A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst
نویسندگان
چکیده
منابع مشابه
Well-defined silica-supported olefin metathesis catalysts.
Two triethoxysilyl-functionalized N-heterocyclic carbene ligands have been synthesized and used to prepare the corresponding second-generation ruthenium olefin metathesis catalysts. These complexes were then grafted onto silica gel, and the resulting materials were efficient heterogeneous catalysts for a number of metathesis reactions. The solid-supported catalysts were shown to be recyclable o...
متن کاملDevelopment of the first well-defined tungsten oxo alkyl derivatives supported on silica by SOMC: towards a model of WO3/SiO2 olefin metathesis catalyst.
A well-defined, silica-supported tungsten oxo alkyl species prepared by the surface organometallic chemistry approach displays high and sustained activity in propene metathesis. Remarkably, its catalytic performances outpace those of the parent imido derivative, underlining the importance of the oxo ligand in the design of robust catalysts.
متن کاملZ-Selective olefin metathesis reactions promoted by tungsten oxo alkylidene complexes.
Addition of LiOHMT (OHMT = O-2,6-dimesitylphenoxide) to W(O)(CH-t-Bu)(PMe(2)Ph)(2)Cl(2) led to WO(CH-t-Bu)Cl(OHMT)(PMe(2)Ph) (4). Subsequent addition of Li(2,5-Me(2)C(4)H(2)N) to 4 yielded yellow W(O)(CH-t-Bu)(OHMT)(Me(2)Pyr)(PMe(2)Ph) (5). Compound 5 is a highly effective catalyst for the Z-selective coupling of selected terminal olefins (at 0.2% loading) to give product in >75% yield with >99...
متن کاملA well-defined silica-supported dinuclear tungsten(III) amido species: synthesis, characterization and reactivity.
Grafting of [W(2)(NMe(2))(6)] onto dehydroxylated silica affords the well-defined surface species [([triple bond, length as m-dash]Si-O)W(2)(NMe(2))(5)], characterized by elemental analysis, and infrared, Raman and NMR spectroscopies, and the catalytic reactivity of this supported tungsten(III) d(3)-d(3) dimer and of its alkoxide derivatives towards alkynes has been probed.
متن کاملFundamental studies of tungsten alkylidene imido monoalkoxidepyrrolide complexes.
Two diastereomers of the monoalkoxidepyrrolide (MAP) species, W(NAr)(CH(2))(Me(2)Pyr)(OR*) (1; Ar = 2,6-diisopropylphenyl, Me(2)Pyr = 2,5-dimethylpyrrolide, OR* = (R)-3,3'-dibromo-2'-(tert-butyldimethylsilyloxy)-5,5',6,6',7,7',8,8'-octahydro-1,1'-binaphthyl-2-olate), were generated through addition of R*OH to W(NAr)(CH(2))(Me(2)Pyr)(2). The unsubstituted tungstacyclobutane species, W(NAr)(C(3)H...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Organometallics
سال: 2006
ISSN: 0276-7333,1520-6041
DOI: 10.1021/om060279d