Characterization C4H6Fe(CO)3.SO2.BF3, the product of an arrested Friedel-Crafts sulfination of butadieneiron tricarbonyl

Wormald, John; Young, David; Kaesz, H. D.

doi:10.1021/ja01053a059

Cited by 18 publications

(3 citation statements)

References 2 publications

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“…Despite the similarity of O and C phase‐shifts, attempts to fit an O shell at 2.09 Å together with a C shell at 2.00 Å result in significantly increased refinement ( R ) factors and unacceptable Debye–Waller factors for these two shells. Although the quality of the data certainly limits the precision of this distant shell, the FeO distance is similar to those observed in iron(III) acetylacetonate (1.99 Å)30 and C 4 H 6 Fe(CO) 3 ⋅SO 2 ⋅BF 2 (2.00 Å) 31. The FeC distance lies between those of ferrocene (2.06 Å) and Fe–alkene (2.14–2.16 Å),32 and is close to that of tricarbonyl tetraphenylacetylcyclobutadieneiron (2.08 Å) 33.…”

Section: Resultssupporting

confidence: 74%

Development of a Flexible Strategy towards FR900482 and the Mitomycins

Trost

O'Boyle

Torres

et al. 2011

Chemistry A European J

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FR900482 and the mitomycins are two intriguing classes of alkaloid natural products that have analogous biological mechanisms and obvious structural similarity. Both classes possess potent anti-cancer activity, a feature that has led to their investigation and implementation for the clinical treatment of human cancer. Given the structural similarity between these natural products, we envisioned a common synthetic strategy by which both classes could be targeted through assembling the mitomycin skeleton prior to further oxidative functionalization. Realization of this strategy with respect to FR900482 was accomplished through the synthesis of 7-epi-FR900482, which displayed equal potency relative to the natural product against two human cancer cell lines. With the challenging goal of a synthesis of either mitomycin or FR900482 in mind, several methodologies where explored. While not all of these methods ultimately proved useful for our synthetic goal, a number of them led to intriguing findings that provide a more complete understanding of several methodologies. In particular, amination via π-allyl palladium complexes for the synthesis of tetrahydroquinolines, 8-membered heterocycle formation via carbonylative lactamization, and amination through late-stage C-H insertion via rhodium catalysis all featured prominently in our synthetic studies.

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Section: Resultssupporting

confidence: 74%

Development of a Flexible Strategy towards FR900482 and the Mitomycins

Trost

O'Boyle

Torres

et al. 2011

Chemistry A European J

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“…Although the quality of the data certainly limits the precision of this distant shell, the FeÀO distance is similar to those observed in ironA C H T U N G T R E N N U N G (III) acetylacetonate (1.99 ) [30] and C 4 H 6 Fe(CO) 3 ·SO 2 ·BF 2 (2.00 ). [31] The Fe À C distance lies between those of ferrocene (2.06 ) and Fealkene (2.14-2.16 ), [32] and is close to that of tricarbonyl tetraphenylacetylcyclobutadieneiron (2.08 ). [33] The 2 eV, which is clearly due to the strong interaction of iron with the zeolite support.…”

Section: Tpd-ms and Tpr-msmentioning

confidence: 79%

A Mononuclear Cyclopentadiene–Iron Complex Grafted in the Supercages of HY Zeolite: Synthesis, Structure, and Reactivity

