The reactions of [Fe2(cp)2(CO)2(μ-CO)(μ-CSMe)]CF 3SO3 (1; cp = η-C5H5) with a variety of carbon nucleophiles result in C-C bond formation at different sites of the molecule, (allyl)-MgCl (allyl = C3H5) undergoes cp addition to form [Fe2(cp)(η4-C5H5-allyl)(CO) 2(μ-CO)(μ-CSMe)] (2) and the alkylidene complex [Fe2(cp)(η-C5H4-allyl) (CO)2(μ-CO){μ-C(SMe)H}] (3), derived from cp to μ-C hydrogen migration. Li2Cu(CN)R2 adds at the μ-C atom to yield [Fe2(cp)2(CO)2(μ-CO){μ-C(SMe)R}] (R = Ph, 4; R = Me, 8), [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)R}] (R = Ph, 5; R = Me, 9), and [Fe2(cp)2(CO)(μ-CO){μ-C(ηl2-Ph)Ph}] (6) or the vinylidene derivative [Fe2(cp)2(CO)(μ-CO)(μ-C=CH2)] (10) in the case of phenyl or methyl organocuprate reagents, respectively. The latter complexes are the result of C-SMe bond breaking occurring, through different reaction paths, in 4 and 8. Likewise, the formation of [Fe2-(cp)2(CO)(μ-CO){μ-C=C(CN)2}] (11) from 1 and NaCH(CN)2 occurs via a direct addition at the μ-C carbon followed by HSMe elimination. The nucleophilic attack at the terminal CO in 1 is achieved with LiC≡CPh, which forms two new C-C bonds in the alkylidene complex [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)C(O)CCPh}] (12) after C(O)CCPh migration from Fe to the bridging carbene carbon. The analogous [FeFe(cp)2(CO)(μ-CO)(μ-C(SMe)C(O)(2-th)}] (13; 2-th = 2-C4H3S) and [Fe2(cp)(η4-C5H5-(2-th)(CO) 2(μ-CO)(μ-CSMe)] (14) are obtained from 1 and Lith via addition at the CO and cp groups, respectively. The relevance of these reactions is discussed in terms of selective C-C bond formation that, if it occurs at the cp or CO terminal ligands, favors the hydrogen migration (e.g. formation of 3) or the carbyne-carbonyl migratory coupling (e.g. formation of 12 and 13), respectively. The X-ray structures of [Fe2-(cp)2(CO)(μ-CO){μ-C(η2-Ph)Ph}] (6) and [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)C(O)(2-th)}] (13) have revealed the peculiarity of the Ph and SMe group coordination to the iron. Their structural features are discussed in comparison with those of analogous complexes. © 1997 American Chemical Society.
Bordoni S., Busetto L., Camiletti C., Zanotti V., Albano V.G., Monari M., et al. (1997). Selective formation of one or two C-C bonds promoted by carbanion addition to [Fe2(cp)2(CO)2(μ-CO)(μ-CSMe)]+. ORGANOMETALLICS, 16(6), 1224-1232 [10.1021/om9609168].
Selective formation of one or two C-C bonds promoted by carbanion addition to [Fe2(cp)2(CO)2(μ-CO)(μ-CSMe)]+
Bordoni S.;Monari M.;
1997
Abstract
The reactions of [Fe2(cp)2(CO)2(μ-CO)(μ-CSMe)]CF 3SO3 (1; cp = η-C5H5) with a variety of carbon nucleophiles result in C-C bond formation at different sites of the molecule, (allyl)-MgCl (allyl = C3H5) undergoes cp addition to form [Fe2(cp)(η4-C5H5-allyl)(CO) 2(μ-CO)(μ-CSMe)] (2) and the alkylidene complex [Fe2(cp)(η-C5H4-allyl) (CO)2(μ-CO){μ-C(SMe)H}] (3), derived from cp to μ-C hydrogen migration. Li2Cu(CN)R2 adds at the μ-C atom to yield [Fe2(cp)2(CO)2(μ-CO){μ-C(SMe)R}] (R = Ph, 4; R = Me, 8), [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)R}] (R = Ph, 5; R = Me, 9), and [Fe2(cp)2(CO)(μ-CO){μ-C(ηl2-Ph)Ph}] (6) or the vinylidene derivative [Fe2(cp)2(CO)(μ-CO)(μ-C=CH2)] (10) in the case of phenyl or methyl organocuprate reagents, respectively. The latter complexes are the result of C-SMe bond breaking occurring, through different reaction paths, in 4 and 8. Likewise, the formation of [Fe2-(cp)2(CO)(μ-CO){μ-C=C(CN)2}] (11) from 1 and NaCH(CN)2 occurs via a direct addition at the μ-C carbon followed by HSMe elimination. The nucleophilic attack at the terminal CO in 1 is achieved with LiC≡CPh, which forms two new C-C bonds in the alkylidene complex [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)C(O)CCPh}] (12) after C(O)CCPh migration from Fe to the bridging carbene carbon. The analogous [FeFe(cp)2(CO)(μ-CO)(μ-C(SMe)C(O)(2-th)}] (13; 2-th = 2-C4H3S) and [Fe2(cp)(η4-C5H5-(2-th)(CO) 2(μ-CO)(μ-CSMe)] (14) are obtained from 1 and Lith via addition at the CO and cp groups, respectively. The relevance of these reactions is discussed in terms of selective C-C bond formation that, if it occurs at the cp or CO terminal ligands, favors the hydrogen migration (e.g. formation of 3) or the carbyne-carbonyl migratory coupling (e.g. formation of 12 and 13), respectively. The X-ray structures of [Fe2-(cp)2(CO)(μ-CO){μ-C(η2-Ph)Ph}] (6) and [FeFe(cp)2(CO)(μ-CO){μ-C(SMe)C(O)(2-th)}] (13) have revealed the peculiarity of the Ph and SMe group coordination to the iron. Their structural features are discussed in comparison with those of analogous complexes. © 1997 American Chemical Society.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
