Further studies of imido alkylidene complexes of tungsten, well-characterized olefin metathesis catalysts with controllable activity

Journal Article · Tue Jul 31 20:00:00 EDT 1990 · Organometallics; (USA)

DOI:https://doi.org/10.1021/om00158a025· OSTI ID:6379546

Schrock, R R; DePue, R T; Feldman, J; Yap, K B; Yang, D C; Davis, W M; Park, L; DiMare, M; Schofield, M; Anhaus, J ^[1]; Walborsky, E; Evitt, E ^[2]; Krueger, C; Betz, P ^[3]

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1. Massachusetts Institute of Technology, Cambridge (USA)
2. Catalytica Inc., Mountain View, CA (USA)
3. Max-Planck-Institute fuer Kohlenforschung, Ruhr (West Germany)

An alternative synthesis of W(CH-t-Bu)(NAr)(dme)Cl{sub 2} (Ar = 2,6-C{sub 6}-H{sub 3}-i-Pr{sub 2}) consists of the five steps WCl{sub 6} {yields} W(O)Cl{sub 4} {yields} W(NAr)Cl{sub 4} {yields} W(NAr)(O-t-Bu){sub 2}Cl{sub 2}(THF) {yields} W(NAr)(O-t-Bu){sub 2}(CH{sub 2}-t-Bu){sub 2} {yields} W(CH-t-Bu)(NAr)(dme)Cl{sub 2}, in which tert-butoxide protecting groups are replaced by chlorides in the last step upon addition of PCl{sub 5}. The easiest synthesis to a catalyst precursor consists of the three steps WO{sub 2}Cl{sub 2} {yields} W(NAr){sub 2}Cl{sub 2}(dme) {yields} W(NAr){sub 2}(CH{sub 2}R){sub 2} {yields} W(CHR)(NAr)(OTf){sub 2}(dme) (R = t-Bu, CMe{sub 2}Ph; OTf = OSO{sub 2}CF{sub 3}), in which an imido ligand protecting group is ultimately replaced by two triflate ligands upon addition of triflic acid in the last step. An X-ray study of W(CH-t-Bu)(NAr)(O-t-Bu){sub 2} shows it to be a pseudotetrahedral complex in which the tert-butyl group points toward the imido ligand.

• DOE Contract Number: FG05-86ER75292
• OSTI ID: 6379546
• Journal Information: Organometallics; (USA), Journal Name: Organometallics; (USA) Vol. 9:8; ISSN 0276-7333; ISSN ORGND
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CATALYSTS
COMPLEXES
CRYSTAL STRUCTURE
DATA
DATA ANALYSIS
EXPERIMENTAL DATA
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES