C O M M U N I C A T I O N S
Scheme 2
T.A. thanks MIT’s UROP (Undergraduate Research Opportunities
Program) for funding. The authors thank a referee for drawing
attention to ref 12.
Supporting Information Available: Details of the X-ray crystal-
lography study, synthetic procedures and characterization data for the
reported compounds, and 31P NMR chemical shifts calculations (PDF,
CIF). This material is available free of charge via the Internet at http://
pubs.acs.org.
References
(1) Peters, J. C.; Odom, A. L.; Cummins, C. C. Chem. Commun. 1997, 20,
1995.
(2) Greco, J. B.; Peters, J. C.; Baker, T. A.; Davis, W. M.; Cummins, C. C.;
Wu, G. J. Am. Chem. Soc. 2001, 123, 5003.
(3) Mindiola, D. J.; Cummins, C. C. Angew. Chem., Int. Ed. Engl. 1998, 37,
Figure 1. Structural drawing of [(1-CPPh)Na(Et2O)(THF)]2 with thermal
ellipsoids at the 35% probability level. Selected interatomic distances (Å)
and angles (deg): Mo-C(1), 1.762(5); P-C(1), 1.771(5); P-C(41), 1.826-
(5); Mo-C(1)-P, 171.0(3); C(1)-P-C(41), 106.0(2).
945.
(4) Mindiola, D. J.; Tsai, Y.-C.; Hara, R.; Chen, Q.; Meyer, K.; Cummins,
C. C. Chem. Commun. 2001, 1, 125.
(5) For a review on arene extrusion reactions, see: Wong, H. N. C.; Hg, T.
K.; Wong, T. Y. Heterocycles 1983, 20, 1815.
(6) Peters, J. C.; Johnson, A. R.; Odom, A. L.; Wanandi, P. W.; Davis, W.
M.; Cummins, C. C. J. Am. Chem. Soc. 1996, 118, 10175.
(7) Agapie, T.; Diaconescu, P. L.; Mindiola, D. J.; Cummins, C. C. Submitted
for publication.
(8) Ar ) 3,5-C6H3Me2 for both complexes 1 and 2.
(9) Kim, E.; Odom, A. L.; Cummins, C. C. Inorg. Chim. Acta 1998, 278,
103.
(10) For a structurally characterized niobium-7-norbonadienyl complex see:
Mercier, R.; Douglade, J.; Amaudrut, J.; Sala-Pala, J.; Guerchais, J. E. J.
Organomet. Chem. 1983, 244, 145.
(11) For solution reactions involving intermediate 7-norbornadienyl radical,
see: (a) Synthesis of 7-tert-butoxynorbornadiene from norbornadiene, tert-
butyl perbenzoate, and CuBr in refluxing benzene (26% isolated yield):
Story, P. R. J. Org. Chem. 1961, 26, 287. Story, P. R. J. Am. Chem. Soc.
1960, 82, 2085. (b) Reduction of 7-bromonorbornadiene with stannane
in n-hexane at 130 °C in the presence of nonstoichiometric amounts of
di-tert-butyl peroxide (72% conversion to norbornadiene): Sugiyama, Y.;
Kawamura, T.; Yonezawa, T. J. Am. Chem. Soc. 1978, 100, 6525. For a
low-temperature solution EPR study of the 7-norbornadienyl radical see:
Sugiyama, Y.; Kawamura, T.; Yonezawa, T. Chem. Commun. 1978, 804.
However, attempts to study the 7-norbornadienyl radical in adamantane
matrix generated the tropylium radical: Sustmann, R.; Brandes, D.; Lange,
F.; Nu¨chter, U. Chem. Ber. 1985, 118, 3500.
Figure 2. HOMO-3 molecular orbital displaying π bonding interaction
between Mo, C, and P atoms.
synthesis the versatile and interesting methylidyne complex 1-CH.
The methine transfer reaction relies on the propensity of titanium
amide 2 to effect halogen atom abstraction in concert with the
selectivity of molybdenum amide 1 to serve as a trap for the
7-norbornadienyl radical.16 This overall hypothesis remains to be
validated by further detailed study, but in the present case it has
permitted large-scale access to 1-CH and the corresponding
potassium salt (1-CK)2 for elaboration to an unusual phosphorus
derivative, the chemistry of which promises to be of substantial
fundamental interest. With this work methine transfer assumes its
rightful place alongside nitrogen, oxygen, and halogen atom transfer
reactions in the context of inorganic synthesis.
(12) For η2-bound phosphaisocyanide complexes bridging two metal centers
see: Konze, W. V.; Young, V. G.; Angelici, R. J. Organometallics 1999,
18, 258 and references therein.
(13) Attempts to generate neutral 1-CPPh by chlorine abstraction with 2 from
1-CP(Cl)Ph or by mixing equivalent amounts of 1-CP(Cl)Ph and
1-CPPhNa(Et2O)(THF) resulted in formation of diamagnetic (1-CPPh)2
dimer. See Supporting Information for experimental details.
(14) The 31P chemical shift in a THF-d8 solution has an intermediate value of
103.5 ppm.
(15) See the Supporting Information for details and references on the DFT
calculations, which were carried out using the Amsterdam Density
Functional (ADF) suite of programs.
(16) Low yield formation of 1-CH upon treatment of 1 with CH2Cl2 has been
reported previously: Fu¨rstner, A.; Mathes, C.; Lehmann, C. W. J. Am.
Chem. Soc. 1999, 121, 9453.
Acknowledgment. For support of this work, the authors are
grateful to the National Science Foundation (CHE-9988806), the
Packard Foundation (Fellowship to C.C.C., 1995-2000), and the
National Science Board (Alan T. Waterman award to C.C.C., 1998).
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