80
R.U. Claessen et al. / Journal of Organometallic Chemistry 689 (2004) 71–81
dithiane anions can be used to prepare sila-b-diketones,
our previously reported method involving the conden-
sation of the lithium salt of an acetyltrialkylsilane with
an activated carbonyl compound, such as an acyl chlo-
ride, is far superior with regard to ease of preparation,
yields, and the use of less toxic reagents [8–11].
References
[1] T.T. Kodas, M.J. Hampden-Smith (Eds.), The Chemistry of
Metal CVD, VCH Publishers, New York, 1994.
[2] J.T. Spencer, Prog. Inorg. Chem. 41 (1994) 145.
[3] S.P. Murarka, S.W. Hymes, Crit. Rev. Solid State Mater. Sci. 20
(1995) 87.
During the investigation, we characterized a second
structural polymorph of Cu(tmshd)2 (4). This mono-
clinic polymorph was site disordered like the previously
characterized, orthorhombic polymorph [9], and had
similar bonding parameters in its coordination sphere.
Also, the calculated density of the monoclinic modifi-
cation, like the orthorhombic one, was lower than ex-
pected based on molecular mass considerations,
probably due to inefficient packing of the molecules in
the solid-state.
[4] T.J. Marks, Pure Appl. Chem. 67 (1995) 313.
[5] P. Doppelt, Coord. Chem. Rev. 178–180 (1998) 1785.
[6] M.J. Hampden-Smith, T.T. Kodas, A. Ludviksson, in: L.V.
Interrante, M.J. Hampden-Smith (Eds.), Chemistry of Advanced
Materials, Wiley–VCH, New York, 1998, p. 143.
[7] T.N. Theis, IBM J. Res. Develop. 44 (2000) 379.
[8] R.U. Claessen, J.T. Welch, P.J. Toscano, K.K. Banger, A.M.
Kornilov, E.T. Eisenbraun, A.E. Kaloyeros, Mater. Res. Soc.
Symp. Proc. 612 (2000) D6–8.
[9] K.K. Banger, A. Kornilov, R.U. Claessen, E.T. Eisenbraun, A.E.
Kaloyeros, P.J. Toscano, J.T. Welch, Inorg. Chem. Commun. 4
(2001) 496.
We made attempts to apply the 1,3-dithiane method
for the synthesis of the disilylated b-diketone, 2,2,6,6-
tetramethyl-2,6-disilaheptane-3,5-dione. We were able to
prepare the desired precursor, 2; 20-methylenebis(2-trim-
ethylsilyl-1,3-dithianyl) (5), as well as a monosilylated
compound, methylene-2-(1,3-dithianyl)-20-(2-trimethyl-
silyl-1,3-dithianyl) (6). However, neither 5 nor 6 could be
deprotected by any of several deprotection protocols to
give the corresponding b-dicarbonyl compound. The
solid-state structures of 5 and 6 were determined and
compared to that of bis(trimethylsilyl)-2; 20-bi-1,3-dithi-
ane (3), an impurity that was isolated in the preparation
of tmshdH by the 1,3-dithiane method. Strong stereo-
electronic effects involving repulsions between sulfur
atom lone pairs, as well as significant steric interactions,
were apparent, particularly in the structures of 3 and 5,
which contain long C–Si bonds and severely distorted
torsion and bond angles.
[10] S. Higashiya, K.K. Banger, S.C. Ngo, P.N. Lim, P.J. Toscano,
J.T. Welch, Inorg. Chim. Acta 351 (2003) 291.
[11] K.K. Banger, S.C. Ngo, S. Higashiya, R.U. Claessen, K.S.
Bousman, P.N. Lim, P.J. Toscano, J.T. Welch, J. Organomet.
Chem. 678 (2003) 15.
[12] E.J. Corey, D. Seebach, R. Freedman, J. Am. Chem. Soc. 89
(1967) 434.
[13] A.G. Brook, J.M. Duff, P.F. Jones, N.R. Jones, J. Am. Chem.
Soc. 89 (1967) 431.
[14] E.J. Corey, D. Seebach, Angew. Chem. Int. Ed. Engl. 4 (1965)
1075.
[15] E.J. Corey, D. Seebach, Angew. Chem. Int. Ed. Engl. 4 (1965)
1077.
[16] D. Seebach, E.J. Corey, J. Org. Chem. 40 (1975) 231.
[17] R.C. Cambie, G.R. Clark, S.R. Gallagher, P.S. Rutledge, J.
Organomet. Chem. 342 (1988) 315.
[18] T.W. Greene, P.G.M. Wuts (Eds.), Protective Groups in Organic
Synthesis, third ed., Wiley–Interscience, New York, 1999, pp. 333–
344.
[19] A. Bruce, J.L. Corbin, P.L. Dahlstrom, J.R. Hyde, M. Minelli,
E.I. Stiefel, J.T. Spence, J. Zubieta, Inorg. Chem. 21 (1982) 917.
[20] Bruker Analytical X-ray Instruments, Inc., Madison, WI, USA,
2001.
[21] Y. Apeloig, I. Zharov, D. Bravo-Zhivotovskii, Y. Ovchinnikov,
Y. Struchkov, J. Organomet. Chem. 499 (1995) 73.
[22] D.I. Gasking, G.H. Whitham, J. Chem. Soc. Perkin Trans. 1
(1985) 409.
5. Supplementary material
Full lists of crystallographic data for 3 (CCDC-
149097), 4 (CCDC-215184), 5 (CCDC-215185), and 6
(CCDC-215186), including atomic coordinates, bond
lengths and angles, and anisotropic thermal parameters
have been deposited with the Cambridge Crystallo-
graphic Data Centre. Copies of this information may be
obtained from The Director, CCDC, 12 Union Road,
Cambridge, CB2 1EZ, UK (fax: +44-1233-336033;e-
[23] J.-B. Verlhac, H. Kwon, M. Pereyre, J. Organomet. Chem. 437
(1992) S13.
[24] J.-P. Bouillon, C. Portella, Tetrahedron Lett. 38 (1997) 6595.
[25] M. Prato, U. Quintily, G. Scorrano, A. Sturaro, Synthesis (1982)
679.
[26] M. Kamata, H. Otogawa, E. Hasegawa, Tetrahedron Lett. 32
(1991) 7421.
[27] K. Tanemura, H. Dohya, M. Imamura, T. Suzuki, T. Horaguchi,
Chem. Lett. (1994) 965.
[28] M. Fetizon, M. Jurion, J. Chem. Soc. Chem. Commun. (1972)
382.
[29] R. Ballini, M. Petrini, Synthesis (1990) 336.
[30] W.H. Watson, W.W. Holley, Croat. Chem. Acta 57 (1984) 467.
[31] S. Sans-Lenain, A. Gleizes, Inorg. Chim. Acta 211 (1993) 67.
[32] S. Patnaik, T.N. Guru Row, L. Raghunathan, A. Devi, J.
Goswami, S.A. Shivashankar, S. Chandrasekaran, W.T. Robin-
son, Acta Crystallogr. Sect. C: Cryst. Struct. Commun. C52 (1996)
891.
Acknowledgements
We thank the New York State Science and Tech-
nology Foundation and Center for Advanced Thin Film
Technology for financial support.
[33] D. Seebach, Synthesis (1990) 17.