ORGANIC
LETTERS
2008
Vol. 10, No. 5
777-780
Diene−Titanium Complexes as Synthetic
Intermediates for the Construction of
Three- or Five-Membered Carbocycles
Philippe Bertus,*,† Christine Menant, Chloe´ Tanguy, and Jan Szymoniak*
ICMR - UMR 6229, CNRS - UniVersite´ de Reims Champagne-Ardenne, BP 1039,
51687 Reims Cedex 2, France
philippe.bertus@uniV-lemans.fr; jan.szymoniak@uniV-reims.fr
Received December 3, 2007
ABSTRACT
It has been shown that diene−titanium complexes exhibit substrate-dependent 1,2- or 1,4-dicarbanion reactivity. On this basis, 3-cyclopen-
tenylamines and spiro-vinylcyclopropane lactams were easily prepared by using homoallylic Grignard reagents, Ti(O-i-Pr)4, and nitriles or
cyanoesters, respectively.
Titanacyclopropanes (A1), which can also be considered as
π-complexes (A2), are typically formed by transmetalation
and a successive â-fragmentation (Scheme 1).1 These putative
Following the discovery of the Kulinkovich reaction, Ti-
(II) chemistry has been widely developed,1 particularly due
to the 1,2-dicarbanion pattern of titanacyclopropanes. In
addition, exchange of alkenes, imines, or alkynes starting
from the initial Ti(II)-alkene complex has broadened the
scope of the cyclopropanation and other reactions.5
Scheme 1
In contrast to A, reactions of diene-titanium complexes
B have been less investigated.6-10 This species can be
(4) (a) Bertus, P.; Szymoniak, J. Chem. Commun. 2001, 1792. (b) Bertus,
P.; Szymoniak, J. Synlett 2007, 1346.
(5) Some recent examples: Alkenes: (a) Keaton, K. A.; Phillips, A. J.
Org. Lett. 2007, 9, 2717. (b) Quan, L. G.; Kim, S.-H.; Lee, J. C.; Cha, J.
K. Angew. Chem., Int. Ed. 2002, 41, 2160. Imines: (c) Takahashi, M.;
Micalizio, G. C. J. Am. Chem. Soc. 2007, 129, 7514. (d) Fukuhara, K.;
Okamoto, S.; Sato, F. Org. Lett. 2003, 5, 2145. Alkynes: (e) Bahadoor, A.
B.; Flyer, A.; Micalizio, G. C. J. Am. Chem. Soc. 2005, 127, 3694. (f)
Suzuki, D.; Nobe, Y.; Watai, Y.; Tanaka, R.; Takayama, Y.; Sato, F.; Urabe,
H. J. Am. Chem. Soc. 2005, 127, 7474.
(6) (a) Williams, C. M.; Chaplinski, V.; Schreiner, P. R.; de Meijere, A.
Tetrahedron Lett. 1998, 39, 7695. (b) de Meijere, A.; Williams, C. M.;
Kourdioukov, A.; Sviridov, S. V.; Chaplinski, V.; Kordes, M.; Savchenko,
A. I.; Stratmann, C.; Noltenmeyer, M. Chem. Eur. J. 2002, 8, 3789.
(7) (a) Urabe, H.; Kasatkin, A.; Sato, F. Chem. Commun. 1996, 197. (b)
Urabe, H.; Takeda, T.; Sato, F. Tetrahedron Lett. 1996, 37, 1253. (c) Urabe,
H.; Mitsui, K.; Ohta, S.; Sato, F. J. Am. Chem. Soc. 2003, 125, 6074.
(8) Laroche, C.; Bertus, P.; Szymoniak, J. Chem. Commun. 2005, 3030.
intermediates are involved in the Kulinkovich hydroxycy-
clopropanation of esters2 as well as in the related syntheses
of tertiary3 and primary4 cyclopropylamines from amides and
nitriles, respectively.
† Present address: UMR 6011 - UCO2M, CNRS - Universite´ du Maine,
72085 Le Mans cedex 9, France.
(1) (a) Kulinkovich, O. G.; de Meijere, A. Chem. ReV. 2000, 100, 2789.
(b) Sato, F.; Urabe, H.; Okamoto, S. Chem. ReV. 2000, 100, 2835.
(2) (a) Kulinkovich, O. G.; Sviridov, S. V.; Vasilevsky, D. A. Synthesis
1991, 234. (b) Kulinkovich, O. G. Eur. J. Org. Chem. 2004, 4517.
(3) (a) Chaplinski, V.; de Meijere, A. Angew. Chem., Int. Ed. Engl. 1996,
35, 413. (b) de Meijere, A.; Kozhushkov, S. I.; Savchenko, A. I. J.
Organomet. Chem. 2004, 689, 2033.
10.1021/ol702917c CCC: $40.75
© 2008 American Chemical Society
Published on Web 01/30/2008