesz, H. D. Inorg. Chem. 1975,14, 2057. (c) Knobler, C. B.; Crawford, S. S.; Kaesz, H. D. Inorg. Chem. 1975, 14,2062. (d) Huie, B. T.; Knobler, C. B.; Firestein, G.; McKinney, R. J.; Kaesz, H. D. J.Am. Chem. SOC.1977,99,7852. (e) Huie, B. T.; Knobler, C. B.; McKinney, R. J.; Kaesz, H. D. J. Am. Chem. SOC.1977,99,7862. (0 Crawford, S. S.; Kaesz, H. D. Inorg. Chem. 1977, 16, 3193. (g) McGuiggan, M. F.; Pignolet, L. H. Inorg. Chem. 1982, 21, 2523. (h) Gommans, L. H. P.; Main, L.; Nicholson, B. K. J. Chem. Soc., Chem. Commun.1987, 761. (i) Cooney, J. M.; Gommans, L. H. P.; Main, L.; Nicholson, B. K. J.Organomet. Chem. 1987,336,293. (i)Ibid. 1988,349, 197. (k) Robinson, N. P.; Main,L.; Nicholson,B. K. J.Organomet. Chem. 1988, 349, 209. (1) Liebeskind, L. S.; Gasdaska, J. R.; McCallum, J. S.; Tremont, S. J. J. Org. Chem. 1989, 54, 669. (8)0. Dimroth (1902) quoted in: Larock, R. C. Organomercury Compounds in Organic Synthesis; Springer-Verlag: Berlin, 1985; p 28.
Organometallics, Vol. 12, No. 10, 1993 4153
Palladium-Assisted Aryl Rearrangement
Chart I
Me0$MeOMe Y
H Me
M e OOMe z M e
X O
R
0
RMe
Y
H N(n-CloH2,) RN
X
Me 0 2-RMe H N(n-CloH21) 2-RN
Me0 OMe RNN
OMe x3-RNN
OMe x3-R'NN
arylpalladium complex. In this work we report the synthesis of an ortho-palladated acetophenone, which cannot be obtained by a direct metalation reaction, using the corresponding mercurial.
Experimental Section C, H, and N analyses, melting point determinations, and recording of the IR and NMR spectra were performed as described e l s e ~ h e r e . The ~ group CeH(CHO)-6-(OMe)3-2,3,4has been symbolized as R, the rearranged group CsH(CHO)-2-(OMe)3as RMe, and 3,4,5as R', the ketone CsH(C(O)Me}-6-(OMe)3-2,3,4 the Schiff bases CsH(CH=N(n-CloH21)(OMe)3-3,4,5, C6H{CH=NCsH4(NH2)-2}-6-(OMe)3-2,3,4, and C6H(CH=NCsH4(NH2)-2}-2-(OMe)3-3,4,5 as RN,RNN,andR'NN (see Chart I). When some of these ligands are bonded to palladium through two or three donor atoms we use the K notations KZ or 9, respectively, while only the abbreviation of the ligand if it is bonded through one donor atom (see Chart I). The ligands 2,2'have been bipyridine and 2,9-dimethyl-l,lO-phenanthroline symbolized as bpy and dmphen, respectively. Complexes 1,8,2 [HgRz], and [Hg(R)ClleJowere prepared following previously described procedures. [Pd(r*-R')(bpy)]C104 (2). Complex 1 (181 mg, 0.37 mmol) and AgClO4 (76 mg, 0.37 mmol) were mixed in dichloromethane (15cm3), and the mixture was stirred for 2.5 h. The precipitated solid was filtered and extracted with 5-cm3portions of dichloromethane, until the extract was colorless. The combinedextracts were evaporated to ca. 5 cm3 and diethyl ether was added, precipitating2. Yield: 95 mg, 46 % . Complex2 has spectroscopic properties the same as those obtained previously.2b [Hg(RN)a] (3). [HgRz] (257mg,0.43mmol)and n-decylamine (141 mg, 0.87 mmol) were reacted in boiling toluene for 6 h. The mixture was evaporated to dryness under vacuum and the residue extracted with n-hexane. The extract was filtered over anhydrous MgSO4 and the solvent evaporated to give an oil which was washed with methanol and dried under vacuum to afford liquid 3. Yield 231 mg, 62%. IR. v(CN) 1640 cm-l. lH NMR (CDCla, 6): 8.42 (8, CH=N, 1H), 6.96 (8, C a , 1H), 4.04,4.02, and 4.01 (8, MeO, 3 H), 3.56 (m, CHzN, 2 H), 1.5-1.0 (m, br, (CHZ)~, 16 H), 0.87 (t, Me-(CHZ)g, 3 H, 'JHH = 6 Hz). [€Ig(RNN)Cl] (4). [Hg(R)Cll (1.56g, 3.6 mmol) and o-phenylenediamine (0.39 g, 3.6 mmol) were mixed in toluene (40 cm3), and the mixture boiled for 5 h. The solvent was evaporated and the residue recrystallized from dichloromethane/hexane giving yellow 4. Yield: 0.99 g, 53 %. Mp: 138 "C. I R v(NH) 3470 and (9) Vicente, J.; Abad, J. A.; Sandoval, A. J . Organomet. Chem. 1992, 434,l. (10) Sharp, T.M.J. Chem. SOC.1937, 852.
