Journal article
Multiple metal-carbon bonds. 19. How niobium and tantalum complexes of the type M(CHCMe3)(PR3)2Cl3 can be modified to give olefin metathesis catalysts
Journal of the American Chemical Society, Vol.103(6), pp.1440-1447
03/01/1981
DOI: 10.1021/ja00396a025
Abstract
Complexes of the type M(CHR)L2X3 ( M= Nb or Ta, R = CMe3 or Ph, L = a tertiary phosphine, X = Cl or Br) react with terminal olefins to give the organic products of β-hydride rearrangement of the four possible intermediate metallacyclobutane complexes. We see no metathesis products or cyclopropanes. When L = THF or py, the complex reacts with ethylene to give ~10% metathesis product, with 1-butene to give ~50% metathesis products, and with cis-2-pentene to give exclusively metathesis products. Ta(CHCMe3)(THF)2Cl3 is a short-lived metathesis catalyst for cis-2-pentene. Complexes of the type M(CHCMe3)(OCMe3)2Cl(PMe3) react with terminal and internal olefins to give only metathesis products and are longer lived (ca. 35 turnovers) metathesis catalysts for cis-2-pentene. The major chain termination steps in metathesis of a terminal olefin are decomposition (probably intermolecular) of intermediate methylene complexes and rearrangement of intermediate metallacyclobutane complexes. The major chain termination step in metathesis of cis-2-pentene is rearrangement of an alkylidene ligand in an intermediate alkylidene complex to an olefin. © 1981, American Chemical Society. All rights reserved.
Details
- Title: Subtitle
- Multiple metal-carbon bonds. 19. How niobium and tantalum complexes of the type M(CHCMe3)(PR3)2Cl3 can be modified to give olefin metathesis catalysts
- Creators
- S. M RocklageJ. D FellmannG. A RupprechtL. W MesserleR. R Schrock
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.103(6), pp.1440-1447
- Publisher
- American Chemical Society
- DOI
- 10.1021/ja00396a025
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Language
- English
- Date published
- 03/01/1981
- Academic Unit
- Chemistry; Radiology
- Record Identifier
- 9984216587302771
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