Organometallics
Article
zincates. See: Armstrong, D. R.; Emerson, H. S.; Hernan
Kennedy, A. R.; Hevia, E. Dalton Trans. 2014, 43, 14229−14238.
16) PhLi and ZnPh were prepared according to the literature and
employed as crystalline solids. See respectively: (a) Wehman, E.;
Jastrzebski, J. T. B. H.; Ernsting, J.-M.; Grove, D. M.; Koten, G. V. J.
Organomet. Chem. 1988, 353, 133−143. (b) Yakhvarov, D. G.;
Ganushevich, Y. S.; Sinyashin, O. G. Mendeleev Commun. 2007, 17,
́
-Gom
́
ez, A.;
2008, 10, 4705−4707. (c) Blair, V. L.; Blakemore, D. C.; Hay, D.;
Hevia, E.; Pryde, D. Tetrahedron Lett. 2011, 52, 4590−4594.
(30) Yanagisawa, S.; Ueda, K.; Taniguchi, T.; Itami, K. Org. Lett.
2008, 10, 4673−4676.
(31) Furuyama, T.; Yonehara, M.; Arimoto, S.; Kobayashi, M.;
Matsumoto, Y.; Uchiyama, M. Chem. Eur. J. 2008, 14, 10348−10356.
(32) Small amounts of biphenyl were detected in all the NMR
spectra, which is attributed to minor decomposition of the relevant
organometallic reagent under these reaction conditions.
(
2
1
(
97−198.
17) Alkali-metal zincates with the generic formulation M ZnR (M
2
4
=
alkali metal, R = anionic ligand) have been described in the literature
as higher order or tetraorgano zincates. See, for example:
a) Uchiyama, M.; Kameda, M.; Mishima, O.; Yokohama, N.; Koike,
M.; Kondo, Y.; Sakamoto, T. J. Am. Chem. Soc. 1998, 120, 4934−4946.
b) Armstrong, D. R.; Dougan, C.; Graham, D. V.; Hevia, E.; Kennedy,
(33) For selected examples see the following. (a) [(pyridi-
ne) Li(CHCl )], Li−N = 2.078 Å: Muller, A.; Marsch, M.; Harms,
3
2
(
K.; Lohrenz, J. C. W.; Boche, G. Angew. Chem., Int. Ed. 1996, 35,
1518−1520. (b) [{(pyridine) Li(OPh) } ], Li−N = 2.079 Å: Boyle,
2
2 2
(
T. J.; Pedrotty, D. M.; Alam, T. M.; Vick, S. C.; Rodriguez, M. A. Inorg.
Chem. 2000, 39, 5133−5146. (c) [{Li(NCPh )(pyridine)} ], Li−N
A. R. Organometallics 2008, 27, 6063−6070. (c) Clegg, W.; Conway,
B.; Hevia, E.; McCall, M. D.; Russo, L.; Mulvey, R. E. J. Am. Chem. Soc.
2
4
= 2.076 Å: Barr, D.; Clegg, W.; Mulvey, R. E.; Snaith, R. J. Chem. Soc.,
Chem. Commun. 1984, 226−227. (d) [{LiBr(quinoline) } ], Li−N =
2
(
009, 131, 2375−2384.
18) 1H NMR spectra and elemental analysis of [LiZnPh ] (2)
2
2
2.105 Å: Raston, C. L.; Robinson, W. T.; Skelton, B. W.; Whitaker, C.
R.; White, A. H. Aust. J. Chem. 1990, 43, 1163−1173.
3
revealed that it contains three solvating THF molecules. Thus,
although its empirical formula should be [(THF) LiZnPh ], for clarity
solvating molecules have been omitted. Similarly, for 3, on the basis of
its NMR spectra, each lithium center is solvated by two THF
molecules. However, the simplified representation Li ZnPh has been
(34) Robertson, S. D.; Kennedy, A. R.; Liggat, J. J.; Mulvey, R. E.
Chem. Commun. 2015, DOI: 10.1039/C4CC06421F.
