TY - JOUR
T1 - Interaction of Alkylaluminum Reagents with Organotransition-Metal Arene Complexes
T2 - Net Addition of Alkide, Haloalkide, and Dichloromethide to [(arene)2Fe]2+ Cations
AU - Atwood, Jerry L.
AU - Christie, Sean D.
AU - Clerk, Michael D.
AU - Osmond, David A.
AU - Sturge, K. Craig
AU - Zaworotko, Michael J.
PY - 1992/1/1
Y1 - 1992/1/1
N2 - AlEt3 reacts with the hexafluorophosphate salts of Ar2Fe2+ cations (Ar = arene = benzene (1a), p-xylene (1b), mesitylene (1c), pentamethylbenzene (1d), hexamethylbenzene (1e)) in dichloromethane or 1,2-dichloroethane to afford ChArFe+ (Ch = cyclohexadienyl) cations. The major products, the hexafluorophosphate salts of 2a-e, result from net Et- addition to a single arene ring. The corresponding reactions with AlMe3 in CH2X2 (X = Cl, Br) are more complex and afford characterizable products for 1c,e only. The unexpected major products of these reactions are the hexafluorophosphate salts of the [(6-CH2XCh) ArFe]+ monocations 3c,e (X = Cl) and 4c,e (X = Br), derived from net addition of CH2X, rather than the expected methide addition products, 5a-e. 1c reacts with [N(CH2CH2O)3Al2Me3]2 (6), a compound that contains an octahedral aluminum methyl moiety, in dichloromethane to produce yet another ChArFe+ species, (η5-exo-6-(dichloromethyl)-1,3,5-trimethylcyclohexadienyl)(η6-mesitylene)iron(II) hexafluorophosphonate (7c[PF6]), which is the result of net addition of CHCl2-. The methide addition monocationic product 5c[PF6] can be prepared in low yield from AlMe3 or 6 and 1c if benzene and 1,2-dichloroethane, respectively, are utilized as solvent. The relevance of these reactions is discussed in the general context of transition-metal activation of Ar molecules. In addition to spectroscopic characterization, several compounds were characterized by X-ray crystallography. Full crystallographic details of the CH2Cl-Ch and CHCl2-Ch cations 3c and 7c, respectively, are presented and discussed in the context of related ChFe compounds: 3c[PF6], orthorhombic, Pcab, with a = 15.2496 (9) Å,b = 15.5537 (10) Å, c = 17.5146 (16) Å, Z = 8, R = 0.059, Rw = 0.058 for 2506 independent, observed (I > 2.5σ(I)), and absorption-corrected reflections; 7c[PF6]·(CH3)2CO, monoclinic, P21/c, with a = 18.762 (3) Å, b = 8.758 (2) Å, c = 17.104 (3) Å, β = 113.40 (2)°, Z = 4, R = 0.049, Rw = 0.055 for 2051 independent, observed (I > 2.5σ(I)), and absorption-corrected reflections.
AB - AlEt3 reacts with the hexafluorophosphate salts of Ar2Fe2+ cations (Ar = arene = benzene (1a), p-xylene (1b), mesitylene (1c), pentamethylbenzene (1d), hexamethylbenzene (1e)) in dichloromethane or 1,2-dichloroethane to afford ChArFe+ (Ch = cyclohexadienyl) cations. The major products, the hexafluorophosphate salts of 2a-e, result from net Et- addition to a single arene ring. The corresponding reactions with AlMe3 in CH2X2 (X = Cl, Br) are more complex and afford characterizable products for 1c,e only. The unexpected major products of these reactions are the hexafluorophosphate salts of the [(6-CH2XCh) ArFe]+ monocations 3c,e (X = Cl) and 4c,e (X = Br), derived from net addition of CH2X, rather than the expected methide addition products, 5a-e. 1c reacts with [N(CH2CH2O)3Al2Me3]2 (6), a compound that contains an octahedral aluminum methyl moiety, in dichloromethane to produce yet another ChArFe+ species, (η5-exo-6-(dichloromethyl)-1,3,5-trimethylcyclohexadienyl)(η6-mesitylene)iron(II) hexafluorophosphonate (7c[PF6]), which is the result of net addition of CHCl2-. The methide addition monocationic product 5c[PF6] can be prepared in low yield from AlMe3 or 6 and 1c if benzene and 1,2-dichloroethane, respectively, are utilized as solvent. The relevance of these reactions is discussed in the general context of transition-metal activation of Ar molecules. In addition to spectroscopic characterization, several compounds were characterized by X-ray crystallography. Full crystallographic details of the CH2Cl-Ch and CHCl2-Ch cations 3c and 7c, respectively, are presented and discussed in the context of related ChFe compounds: 3c[PF6], orthorhombic, Pcab, with a = 15.2496 (9) Å,b = 15.5537 (10) Å, c = 17.5146 (16) Å, Z = 8, R = 0.059, Rw = 0.058 for 2506 independent, observed (I > 2.5σ(I)), and absorption-corrected reflections; 7c[PF6]·(CH3)2CO, monoclinic, P21/c, with a = 18.762 (3) Å, b = 8.758 (2) Å, c = 17.104 (3) Å, β = 113.40 (2)°, Z = 4, R = 0.049, Rw = 0.055 for 2051 independent, observed (I > 2.5σ(I)), and absorption-corrected reflections.
UR - http://www.scopus.com/inward/record.url?scp=0010841834&partnerID=8YFLogxK
U2 - 10.1021/om00037a057
DO - 10.1021/om00037a057
M3 - Article
AN - SCOPUS:0010841834
SN - 0276-7333
VL - 11
SP - 337
EP - 344
JO - Organometallics
JF - Organometallics
IS - 1
ER -