α-CH Bond Activation of Coordinated Et₂O via Reaction of PR₃ (R = Ph, Cy) with the Cationic Complex [C₅Me₅W(CO)₃(OEt₂)]⁺

Reaction of C 5 Me 5 W(CO) 3 CH 3 ( 2 ) with [Et 2 O) 2 H] + BAr 4 - (Ar = 3,5-bis(trifluoromethyl)phenyl) produced the new cationic complex [C 5 Me 5 W(CO) 3 (OEt 2 )] + BAr 4 - ( 1 ) in 82% isolated yield. The complex 1 readily undergoes ligand substitution reactions with neutral donor ligands to give the complexes [C 5 Me 5 W(CO) 3 (L)] + BAr 4 - (L = CH 3 CN ( 3 ), MeOH ( 4 ), H 2 O ( 5 )). In contrast, reaction of 1 with tertiary phosphines PR 3 (R = Ph, Cy) produced C 5 Me 5 W(CO) 3 H ( 6 ) and the new phosphonium salts EtOCH(Me)PR 3 + BAr 4 - (R = Ph ( 7 ), Cy ( 8 )), where the α-CH of Et 2 O has been selectively displaced by phosphines.