Electrophilic discrimination of the ambident organometallic nucleophile (.eta.3-C7H7)Fe(CO)3- in its reaction with Group 14 halides: synthesis and fluxional behavior of (.eta.3-C7H7)Fe(CO)3EPh3 (E = Sn, Pb)

Synthesis, Characterization and Reactivity of the Tricarbonyl(formylcycloheptatrienyl)iron‐Anion [(η3‐C7H6CHO)Fe(CO)3]−

“…Thus the Me 3 SiCl reaction appears to sample different reactive forms of the anion (Scheme 6). This again is different from the reactivity of the unsubstituted anion 1Fe, where Me 3 SiCl gave ring-substituted products [12].…”

Multisite Magnetization Transfer Studies of Metal Migration in (η3-C7H7)Re(CO)4, (η3-C7H7)Os(CO)3SnPh3, (η3-C7H7)Re(CO)3PMe3, (η5-C7H7)Re(CO)3, (η5-C7H7)Fe(CO)2SnPh3, (η5-C7H7)Os(CO)2SnPh3, and (η5<

“…The rate of axialaxial carbonyl exchange was found to be almost 2 orders of magnitude slower than the 1,2-metal shifts in the cycloheptatrienyl ring in 2a, and the value of the free energy of activation for axial-axial carbonyl exchange is very different from the value given in Table 2 for "ring whizzing" in this compound. Since the carbonyl ligands in 1 do not exchange and the carbonyls in 2 are not exchanged at the same rate as the 1,2-metal shift around the cycloheptatrienyl ring, the metal shifts and the carbonyl exchange must be independent processes, just as Reuvers 75 has concluded for the Fe analogue of 2. Hence we must conclude that the observed 1,2-metal shifts in compounds 1 and 2 cannot be viewed as [1,5]sigmatropic processes.…”

“…The assignments given in Figure 4 are based on intensity data, chemical shift considerations, and homonuclear decoupling experiments and are in accord with previous studies on η 3 -C 7 H 7 compounds. 75 The identification of 2s as the fac-exo arrangement, as shown in Figure 2, rather than the fac-endo one with the SnPh 3 group placed near the C 7 H 7 ring, is based on arguments presented in discussing the analogous iron compound. 75 We cannot rule out the presence of a small amount of the fac-endo symmetrical isomer since Figure 4 a Numbers in parentheses are the estimated errors in ∆G q derived from the nonlinear errors in the rate constants obtained from least squares analysis of MMT data.…”

“…75 The identification of 2s as the fac-exo arrangement, as shown in Figure 2, rather than the fac-endo one with the SnPh 3 group placed near the C 7 H 7 ring, is based on arguments presented in discussing the analogous iron compound. 75 We cannot rule out the presence of a small amount of the fac-endo symmetrical isomer since Figure 4 a Numbers in parentheses are the estimated errors in ∆G q derived from the nonlinear errors in the rate constants obtained from least squares analysis of MMT data. the ratio of their integrated intensities is approximately 3:1.…”

New chemical and stereochemical applications of organoiron complexes

“…Additional carbon-carbon bond formations are: synthesis of [Fe 2 (CO) 6 (η-C(OR)H)(η-CR′ = CR′H)] − anions (R = Me, Et; R′ = Ph, H) (at a dinculear iron center) [ 1027 ], synthesis of a new tert -butylnitroso complex [CpFe(CO)(PPh 3 )N(O) tert -Bu] + (Cp=η 5 -C 5 H 5 ) [ 1028 ], synthesis of a new bis(phosphino)methanideiron complex Cp(CO)Fe(Ph 2 PCH PPh 2 ) [ 1029 ]; also preparation of derivatives from doubly-bridged diiron complexes of the type [(η-η 2 -ROC(1)S)Fe 2 (CO) 6 (η-SMe)] (via ligand-exchange reactions) [ 1030 ], synthesis of cycloheptatriene complexes (η 3 -C 7 H 7 )Fe(CO) 3 EPh 3 (E = Sn, Pb) [ 1031 ], and synthesis of benzophenones through carbonylation of aryl iodides catalyzed by the Fe(CO) 5 -CO 2 (CO) 8 system [ 1032 ].…”