Stereochemistry of the oxidative addition of an epoxide to platinum(II): relevance to catalytic reactions of epoxides

Aye, Khin Than; Gelmini, Lucio; Payne, Nicholas C.; Vittal, Jagadese J.; Puddephatt, Richard J.

doi:10.1021/ja00162a082

Cited by 39 publications

(21 citation statements)

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“…Note that both two transition states TS(3/4a) and TS(14/15) lie below the initial reactants about À14.0 to À25.0 kcal/mol, which indicate that the carbon dioxide insertion step proceeds very easily. And we found that species 4a is the most stable intermediate in benzene solution, which gives strong theoretical explanation for the observations of similar metallacarbonates [11,30]. On the whole, the high level calculations do not change the general trends for the reaction energy profiles.…”

Section: Solvent Effects and Overall Energeticssupporting

confidence: 63%

“…However, most catalysts, such as metalhalides [14,15], metal oxides [16,17], organometallic compounds [18][19][20], Lewis acid/bases [21], and zeolites [22], suffer from low catalytic activity or need harsh reaction conditions (high pressures of CO 2 and high temperatures), limiting their practicality. Some of these obstacles have been overcome with the development of metal (nickel, palladium, or platinum) complexes [28][29][30] that mediate the oxidative coupling of CO 2 with various epoxides. Among these transition metals, Ni appears great promise due to its inexpensiveness.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical study on the mechanism of nickel(0)-mediated coupling between carbon dioxide and epoxyethane

Guo

Zhang

Jia

et al. 2009

Journal of Molecular Structure: THEOCHEM

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Section: Solvent Effects and Overall Energeticssupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Theoretical study on the mechanism of nickel(0)-mediated coupling between carbon dioxide and epoxyethane

Guo

Zhang

Jia

et al. 2009

Journal of Molecular Structure: THEOCHEM

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“… The coordination chemistry of platinum( II ) compounds is subtly dependent upon the electronic and steric effects of ligands and coligands 11, 12. Moreover, the oxidation of Pt II to Pt IV compounds has been utilized in various aspects of platinum chemistry, such as mixed‐valence chain compounds, oral antitumor (pro)drugs, and reaction mechanisms 13–16…”

Section: The Plane Angle Between the Platinum(iv) Square And The Flu mentioning

confidence: 99%

Unusual Fluorenylidene-philic Interactions for Effective Conformational Induction

Lee

Jung

2001

Angew. Chem.

