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Molybdenum Imido Alkylidene Metathesis Catalysts That Contain Electron-Withdrawing Biphenolates or Binaphtholates

2007; American Chemical Society; Volume: 26; Issue: 10 Linguagem: Inglês

10.1021/om061134+

1520-6041

Rojendra Singh, Constantin Czekelius, Richard R. Schrock, Péter Müller, Amir H. Hoveyda,

Chemical Synthesis and Analysis

We have prepared new Mo(NR)(CHCMe(2)Ph)(diolate) complexes (R = 2,6-i-Pr(2)C(6)H(3), 2,6-Me(2)C(6)H(3), 1-Adamantyl, or 2-CF(3)C(6)H(4)) that contain relatively electron-withdrawing binaphtholate (3,3'-bis-(9-anthracenyl), 3,3'-bispentafluorophenyl, or 3,3'-bis(3,5-bis(trifluoromethyl)phenyl) or biphenolate (3,3'-di-tert-butyl-5,5'-bistrifluoromethyl-6,6'-dimethyl-1,1'-biphenyl-2,2'-diolate) ligands. We also have prepared new monomeric Mo(NR)(CHCMe(2)Ph)(2,5-dimethylpyrrolide)(2) complexes and have treated them with biphenols or binaphthols in order to prepare several Mo(NR)(CHCMe(2)Ph)(diolate) species. In one case the new Mo(NR)(CHCMe(2)Ph)(diolate) complexes could be prepared only through reaction of a binaphthol [3,3'-bis(pentafluorophenyl)binaphthol] with a bis(2,5-dimethylpyrrolide) complex. The pyrrolide approach can be employed either to isolate catalysts on a preparative scale or to generate catalysts in situ. Several simple preliminary ring-closing metathesis reactions show that the new complexes are catalytically competent.