Long

Wang

Zhang

et al. 2007

Chemistry A European J

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The reaction of ferrocene with the acidic hydroxy groups in the supercages of zeolite HY dehydrated at 673 K and the reactivity of the resultant surface species towards CO and O(2) were investigated by temperature-programmed decomposition (TPD) and reduction (TPR) and IR, X-ray absorption fine structure analysis (XAFS), and X-ray photoelectron (XP) spectroscopy. In situ FTIR, TPD, TPR, and chemical analysis reveal that the Cp(2)Fe molecule adsorbed on the zeolite surface loses one cyclopentadienyl group under vacuum at 423 K, which leads to the formation of a well-defined mononuclear surface Fe-C(5)H(6) complex grafted to two acidic sites and one ([triple bond]Si-O-Si[triple bond]) unit, as confirmed by the lack of Fe-Fe contributions in the EXAFS spectra. Each iron atom is coordinated, on average, to three oxygen atoms of the zeolite surface with a Fe--O distance of 2.00 A and to five carbon atoms with a Fe--C distance of 2.09 A. IR spectra indicate that the cyclopentadiene-iron species grafted on the surface of the zeolite is quite stable in vacuo or under an inert or hydrogen atmosphere below 423 K, and is also relatively stable under oxygen at room temperature. However, the cyclopentadiene ligand readily reacts with CO to form a compound containing carbonyl at 323 K, and even at room temperature. The single carbonyl band in the IR spectra provides evidence for the nearly uniform formation of a cyclopentadiene-iron species on the surface of the zeolite.

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“…17 In the presence of BF3, S02 undergoes an addition reaction with r;4-C4H4Fe(CO)3 to afford (t,3-CH2CHCH-CH2)fe(CO)3[ÓÍ(OBF3)],19 which was characterized by X-ray crystallography. 19•20 Antimony(V) fluoride behaves similarly to BF3. There is no observable reaction in the absence of the Lewis acid.…”

Section: Introductionmentioning

confidence: 99%

Lewis acid mediated reactions of organotransition metal complexes. A marked promotion of the sulfur dioxide insertion in alkyl(.eta.5-cyclopentadienyl)tricarbonyltungsten(II) by boron(III) and antimony(V) fluorides

Severson¹,

Wojcicki²

1979

J. Am. Chem. Soc.

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The insertion of SO2 into the W-R bond of q5-C5H5W(C0)3R (R = CH3, la; R = CH2C6H5, lb) in liquid SO2 is markedly promoted by the Lewis acids BF3 and SbF5. Thus, at -26 OC the reaction of l a with S02-BF3 appears to be at least 20 000 times faster than the reaction of l a with SO2 alone. The promoted reaction proceeds to the corresponding Lewis acid stabilized 0-sulfinato complexes, q5-C5H5W(CO)3[OS(OBF3 or OSbF5)RI (BF3: R = CH3, 3a; R = CH2CsH5, 3b. SbF5: R = CH3,4a; R = CHf&H5,4b), which were isolated and characterized by a combination of elemental analysis and infrared and IH NMR spectroscopy; by contrast, the insertion of SO2 alone continues to the S-sulfinato complexes, q5-C~H5W-(CO)3S(O)*R (R = CH3, 2a; R = CH2CsH5, 2b). Treatment of 3a with "3, CsH5NH2, or other Lewis bases affords 2a in good yield, whereas storage of 3a in benzene--pentane furnishes some isomeric q5-C5H5W(CO)3[S(0)(OBF3)CH3] (5a). Complex 5a also results upon treatment of 2a with BF3 in toluene at 25 OC or in SO2 at -16 "C; this reaction may be reversed by the application of vacuum. Other similar 1:l adducts of 2a or 2b and BF3 or SbF5 (or FSSbOSO) were prepared by direct reaction of the appropriate components in SO2 solution. The promotion of the reaction of the tungsten-alkyl complexes with SO2 by BF3 or SbFS is thought to derive from a stronger electrophilic character of the Lewis acid802 adduct than of the SO2 alone. Mechanistic aspects of the promoted and unpromoted insertion of SO2 are discussed, and possible extensions of this approach to other reactions at transition metal-carbon u bonds are considered.

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Characterization C4H6Fe(CO)3.SO2.BF3, the product of an arrested Friedel-Crafts sulfination of butadieneiron tricarbonyl

Cited by 18 publications

References 2 publications

Development of a Flexible Strategy towards FR900482 and the Mitomycins

Development of a Flexible Strategy towards FR900482 and the Mitomycins

A Mononuclear Cyclopentadiene–Iron Complex Grafted in the Supercages of HY Zeolite: Synthesis, Structure, and Reactivity

Lewis acid mediated reactions of organotransition metal complexes. A marked promotion of the sulfur dioxide insertion in alkyl(.eta.5-cyclopentadienyl)tricarbonyltungsten(II) by boron(III) and antimony(V) fluorides

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