SYNTHESIS AND REACTIVITY OF BIS(ETHYLENE)-PHOSPHITE COMPLEXES OF MOLYBDENUM(0)

The compounds trans-Mo(C2H4)(2){P(OR)(3)}(4) (R = Mer 1a; Et, 1b) were prepared by the direct reduction of MoCl4(THF)(2) with Na-Hg, under e thylene, in the presence of the appropriate phosphite. Reaction of 1 w ith CO yields trans,trans-Mo(C2H4)(2)(Co)(2){P(OR)(3)}(2) (R = Me, 2a; Et, 2b), while the interaction of 1a with (CNPr)-Pr-i affords the com plex ns,trans-Mo(C2H4)(2)((CNPr)-Pr-i)(2){P(OMe)(3)}(2) (3). The react ion of compounds 1a and 1b with CO2 provides hydride acrylate derivati ves of composition MoH(OOCCH=CH2){P(OR)(3)}(4) (R = Me, 4a; Et, 4b), w hich are formed through a coupling of the ethylene ligand and carbon d ioxide at the molybdenum center. The analogous reaction of 1b with CS2 produces instead Mo(C2S4)(C2H4){P(OEt)(3)}(3) (5) containing ahead-to -tail carbon disulfide metallacycle dimer. (C) 1998 Elsevier Science S .A. All rights reserved.