| Popis: |
The η 1 -α-alkoxyethyl complexes CpFe(CO)L[CH(OCH 3 )CH 3 ] (IIa, L = CO; IIb, L = PPh 3 ; IIc, L = P(OPh) 3 ) have been prepared by the LiHBEt 3 reduction of the requisite alkoxycarbene compounds CpFe(CO)L[C(OCH 3 )CH 3 ] + PF 6 − . Treatment of IIb and IIc with acid or Ph 3 C + selectively affords the ethylidene salts CpFe(CO)L(CHCH 3 ) + (Ib, L = PPh 3 ; Ic, L = P(OPh) 3 ), which thermally isomerize below 25° C to the η 2 -ethylene complexes CpFe(CO)L(CH 2 CH 2 ) + . Ib and Ic, also produced by protonation of the vinyl complexes CpFe(CO)L(CHCH 2 ), were trapped by PPh 3 adduct formation (L = PPh 3 , P(OPh) 3 ), by deprotonation to its vinyl complex (L = P(OPh) 3 ), and by LiHBEt 3 reduction (L = P(OPh) 3 ). Treatment of IIa with acid or Ph 3 C + (or CpFe(CO) 2 CH&.dbnd;CH 2 with acid) gives varying mixtures of CpFe(CO) 2 (CHCH 2 ) + and the β-metallocarbonium ion complex [CpFe(CO) 2 CH 2 CHCH(CH 3 )Fe(CO) 2 Cp] + , both necessitating intermediacy of Ia. |
