178115-84-9Relevant academic research and scientific papers
Molybdenum and tungsten cyclopentadienone complexes. 2. Regio- and stereospecific nucleophilic addition reactions
Slugovc, Christian,Mauthner, Klaus,Mereiter, Kurt,Schmid, Roland,Kirchner, Karl
, p. 2954 - 2960 (2008/10/08)
The cationic complexes [M(η4-C5H4O)(CO)2(HB(pz) 3)]PF6 (1a, 2) and [M(η4-C5H4O)(CO) 2-(bipy)Br]PF6 (3, 4) (M = Mo, W) have been shown to react with a wide variety of carbon, nitrogen, phosphorus, and sulfur nucleophiles in a regio- and stereoselective fashion to afford functionalized η3-cyclopentenoyl complexes in high yields. Single-crystal studies have been carried out for [Mo(η3-C5H4OPBu3 n)(CO)2(HB(pz)3)]PF6 (5a) and [W(η3-C5H4O-PMe 3)(bipy)-(CO)2]PF6 (8a). The reaction of [Mo(η4-C5H3O-2-Me)(CO) 2(HB(pz)3)]PF6 (1b) with strong bases like MeLi, NHEt2, or pyridine results in the clean deprotonation of the methyl group to afford Mo(η3-C5H3OCH2)(CO) 2(HB(Pz)3) (9b). This process is reversible, and 9b is quantitatively converted to 1b on treatment with strong acids such as CF3SO3H or CF3-COOH. 9b has been characterized by X-ray crystallography. Liberation of cyclopentenone from Mo(η3-C5H5O)(CO)2(HB(pz) 3) was attempted. Unfortunately, the various methods of demetalation well established for the C5H5 analog systems proved to be unsuccessful.