3380, v(Hg-Cl) 330 cm-'. lH NMR (CDCh, 6): 8.47 (8,CH=N, 1H), 7.3-7.2,7.15-7.0,6.95-6.8, and 6.75-6.6 (m, CsH, C A , and NH2, 7 H), 3.95, 3.94, and 3.93 (s, MeO, 3 H). Anal. Calcd for Cl6H17NzC1HgO,q: C, 36.86; H, 3.29; N, 5.37. Found C, 36.66; H, 3.72; N, 5.43. [Pd(rZ-RN)(p-Cl)]r(5). The mercurial3 (194 mg, 0.22 mmol) and [PdClz(MeCN)21 (58 mg, 0.22 mmol) were reacted in dichloromethane (10 cm3)for 3 h. The mixture was filtered over anhydrous MgSO4 and the solution concentrated (3 cm3). By addition of diethyl ether yellow 5 precipitated. Yield 93 mg, 89%. Mp: 150 "C. I R v(CN) 1615 cm-'. 'H NMR (CDCb, 6): 7.69 (s,CH=N, 1H),6.67 (s,CeH,lH), 3.82 (s,MeO,3 H),3.80 (8, MeO, 6 H), 3.45 (m, CHzN, 2 H), 1.79 and 1.25 (m, br, (CH&, 16 H), 0.87 (t, Me-(CHz)g, 3 H, 3 J = ~6 Hz). Anal. Calcd for CmH3zNClO3Pd C, 50.35; H, 6.53; N, 2.71. Found C, 50.43; H, 6.77; N, 2.94. [Pd(rs-RNN)(PP4)]CF~S0s(6). The mercurial 4 (33 mg, 0.06 mmol) and [PdClz(MeCN)21(16mg, 0.06 mmol) were reacted in dichloromethane (10 cm3) overnight. The solvent was evaporated, acetone (10 cm3), K(CF3SO3) (12 mg, 0.06 mmol), and PPh3 (16mg, 0.06 mmol) were added, and the mixture was stirred for 2 h. The mixture was filtered over Celite, and the solvent was evaporated, the residue being recrystallized from dichloromethane/ diethyl ether to give yellow 6. Yield: 33 mg, 66%. Mp: 165 OC dec. AM (acetone): 90 i2-l cm2mol-'. I R v(NH) 3220,3190,and 3150 cm-l. lH NMR (CDC13,6): 8.64 (d, CH=N, 1H, JPH= 9 Hz), 8.0-7.6, 7.5-7.3,7.2-7.0, 7.0-6.8, and 6.8-6.6 (m, Ph, C A , CeH, 20 H), 4.34 (s, NH2,2 HI, 3.90,3.51, and 2.62 (8,MeO, 3 H). 31PNMR (CDCls, 6): 34.0. Anal. Calcd for C S H ~ Z N Z F ~ O ~ S P P ~ C, 52.35; H, 4.02; N, 3.49. Found C, 51.82; H, 4.36; N, 3.79. [Pd(r*-RN)(bpy)]ClO, (7). AgClO, (18mg,O.O85mmol) and 5 (40 mg, 0.085 mmol) were reacted in acetone (10 cm3) for 30 min. The mixture was filtered, bpy (13 mg, 0.085 mmol) was added to the solution which was concentrated, and diethyl ether was added to precipitate 7 as a yellow solid. Yield 43 mg, 73%. Mp: 128 "C. AM(acetone): 123 i2-l cm2mol-l. I R v(CN) 1598, 1610 cm-1. 