3
3
(35) For a related interesting structure resulting from the reductive
dimerization of acridine mediated by samarium see: Labouille, S.; Nief,
F.; Le Goff, X.-F.; Maron, L.; Kindra, D. R.; Houghton, H. L.; Ziller, J.
W.; Evans, W. J. Organometallics 2012, 31, 5196−5203.
2
4
employed instead of [(THF) Li ZnPh ]. See the Experimental Section
4
2
4
in the Supporting Information for details.
19) (a) Armstrong, D. R.; Blair, V. L.; Clegg, W.; Dale, S. H.;
(
(36) Supporting this interpretation, addition of isolated crystals of 6
́
-Alvarez, J.; Honeyman, G. W.; Hevia, E.; Mulvey, R. E.; Russo,
́
to a solution of ZnPh in deuterated THF led to the formation of a
Garcıa
2
1
L. J. Am. Chem. Soc. 2010, 132, 9480−9487. (b) Armstrong, D. R.;
Garcia-Alvarez, J.; Graham, D. V.; Honeyman, G. W.; Hevia, E.;
Kennedy, A. R.; Mulvey, R. E. Chem. Eur. J. 2009, 15, 3800−3807.
complicated mixture of products. Significantly, some of the H NMR
signals match those observed in the reaction crude of acr with zincate
2 (see Figure S8 in the Supporting Information).
(
20) Krieger, M.; Geiseler, G.; Harms, K.; Merle, J.; Massa, W.;
(37) The crystal structure of 7 is a cocrystalline mixture of the donor
•
−
Dehnicke, K. Z. Anorg. Allg. Chem. 1998, 624, 1387−1388.
21) Markies, P. R.; Schat, G.; Akerman, O. S.; Bickelhaupt, F.
Organometallics 1990, 9, 2243−2247.
22) (a) Rjinberg, E.; Jastrzebski, J. T. B. H.; Boersma, J.; Kooijman,
H.; Veldman, N.; Spek, A. L.; van Koten, G. Organometallics 1997, 16,
variants [(THF)
3
Li{NC13
H -Ph }] and [(THF)(TMEDA)
8
•−
(
Li{NC H -Ph }]. Both molecules are disordered such that the
[Li{NC H -Ph }] fragments of each lie on the same crystallographic
13
8
•
−
13
8
(
sites and appear well ordered, with the THF and TMEDA groups
appearing disordered. Refinement of site occupancy factors gives a
•
−
2
239−2245. (b) Kondo, Y.; Morey, J. V.; Morgan, J. C.; Naka, H.;
0.735(3):0.265(3) ratio in favor of the [(THF) Li{NC H -Ph }]
3 13 8
Nobuto, D.; Raithby, P. R.; Uchiyama, M.; Wheatley, A. E. H. J. Am.
Chem. Soc. 2007, 129, 12734−12738. For an example of a solvent-
species
(38) For a recent example of a structurally characterized lithium
naphthalene radical anion see: Melero, C.; Guijarro, A.; Yus, M. Dalton
Trans. 2009, 1286−1289.
̈
separated ion pair tris(aryl)lithium zincate see: (c) Thiele, K.; Gorls,
H.; Seidel, W. Z. Anorg. Allg. Chem. 1998, 624, 555−556.
(
23) (a) Hope, H.; Power, P. P. J. Am. Chem. Soc. 1983, 105, 5320−
(39) Lomax, A.; Marcoux, L. S.; Bard, A. J. J. Phys. Chem. 1972, 76,
3958−3560.
5
2
(
324. (b) Strohmann, C.; Dilsky, S.; Strohfeldt, K. Organometallics
006, 25, 41−44.
(40) For other examples of acridine radical derivatives, including both
cationic and anionic species, see: (a) Tamamushi, B.; Akiyama, H.
24) (a) Barley, H. R. L.; Clegg, W.; Dale, S. H.; Hevia, E.;
Honeyman, G. W.; Kennedy, A. R.; Mulvey, R. E. Angew. Chem., Int.
Ed. Engl. 2005, 44, 6018−6021. (b) Graham, D. V.; Hevia, E.;
Kennedy, A. R.; Mulvey, R. E. Organometallics 2006, 25, 3297−3300.
