Reactivity of [MCl(η³-allyl)(1,10-phenanthroline)(CO)₂] (M = Mo, W) Complexes toward Enolate Anions

The reactions of the complexes [MCl(η 3 -C 3 H 4 -R)(CO) 2 (phen)] ( 1a − c; M = Mo, W) with KCH 2 C(O)Ar afford the O-bound enolato complexes [M(η 3 -C 3 H 4 -R){OC( CH 2 )Ar}(CO) 2 (phen)] ( 2a − d ). On the other hand, the reactions of molybdenum chloro complexes with KCH 2 CN yield the complexes [Mo(η 3 -C 3 H 4 -R)(CH 2 CN)(CO) 2 (phen)] ( 3a, b ), in which the nitrile enolate ligand is C-bound. In addition to the spectroscopic characterization by means of IR and NMR, the structures of [Mo(η 3 -C 3 H 5 ){OC( CH 2 )(naphthyl}(CO) 2 (phen)] ( 2c ) and [Mo(η 3 -C 3 H 4 -Me-2)(CH 2 CN)(CO) 2 (phen)] ( 3a ) were determined by X-ray diffraction.