Lead(IV) coordination chemistry: alcohol oxidation

Partch, Richard; Monthony, James F.

doi:10.1016/s0040-4039(01)89527-7

Cited by 17 publications

(2 citation statements)

References 12 publications

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“…The enhancement of the radical reactivity of LTA under the influence of bases has been reported previously for several reactions, e.g., the oxidation of primary alcohols, the oxidative decarboxylation of carboxylic acids, 1b, and the thermal decomposition itself . For reactions run in the presence of carboxylate anions, Benson et al14b proposed an explanation based on the formation of a hexaliganded complex of Pb(IV) (Scheme ), even if only a few articles have described such high-coordination lead species. 1b, Intermediates of this type are implicitly supposed to undergo homolysis preferentially 1b…”

Section: Resultsmentioning

confidence: 80%

Sonochemical Reactions of Lead Tetracarboxylates with Styrene

et al. 1998

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Section: Resultsmentioning

confidence: 80%

Sonochemical Reactions of Lead Tetracarboxylates with Styrene

et al. 1998

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“…31 Direct evidence for the existence of aryllead(IV)-pyridine and aryllead(IV)-acetonitrile adducts was recently established using ESI mass spectrometry. 32 In the light of the obvious importance of pyridine, and more generally amine ligands in the chemistry of lead(IV), we were intrigued by a report of the isolation of a LTA-pyridine complex, 33 and present here a re-investigation of that work, including results from a detailed structural analysis of this complex using a combination of crystallographic, and solidstate and solution multinuclear NMR techniques. …”

Section: Introductionmentioning

confidence: 99%

Structural investigations of a lead(iv) tetraacetate–pyridine complex

et al. 2005

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A 1 : 1 crystalline complex of lead(IV) tetraacetate and pyridine (LTA-py) has been prepared. The single-crystal X-ray structure, at 296 and 150 K, establishes the presence of a relatively short Pb-N bond (2.307 A) within an intriguing seven-coordinate lead inner sphere consisting of the pyridine ligand and two bidentate and two monodentate acetate ligands. The pyridine occupies a surprising amount of the available coordination space and has induced a dramatic change in coordination compared to the four chelating acetate ligands found in lead tetraacetate (LTA). Thermal measurements (TGA/DSC) indicate the de-coordination of pyridine and its loss from the solid between 360 and 380 K. (207)Pb CP/MAS NMR spectroscopy also demonstrates the existence of the Pb-N bond through observation of (1)J((207)Pb,(14)N)= 63 Hz and a (207)Pb-(14)N dipolar coupling constant, of 149 Hz. The solid-state (207)Pb NMR parameters are used to give insight into the coordination environment of Pb(iv) in LTA-py. In solution, ligand exchange is rapid on chemical shift and J-coupling time scales. A (207)Pb NMR study of the titration of an LTA solution by pyridine yields a stability constant for LTA-py of K = 1.5 M(-1) and predicts it to have a (207)Pb NMR chemical shift essentially identical to that observed by CP/MAS NMR in the solid state. This correlation between the solid state and solution indicates that the seven-coordinate LTA-py structure found in the crystalline state does persist in solution, and this could further explain why the addition of pyridine has such profound effects on lead(IV) carboxylate-mediated organic reactions. Simulations of exchange-broadened line shapes of (13)C CP/MAS NMR spectra in the temperature regime above 280 K indicate local motion of the pyridine rings in the form of 180 degrees jumps (activation energy 72.5 kJ mol(-1)); these are first such ring flips reported for a coordinated pyridine ligand.

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Oxidative Decarboxylation of Acids by Lead Tetraacetate

Sheldon

Kochi

2011

Organic Reactions

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Lead tetracetate, one of the most versatile oxidizing agents know in organic chemistry, is capable of reacting with a variety of common functional groups; its use in organic chemistry has been reviewed. The purpose of this chapter is to review the oxidative process involving the decarboxylation of acids, whereby carboxylic acids are converted to a variety of compounds depending on experimental conditions, e.g, solvent, structure of substrates, and presence of additives. The primary objective here is to evaluate critically the usefulness of this reaction in organic synthesis. Decarboxylation of alpha‐hydroxy and alpha‐amino acids by lead tetraacetate has been known for many years. Khararaschn and co‐workers reported exhaustive products studies of the decomposition of lead tetraacetate in acetic acid. Sodium acetate accelerates the reduction of lead tetraacetate but no carbon dioxides liberated. Mosher and Kahr also examined the thermal decomposition of various organic acids by lead tetraacetate. Since then many studies on the mechanism and synthetic utility of these reaction and its modifications have been reported.

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Lead(IV) coordination chemistry: alcohol oxidation

Cited by 17 publications

References 12 publications

Sonochemical Reactions of Lead Tetracarboxylates with Styrene

Sonochemical Reactions of Lead Tetracarboxylates with Styrene

Structural investigations of a lead(iv) tetraacetate–pyridine complex

Oxidative Decarboxylation of Acids by Lead Tetraacetate

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