The stereochemistry of electrophilic addition to tricarbonyldieneiron complexes

Greaves, E. O.; Knox, G. R.; Pauson, P. L.; Tomá, Štefan; Sim, G. A.; Woodhouse, D. I.

doi:10.1039/c39740000257

Cited by 36 publications

(6 citation statements)

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“…Figures 1 and 2 4)) = 2.010 (2) Á. Because the central allylic carbon atom C(4) lies in a crystallographic mirror plane, the two allylic C-C bonds are equal, 1.409 (2) Á, and in agreement with values recently reported for the structures of |[t,3-(H3C)C2H3-(CHCH3C(0)CH3)]Fe(CO)3j+ (1.384 (15), 1.404 (16) A), 15 [(C2H5)2B(C3N2H3)2](t,3-C3H5)(C3N2H4)(CO)2Mo (1.387 (6), 1.412 (6) A),16 and [(C2H5)2B(C3N2H3)2] [t,3-CH2C-(C6H5)CH2](CO)2Mo (1.393 (10), 1.411 (10) A).17…”

Section: Description Of the Structuressupporting

confidence: 90%

Syntheses and crystal structures at -35.degree.C of bis(.eta.3-2-allyl)-1,2-ethanobis(tricarbonylcobalt) and bis(.eta.3-2-allyl)-1,3-propanonobis((trimethyl phosphite)dicarbonylcobalt)

Cann¹,

Riley²,

Davis³

et al. 1978

Inorg. Chem.

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The two T73-allyl complexes {(CO)3Co[(CH2)2CCH2]j2 and |(CO)3Co[(CH2)2CCH2](2CO have been prepared by reaction of (chloromethyl)allyl chloride and NaCo(CO)4 in refluxing THF. Both species are formed during this reaction and may be converted to the trimethyl phosphite derivatives by replacement of one CO ligand per Co atom. The structures of |(CO)3Co[(CH2)2CCH2]|2 and j[(CH30)3P](CO)2Co[(CH2)2CCH2]j2CO have been determined by single-crystal x-ray diffraction techniques with three-dimensional data gathered at -35 °C by counter methods. Bulky yellow crystals of ((CO)3Co[(CH2)2CCH2])2 form in monoclinic space group C2/m, with unit cell constants (at -35 °C) a = 11.570 (3) Á, b = 10.910 (2) Á, c = 6.568 (1) Á, and ß = 99.95 (1)°. The calculated density of 1.583 g cm™3, assuming two molecules of {(CO)3Co[(CH2)2CCH2]}2 per unit cell, agrees with the measured value of 1.57 g cm™3. |[(CH30)3P](CO)2Co[(C-H2)2CCH2]}2CO crystallizes as thin yellow prisms in orthorhombic space group P2{2{2, with unit cell constants (at -35 °C) a = 19.688 (4), b = 20.843 (10), and c = 6.532 (2) Á. The calculated density of 1.528 g cm™3 for four molecules of phosphite complex per unit cell agrees with the measured value of 1.50 g cm™3. Full-matrix least-squares refinements of the structures have converged with R indices (on |E|) of 0.021 and 0.062 for the j(CO)3Co[(CH2)2CCH2]j2 and j[(CH30)3P](CO)2Co[(CH2)2CCH2]j2CO complexes, respectively, using the 1168 and 2134 symmetry-independent reflections with /" > 2.0 (/0). Molecules of ¡(CO)3Co[(CH2)2CCH2]|2 possess rigorous Cy, symmetry and display the significant differences in Co-C(carbonyl) distances which have previously been attributed to the nature of the Co-t;3-allyl interaction. Although molecules of |[(CH30)3P](CO)2Co[(CH2)2CCH2]|2CO have no rigorous crystallographic symmetry, they do exhibit approximate-C2 symmetry. In addition to the Co-C(carbonyl) bond asymmetry noted in |(CO)3Co[(CH2)2CCH2]|2, the substitution of P(OCH3)3 for CO has produced differences in the Co-C(allyl, terminal) bond lengths of |[(CH30)3-P] (CO)2Co[(CH2)2CCH2] |2CO.