1H NMR (CDC13, 6): 8.85, 8.6, 8.5, 8.2, 7.7, and 7.4 (m, br, bpy) 8.04 (8, CH=N, 1H), 6.91 (8,CsH, 1 H), 3.89,3.82, = 7 Hz) 1.73, and 3.60 (8, MeO, 3 H), 3.73 (t, CHzN, 2 H, VHH 1.35, and 1.2 (m, br, (CH2)8,16 HI, 0.77 (t,Me-(CHz)e, 3 H, 3 J ~ = 7 Hz). Anal. Calcd for CmH~N&107Pd: C, 51.73; H, 5.79; N, 6.03. Found C, 51.56; H, 5.83; N, 6.02. [Pd(Z-R'NN)Cl] (9). o-Phenylenediamine (20 mg, 0.18 mmol) was added to a solution of 8 (61 mg, 0.09 mmol) in dichloromethane (10 cm3) and reacted for 30 min. The yellow precipitate of 9 was collected by filtration and washed with dichloromethane (2 X 3 cm9 and diethyl ether (2 X 3 cm3). Yield: 40 mg, 52%. Mp: 261 OC dec. IR: v(NH) 3210,3170,3130, and 3090 cm-l. Anal. Calcd for Cl,J-I17N2ClO3Pd: C, 44.99: H, 4.01; N, 6.56. Found C, 45.09; H, 4.21; N, 6.85. [Pd(Ka-R'NN)(PPha)]CFsSOs(6'). Complex 9 (37 mg, 0.09 mmol) was reacted with PPh3 (23 mg, 0.09 mmol) and K(CF3SO3) (16 mg, 0.09 mmol) in acetone (10 cm3) for 30 min. The solvent was exaporated and the residue recrystallized from dichloromethane/diethyl ether giving yellow 6'. Yield 45 mg, 64%. Mp: 207 OC dec. AM (acetone): 131 i2-l cm2 mol-'. IR: v(NH) 3210 (br) cm-'. lH NMR (CDCls, 6): 8.74 (d, CH=N, 1
H,Jp~=gH~),7.&7.6,7.54,and7.4-7.1(m,Ph,C6H1,19H),5.68 (d, CsH, 1H, JPH 5 Hz), 4.75 (8,NHz, 2 H), 4.05,3.75, and 2.94 (s, MeO, 3 H). NMR (CDCla, 6): 36.7. Anal. Calcd for C=HszNzF3O&PPd: C, 52.35; H, 4.02; N, 3.49. Found C, 52.07; H, 4.39; N, 3.63. [Hg(RMe)Cl] (10). 3,4,5-Trimethoxyacetphenone (5.0g, 24 mmol), Hg(MeCO2)z (7.6 g, 24 mmol), and acetic acid (2.5 cm3) in ethanol were refluxed for 4 h. The mixture was poured into aqueous KC1. The precipitate was filtered off, washed with water and air dried to give 10. Yield: 8.0 g, 75%. Mp: 224 "C. I R v(C0) 1645 cm-l. lH NMR (CDC13, 6): 7.38 (8, CsH, 1H), 3.96, 3.95, and 3.89 (8, MeO, 3H), 2.67 (8, MeCO, 3 HI. Mass spectrum: m/z (% abundance) 446 (M+,42), 431 (M+- C1,25), 202 (Hg+,54), 179 ([M + HI+ - HgCl - OMe, 621,151 (57), 123 (60), 93 (100). Anal. Calcd for C11H&lHgO,: C, 29.67; H, 2.94. Found: C, 29.22; H, 3.15.
4154 Organometallics, Vol. 12, No. 10, 1993
Vicente et al.
Table I. Crystal Data for Compounds 6, 6', and 16 at -95 "C 6'.1 .SC4HloO
16.CH2C12 C ~ I H ~ ~ F ~ N Z O ~ . S P P ~ SC27H27C12F3N207PdS
yellow tablet 0.: X 0.25 X 0.1 P1
Dx(Mg m-3)
F(000) P
("-9
transmissions (min/max) 2emx (ded
no. of reflns measd ind Rint
R, (P. all reflns) R (& > 4 4 F ) ) no. of params
S max A/u max Ap (e A-3)
914.2 yellow prism 0.6 X 0.2 X 0.15
€%IC
751.9 yellow plate 0.9 X 0.1 X 0.03 P2dn
11.228(6) 16.818(6) 22.650(9)
12.199(4) 7.801(3) 30.910(11)
12.452(3) 12.754(3) 13.275(3) 111.34(2) 104.21(2) 95.32(2) 1864.5 2 1.582 900 0.80 0.85497 50
101.61(4)
95.80(3)
4190 4 1.449 1884 0.60 0.89-0.93 50
2927 4 1.720 1528 0.96 no abs corr 50
808 1 6583 0.033 0.109 0.040 472 1.os
