TY - JOUR
T1 - Well-defined silica-supported Mo-alkylidene catalyst precursors containing one OR substituent
T2 - Methods of preparation and structure-reactivity relationship in alkene metathesis
AU - Rendón, Nuria
AU - Berthoud, Romain
AU - Blanc, Frédéric
AU - Gajan, David
AU - Maishal, Tarun
AU - Basset, Jean Marie
AU - Copéret, Christophe
AU - Lesage, Anne
AU - Emsley, Lyndon
AU - Marinescu, Smaranda C.
AU - Singh, Rojendra
AU - Schrock, Richard R.
PY - 2009/5/11
Y1 - 2009/5/11
N2 - The monosiloxy surface complexes [(≡SiO)Mo(≡NAr)(=CHC-Me 2R′)(OR)± (R′ = Me or Ph; OR = OtBu, OCMe(CF 3)2 or OAr) are obtained by grafting onto SiO 2-(700) either symmetric Mo-alkylidene derivatives [Mo(≡NAr)(=CHCMe2R′)(OR)2± or asymmetric derivatives, that is, with two different pendant ligands, one amido and one alkoxy/aryloxy, [Mo(≡ NAr)(=CHCMe2R′)(OR)(NC 6H8)±. The formation of these complexes was confirmed by mass-balance analysis, and infrared (IR) and NMR spectroscopies. These systems are highly efficient catalyst precursors for the metathesis of acyclic alkenes; the best results were seen when OR = OCMe-(CF3) 2. Nevertheless, they display poor performances in ring-closing metathesis, possibly due to the rigidity of the metal center (as evidenced by NMR spectroscopy), which therefore slows the rate of the metathesis.
AB - The monosiloxy surface complexes [(≡SiO)Mo(≡NAr)(=CHC-Me 2R′)(OR)± (R′ = Me or Ph; OR = OtBu, OCMe(CF 3)2 or OAr) are obtained by grafting onto SiO 2-(700) either symmetric Mo-alkylidene derivatives [Mo(≡NAr)(=CHCMe2R′)(OR)2± or asymmetric derivatives, that is, with two different pendant ligands, one amido and one alkoxy/aryloxy, [Mo(≡ NAr)(=CHCMe2R′)(OR)(NC 6H8)±. The formation of these complexes was confirmed by mass-balance analysis, and infrared (IR) and NMR spectroscopies. These systems are highly efficient catalyst precursors for the metathesis of acyclic alkenes; the best results were seen when OR = OCMe-(CF3) 2. Nevertheless, they display poor performances in ring-closing metathesis, possibly due to the rigidity of the metal center (as evidenced by NMR spectroscopy), which therefore slows the rate of the metathesis.
KW - Metathesis
KW - Molybdenum
KW - Silica supports
KW - Solid-state NMR spectroscopy
KW - Surface chemistry
UR - http://www.scopus.com/inward/record.url?scp=66149144329&partnerID=8YFLogxK
U2 - 10.1002/chem.200802465
DO - 10.1002/chem.200802465
M3 - Article
C2 - 19343757
AN - SCOPUS:66149144329
SN - 0947-6539
VL - 15
SP - 5083
EP - 5089
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 20
ER -