Beilstein J. Org. Chem. 2015, 11, 1541–1546.
4
.
Grela, K.; Harutyunyan, S.; Michrowska, A. Angew. Chem., Int. Ed.
more sterically-demanding diene 10 afforded the trisubstituted
olefin cyclized product with high 93% isolated yield. Catalyst
4
1
9
a was also efficient regarding the cyclization of enynes 12 and
4 and the desired diene products were obtained with 89 and
0% isolated yields, respectively. Finally, the cross metathesis
5.
6.
7.
8.
Clavier, H.; Caijo, F.; Borré, E.; Rix, D.; Boeda, F.; Nolan, S. P.;
reaction between allylbenzene and ethyl acrylate afforded the
Nelson, J. D.; Queval, P.; Rouen, M.; Magrez, M.; Toupet, L.; Caijo, F.;
Monsaert, S.; Lozano Vila, A.; Drozdzak, R.; Van Der Voort, P.;
desired internal E-olefin with 62% yield.
Conclusion
We described the synthesis and characterization of three novel
latent 2nd generation indenylidene-based precatalysts for olefin
metathesis reactions. A picolinate moiety was successfully
inserted into SIMes- and SIPr-containing architectures,
affording unprecedented mono-picolinate complexes. Whilst
SIMes-containing species 2 was identified as a mixture of
isomers with a low stability in solution, compounds 4a and 4b,
featuring the bulkier ancillary ligand SIPr, appeared as highly
stable, well-defined species. These species were shown to acti-
vate in the presence of a Brønsted acid and precatalysts 2 and
Morin, Y.; Gauvin, R. M. Schiff Base Catalysts and Other Related
Latent Systems for Polymerization Reactions. In Olefin Metathesis:
Theory and Practice; Grela, K., Ed.; John Wiley & Sons: Hoboken,
2014; pp 453–471.
9.
1
4
a showed an excellent latent behaviour. The best reaction rates
1
were obtained in the RCM of DEDAM with complex 4a after
activation by HCl addition. The versatility of the catalyst was
subsequently demonstrated in RCM, CM and enyne metathesis
reactions.
13.van der Schaaf, P. A.; Mühlbach, A.; Hafner, A.; Kolly, R. Heterocyclic
ligand containing ruthenium and osmium catalysts. WO Patent
WO99/29701, Dec 4, 1999.
1
4.Denk, K.; Fridgen, J.; Hermann, W. A. Adv. Synth. Catal. 2002, 344,
66–670.
6
1
Supporting Information
And references cited therein.
Supporting Information File 1
1
Full experimental procedures and detailed analytical data
1
See for the reaction with tetrahydro-2-furoic acid.
1
1
2
Acknowledgements
2
This work was supported by the Agence Nationale de la
Recherche (ANR) (ANR-12-CD2I-0002 Cflow-OM), Oméga
Cat System and the Association Nationale de la Recherche et la
Technologie (ANRT, grant to A.D.). M.M. and O.B. thank the
Centre National de la Recherche Scientifique (CNRS) and the
Ecole Nationale Supérieure de Chimie de Rennes (ENSCR).
21.Torborg, C.; Szczepaniak, G.; Zieliński, A.; Malińska, M.; Woźniak, K.;
2
See for an example with silver salts.
2
2
References
1.
2.
3.
Grela, K., Ed. Olefin Metathesis: Theory and Practice; John Wiley &
Sons: Hoboken, 2014.
1
Wakamatsu, H.; Blechert, S. Angew. Chem., Int. Ed. 2002, 41,
See for an example with potassium salts.
25.Herbert, M. B.; Lan, Y.; Keitz, B. K.; Liu, P.; Endo, K.; Day, M. W.;
1545