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Section: Description Of the Structuressupporting

confidence: 90%

Syntheses and crystal structures at -35.degree.C of bis(.eta.3-2-allyl)-1,2-ethanobis(tricarbonylcobalt) and bis(.eta.3-2-allyl)-1,3-propanonobis((trimethyl phosphite)dicarbonylcobalt)

Cann¹,

Riley²,

Davis³

et al. 1978

Inorg. Chem.

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“…Since the time of the work by Hallam and Pauson, the chemistry of acyclic and cyclic (1,3-diene)iron tricarbonyl complexes has become an active research area and some interesting reactions of (butadiene)iron tricarbonyl itself and of many new substituted (butadiene)iron tricarbonyl complexes have been reported. For instance, (butadiene)iron tricarbonyl reacted with acetic anhydride in CH 2 Cl 2 in the presence of AlCl 3 to give the 1-acetyl derivative 11a. Competition studies 11a showed (C 4 H 6 )Fe(CO) 3 to have a Friedel−Crafts reactivity similar to that of ferrocene (which Woodward and Rosenblum had shown to be a superelectrophile).…”

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confidence: 99%

“…Competition studies 11a showed (C 4 H 6 )Fe(CO) 3 to have a Friedel−Crafts reactivity similar to that of ferrocene (which Woodward and Rosenblum had shown to be a superelectrophile). Later work showed that Friedel−Crafts acylation of (butadiene)iron tricarbonyl proceeds via a substituted allyliron tricarbonyl cation intermediate in which the acyl oxygen atom is coordinated to the iron atom 11b…”

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confidence: 99%

(Cyclobutadiene)iron TricarbonylA Case of Theory before Experiment

Seyferth

2002

Organometallics

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“…This type of approach has not previously been used in the case of cyclohexadiene ligands and Fe(CO) 3 . The 4-methoxy-1-cyclohexa-1,3-dieneacetic acid derivative was chosen on the basis of the previous proposed coordination of the carbonyl group to Fe(CO) n during complexation . Furthermore this complex has been shown to be an important building block for the iron-mediated diastereoselective synthesis of spirocycles …”

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confidence: 99%

Asymmetric Tricarbonyliron Complexation of Cyclohexadiene Directed by Chiral Ester and Amide Auxiliaries

1996

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Coupling of (+)-menthol, (+)-phenylethylamine and (-)-proline methyl ester with 4-methoxy-1cyclohexa-2,4-dieneacetic acid gave the chiral ester 1 and amides 2 and 3, respectively, which were then isomerized into the 1,3-dienes. The diastereoselection induced by the chiral ester and amide auxiliaries during complexation with nonacarbonyliron was quite encouraging. The diastereomeric ratios of the ester-and amide-Fe(CO) 3 complexes formed were determined directly from the 1 H NMR integration of observable diastereotopic chemical shifts.

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The stereochemistry of electrophilic addition to tricarbonyldieneiron complexes

Cited by 36 publications

References 0 publications

Syntheses and crystal structures at -35.degree.C of bis(.eta.3-2-allyl)-1,2-ethanobis(tricarbonylcobalt) and bis(.eta.3-2-allyl)-1,3-propanonobis((trimethyl phosphite)dicarbonylcobalt)

Syntheses and crystal structures at -35.degree.C of bis(.eta.3-2-allyl)-1,2-ethanobis(tricarbonylcobalt) and bis(.eta.3-2-allyl)-1,3-propanonobis((trimethyl phosphite)dicarbonylcobalt)

(Cyclobutadiene)iron TricarbonylA Case of Theory before Experiment

Asymmetric Tricarbonyliron Complexation of Cyclohexadiene Directed by Chiral Ester and Amide Auxiliaries

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