̂
Trans. Faraday Soc. 1939, 35, 491−494. (b) Noyori, R.; Kato, M.;
Kawanisi, M.; Nozaki, H. Tetrahedron 1969, 25, 1125−1136.
(c) Handoo, K. L.; Cheng, J.-P.; Parker, V. D. J. Chem. Soc., Perkin
Trans. 2 2001, 1476−1480. (d) Mackiewicz, N.; Delaire, J. A.;
Rutherford, A. W.; Doris, E.; Mioskowski, C. Chem. Eur. J. 2009, 15,
3882−3888. (e) Chaudhuri, J.; Kume, S.; Jagur-Grodzinski, J.; Szwarc,
M. J. Am. Chem. Soc. 1968, 90, 6421−6425. (f) Ishikawa, M.;
Fukuzumi, S. J. Am. Chem. Soc. 1990, 112, 8864−8870. (g) Jaworski, J.
S.; Cembor, M. Tetrahedron Lett. 2000, 41, 7267−7270. (h) Taguchi,
M.; Moriyama, M.; Namba, H.; Hiratsuka, H. Radiat. Phys. Chem.
2002, 64, 115−122. (i) Fukuzumi, S.; Yuasa, J.; Satoh, N.; Suenobu, T.
J. Am. Chem. Soc. 2004, 126, 7585−7594.
(
c) Armstrong, D. R.; Herd, E.; Graham, D. V.; Hevia, E.; Kennedy, A.
R.; Clegg, W.; Russo, L. Dalton Trans. 2008, 1323−1330.
25) (a) Frohlich, H.-O.; Kosan, B.; Undeustch, B. J. Organomet.
(
Chem. 1994, 472, 1−14. (b) Wyrwa, R.; Frohlich, H.-O.; Gorls, H.
Organometallics 1996, 15, 2833−2835. (c) Edwards, A. J.; Fallaize, A.;
Raithby, P. R.; Rennie, M. A.; Steiner, A.; Verhorevoort, K. L.; Wright,
D. S. Dalton Trans. 1996, 133−137. (d) Chivers, T.; Eisler, D. J.;
Fedorchuck, C.; Schatte, G.; Tuononen, H. M.; Boere, R. T. Inorg.
Chem. 2006, 45, 2119−2131.
(
(
26) Thoennes, D.; Weiss, E. Chem. Ber. 1978, 111, 3726−3731.
(41) Gore-Randall, E.; Irwin, M.; Denning, M. S.; Goicoechea, J. M.
Inorg. Chem. 2009, 48, 8304−8316.
27) Even under prolonged times under vacuum, the H and 13C
1
5
a
NMR spectra of 3 showed resonances for the ethereal solvent THF,
suggesting that it remains coordinated to the Li atoms.
(42) Following the reported method, the reaction of acr with PhLi/
TMEDA has been carried out using excess organolithium reagent,
which could also influence the formation of 7. Supporting this
interpretation, attempts to prepare 7 using equimolar amounts of acr,
PhLi, and TMEDA were unsuccessful.
(
28) The choice of solvent seems crucial for the success of the
arylation process. When poorly coordinating toluene is employed, no
reaction is observed after 24 h under reflux conditions. Considering
our spectroscopic studies of 2 and 3 in THF solutions, these findings
suggest that the arylation reactions are promoted by solvent-separated
ion pair zincates.
(43) (a) Yamataka, H.; Kawafuji, Y.; Nagareda, K.; Miyano, N.;
Hanafusa, T. J. Org. Chem. 1989, 54, 4706−4708. (b) Yamataka, H.;
Nagareda, K.; Takatsuka, T.; Ando, K.; Hanafusa, T.; Nagase, S. J. Am.
Chem. Soc. 1993, 115, 8570−8576. (c) Yamataka, H.; Nagareda, K.;
Ando, K.; Hanafusa, T. J. Org. Chem. 1992, 57, 2865−2869.
(
29) (a) Mosrin, M.; Monzon, G.; Bresser, T.; Knochel, P. Chem.
Commun. 2009, 5615−7. (b) Wunderlich, S.; Knochel, P. Org. Lett.
I
Organometallics XXXX, XXX, XXX−XXX