Abstract
Motivated by our preliminary results on Cp2 TiF2 -catalysed
1,4-hydrosilylation of monosubstituted dienes, we assessed the performance
of several titanium complexes for the hydrosilylation of 2,3-dimethylbutadiene,
a representative bulky diene. An open-bent titanocene complex [Me2 C(C5 H4 )2 TiMe2 ] performed
the best and proved to be efficient for the hydrosilylation of a
variety of substrates such as disubstituted dienes, activated alkenes,
and even an acetylene.
Key words
hydrosilylation - titanium - diene - allylsilane - homogeneous catalysis
References and Notes
Reviews:
1a
Sakurai H.
Pure
Appl. Chem.
1982,
54:
1
1b
Hosomi A.
Acc.
Chem. Res.
1988,
21:
200
1c
Langkopf E.
Shinzer D.
Chem. Rev.
1995,
95:
1375
1d
Fleming I.
Barbero A.
Walter D.
Chem.
Rev.
1997,
97:
2063
1e
Chabaud L.
James P.
Landais Y.
Eur.
J. Org. Chem.
2004,
3173
2
Sarkar TK.
Synthesis
1990,
1101
For recent examples of allylsilane
syntheses, see:
3a
Terao J.
Watabe H.
Watanabe H.
Kambe N.
Adv. Synth. Catal.
2004,
346:
1674
3b
Nii S.
Terao J.
Kambe N.
Tetrahedron
Lett.
2004,
45:
1699
3c
Suginome M.
Iwanami T.
Ohmori Y.
Matsumoto A.
Ito Y.
Chem.
Eur. J.
2005,
11:
2954
3d
Gerdin M.
Moberg C.
Org. Lett.
2006,
8:
2929
3e
Hayashi S.
Hirano K.
Yorimitsu H.
Oshima K.
J. Am. Chem. Soc.
2007,
129:
12650
3f
Kacprzynski MA.
May TL.
Kazane SA.
Hoveyda AH.
Angew.
Chem. Int. Ed.
2007,
46:
4554
3g
Moser R.
Nishikata T.
Lipshutz BH.
Org.
Lett.
2010,
12:
28
3h
Vyas D.
Oestreich M.
Angew. Chem. Int. Ed.
2010,
49:
8513
3i
Li D.
Tanaka T.
Ohmiya H.
Sawamura M.
Org. Lett.
2010,
12:
3344
3j
Wu J.
Chen Y.
Panek JS.
Org.
Lett.
2010,
12:
2112
4a
Speier JL.
Adv. Organomet. Chem.
1979,
17:
441
4b
Marciniec B.
Hydrosilylation:
A Comprehensive Review on Recent Advances
Springer;
Berlin:
2009.
p.3
5a
Ojima I.
Kumagai M.
J.
Organomet. Chem.
1978,
157:
359
5b
Ojima I.
J.
Organomet. Chem.
1977,
134:
C1
5c
Ojima I.
Kumagai M.
J. Organomet. Chem.
1977,
134:
C6
5d
Hayashi T.
Kebeta K.
Tetrahedron Lett.
1985,
26:
3023
5e
Tsuji T.
Hara M.
Ohno K.
Tetrahedron
1994,
30:
2143
5f
Gustafsson M.
Frejd T.
J. Chem. Soc., Perkin Trans.
1
2002,
102
5g
Gustafsson M.
Frejd T.
J. Organomet. Chem.
2004,
689:
438
6
Bareille L.
Becht S.
Cui J.
Le Gendre P.
Moïse C.
Organometallics
2005,
24:
5802
7 This process has been used by Leighton
for the synthesis of a spongistatin 1 fragment, see: Spletstoser JT.
Zacuto
MJ.
Leighton JL.
Org. Lett.
2008,
10:
5593
For dialkyl metallocene catalysed
hydrosilylation of alkenes, alkynes and their derivatives, see:
8a
Takahashi T.
Hasegawa M.
Suzuki N.
Saburi M.
Rousset CJ.
Fanwick PE.
Negishi E.
J.
Am. Chem. Soc.
1991,
113:
8564
8b
Kesti MR.
Waymouth RM.
Organometallics
1992,
11:
1095
8c
Harrod JF.
Yun SS.
Organometallics
1987,
6:
1381
8d
Corey JY.
Zhu XH.
Organometallics
1992,
11:
672
8e
Harrod JF.
Coord. Chem. Rev.
2000,
493
8f
Takahashi T.
Bao F.
Gao G.
Ogasawara M.
Org. Lett.
2003,
5:
3479
8g
Ura Y.
Gao G.
Bao F.
Ogasawara M.
Takahashi T.
Organometallics
2004,
23:
4804
9 Roullier, L.; Mugnier, Y.; Pousson,
E.; Moïse, C.; Richard, P.; Le Gendre, P.; Harvey,
P. H. unpublished results.
The dihedral angle between the
two Cp rings in [Me2 C(Cp2 TiCl2 )] is
about 9˚ bigger than that of Cp2 TiCl2 , indicating
a more open geometry:
10a
Shaltout MR.
Corey JY.
Rath NP.
J. Organomet. Chem.
1995,
503:
205
10b
Wang B.
Mu B.
Deng X.
Cui H.
Xu S.
Zhou X.
Zou F.
Li Y.
Yang L.
Li Y.
Hu Y.
Chem.
Eur. J.
2005,
11:
669
11 The efficacy of Cp2 TiF2 in
the hydrosilylation of mono-substituted 1,3-dienes prompted us to
assess the catalytic performance of the difluoro-ansa-titanocene.
Unfortunately, in our hands activation of the ansa-difluorotitanocene precatalyst
was not possible.
12 The geometry of 2 was
determined to be E by comparison of the
NMR spectra with those reported previously, see ref. 5.
13 The E configuration
of 5 and 6 was
unambiguously determined by NOESY NMR experiments.
14
Aitken CT.
Harrod JF.
Samuel E.
J.
Am. Chem. Soc.
1986,
108:
4059
15a
Buch F.
Brettar J.
Harder S.
Angew. Chem. Int. Ed.
2006,
45:
2741
15b
Ruspic C.
Spielmann J.
Harder S.
Inorg.
Chem.
2007,
46:
5320
16
Lappert MF.
Picket CJ.
Riley PI.
Yarrow PIW.
J.
Chem. Soc., Dalton Trans.
1981,
805
17
Le Gendre P.
Richard P.
Moïse C.
J.
Organomet. Chem.
2000,
605:
151