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The observation and modulation of unusual noncovalent interactions is of central importance in the field of functional molecules since the interactions play critical roles in the determination of structural motifs and reaction pathways. [1±5] Conformational equilibria have often been studied to deduce general structure ± stability relationships, and the results can be extended beyond the initial goal to such diverse areas as quantum-mechanical calculations, spectroscopic studies, molecular biology, chiral catalysts, and tunable receptors. [6±10] Switchable conformation through such specific interactions may serve in the development of sensing or recognition materials. Herein we report a systematic study of conformational induction by intramolecular fluorenylidene-philic interactions during the oxidative addition of [Pt II (fm)] to [Pt IV (fm)] complexes (fm 9-fluorenylidenemalonate). The coordination chemistry of platinum(ii) compounds is subtly dependent upon the electronic and steric effects of ligands and coligands. [11,12] Moreover, the oxidation of Pt II to Pt IV compounds has been utilized in various aspects of platinum chemistry, such as mixed-valence chain compounds, oral antitumor (pro)drugs, and reaction mechanisms. [13±16] Reaction of [Pt II (NO 3 ) 2 (dpda)] (dpda 2,2-dimethyl-1,3propanediamine) with fm afforded [Pt II (fm)(dpda)] (1). The oxidative addition of 1 with a 30 % aqueous solution of H 2 O 2 in methanol produced the mixed-axial hydroxo/methoxoplatinum(iv) complex trans,cis,cis-[Pt IV (OH)(OCH 3 )(fm)-(dpda)] (2) in 81.3 % yield. When ethanol was used as solvent instead of methanol, the oxidative addition gave an ethoxo analogue. The structure of 2 was confirmed by an X-ray crystallography [17] (Figure 1), and the relevant bond lengths and angles are not exceptional. The local geometry around the platinum atom approximates to a typical octahedral arrangement with the added hydroxo/methoxo ligands in trans coordination sites. The 9-fluorenylidene (flu) moiety is bent towards the methoxo group instead of the smaller hydroxo group, and snugly interacts with the methoxo group. The distances C22´´´C9 (C22ÀH´´´C9) and O5´´´C9 are 3.45 (2.75 ) and 3. 47 , respectively, which are comparable to usual values for a CÀH´´´p interaction. [4,18] The substitution reaction of 2 with acetic anhydride gives trans,cis,cis-[Pt IV (OOCCH 3 )(OCH 3 )(fm)(dpda)] (3) in 80.3 % yield. The crystal structure analysis of 3 (Figure 1) [17] shows that the molecular configuration is retained during the reaction of 2 to 3. Interestingly, in 3 the flu moiety is directed towards the OOCCH 3 group. Thus, the axial acetato group lies parallel to the flu moiety at distances usual for C(H)´´´p interactions (O6´´´C9, 3.33 ), indicating that the flu moiety prefers an acetato to a methoxo group.The aliphatic region of 1 H NMR spectra of 1 and 3 in N,Ndimethylformamide are depicted in Figure 2. Resonances were assigned by 1 H/ 13 C COSY NMR spectroscopy (see Supporting information). The proton resonances of 1 exhibit a marked ...

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“…By the reaction of [PtMe 2 (NN)] (NN = 2,2Јbipyridine, bpy, or NN = 1,10-phenanthroline, phen), which bears an electron rich platinum() centre, with oxiranes and carbon dioxide, it has been possible to prepare a series of cyclic platinacarbonate complexes. 4,5 In this study, this cycloaddition reaction has been performed using [Pt{(CH 2 ) 4 }(NN)], 1, to prepare tris-chelate organoplatinum() complexes, each containing a cyclic metallacarbonate ring. These are important complexes, as the metallacycles are of considerable interest because of their possible role in catalysis, 6,7 and also organometallic tris-chelate complexes are not common.…”

Section: Introductionmentioning

confidence: 99%

Organoplatinum(iv) tris-chelate complexes, each having a cyclic metallacarbonate ring: synthesis, characterization and kinetic studies of the formation

2004

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The complexes [Pt[(CH2)4](NN)], 1a (NN = 2,2'-bipyridine) and 1b (NN = 1,10-phenanthroline) react with 2,3-epoxypropylphenyl ether in the presence of CO2 to give tris-chelate platina(IV)cyclopentane complexes characterized by 1H and 13C NMR spectroscopy as [Pt[(CH2)4](CH2CHCH2OPhOCO2)(NN)], 2. The reactions proceed by the SN2 mechanism and the rates were independent of concentration of CO2. It is demonstrated that for 1a, the reaction proceeds 2.32 times faster than the similar reaction in which the dimethyl analog, [PtMe2(2,2'-bipyridine)], is used. The analog tris-chelate complex [Pt[(CH2)4](CH2CHPhOCO2)(phen)], 3a, was similarly synthesized.

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Stereochemistry of the oxidative addition of an epoxide to platinum(II): relevance to catalytic reactions of epoxides

Cited by 39 publications

References 0 publications

Theoretical study on the mechanism of nickel(0)-mediated coupling between carbon dioxide and epoxyethane

Theoretical study on the mechanism of nickel(0)-mediated coupling between carbon dioxide and epoxyethane

Unusual Fluorenylidene-philic Interactions for Effective Conformational Induction

Organoplatinum(iv) tris-chelate complexes, each having a cyclic metallacarbonate ring: synthesis, characterization and kinetic studies of the formation

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