Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H<sub>2</sub>O<sub>2</sub>, Part II: Catalytic Activities and Mechanism

Tse, Man Kin; Bhor, Santosh; Klawonn, Markus; Anilkumar, Gopinathan; Jiao, Haijun; Spannenberg, Anke; Döbler, Christian; Mägerlein, Wolfgang; Hugl, Herbert; Beller, Matthias

doi:10.1002/chem.200501262

Cited by 106 publications

(51 citation statements)

References 170 publications

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“…The amides 1a-e prepared in this way were then submitted to ring closure reaction which gave the oxazolines 2a-e. References [7,8,[21][22][23][24][25][26][27][28][29][30][31] describe many synthetic procedures using various reagents, however, these reagents sometimes fail in oxazoline synthesis. For example frequently used thionyl chloride [21,24,26,27] provides the respective chloro derivative which unfortunately does not undergo required intramolecular ring closure reaction in our case.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Drabina

Funk

Růžička

et al. 2010

Transition Met Chem

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The optically pure 6-(4-alkyl-4,5-dihydro-1,3-oxazol-2-yl)pyridine-2-carboxylates have been prepared from 6-methoxycarbonylpyridine-2-carboxylic acid by a sequence of three reactions with the overall yield of 40-50%. Some of these compounds form stable complexes with Cu(II) ions in non-aqueous medium. Their polymeric structure was determined in the solid phase by X-ray diffraction analysis. The Cu(II) complexes were also used as catalysts for addition reactions of terminal alkynes to imines giving substituted propargylamines with maximum yield 64% and 37% ee.

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Section: Resultsmentioning

confidence: 99%

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Drabina

Funk

Růžička

et al. 2010

Transition Met Chem

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“…as steps in the synthesis of natural products (cf. 2.3.3) and including pyranones [144], sialyl alcohols [145], glucals [146], pyrrolidinones [147], bicyclic ketones [148], acetals [149], synthesis of a vinyl oxirane [49], 3-alkylcyclopentenones [150] and hydroxycyclopentene [151]. Examples of lactolto-lactone oxidations effected by TPAP/NMO/PMS/CH 2 Cl 2 include a step for thapsigargin syntheses [152,153], and TPAP/NMO/PMS/CH 3 CN [64] for a tetrol to lactone oxidation [152].…”

Section: Specific Examplesmentioning

confidence: 99%

Oxidation of Alcohols, Carbohydrates and Diols

Griffith

2009

Catalysis by Metal Complexes

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This is one of the most important classes of oxidation effected by Ru complexes, particularly by RuO 4 , [RuO 4 ] − , [RuO 4 ] 2− and RuCl 2 (PPh 3 ) 3 , though in fact most Ru oxidants effect these transformations. The chapter covers oxidation of primary alcohols to aldehydes (section 2.1), and to carboxylic acids (2.2), and of secondary alcohols to ketones (2.3). Oxidation of primary and secondary alcohol functionalities in carbohydrates (sugars) is dealt with in section 2.4, then oxidation of diols and polyols to lactones and acids (2.5). Finally there is a short section on miscellaneous alcohol oxidations in section 2.6.In this chapter the first of the two most important categories of oxidations catalysed by Ru complexes (the other being alkene and alkyne oxidations in Chapter 3) are considered. The approach in this and subsequent chapters differs from that of Chapter 1, concentrating here on the substrate rather than on the oxidant. The text is divided into the categories of alcohols and their oxidations. There are summaries in section 2.3.6 of systems of limited applicability which are mentioned only in Chapter 1, and in section 2.3.7 of large-scale (>1 g) oxidations.The first oxidations of alcohols by stoicheiometric RuO 4 /H 2 O were reported in 1958, of primary alcohols to aldehydes or carboxylic acids and secondary alcohols to ketones [1]. The first Ru-catalysed oxidation of an alcohol was reported in 1965 when Parikh and Jones used RuO 2 /aq. Na(IO 4 )/CCl 4 1 ( Table 2.3) [2] to oxidise secondary alcohol groups in carbohydrates.Oxidation of alcohols is the most frequently reviewed topic for Ru-catalysed oxidations [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Mechanisms of alcohol oxidation by Ru complexes have been reviewed [21].

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“…The comparison of the structures of pybox and pyboxazine are discussed in detail with the aid of their ruthenium complexes. [23] …”

Section: Introductionmentioning

confidence: 97%

Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H₂O₂, Part I: Synthesis of New Chiral N,N,N‐Tridentate Pybox and Pyboxazine Ligands and Their Ruthenium Complexes

Tse

Bhor

Klawonn

et al. 2006

Chemistry A European J

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The synthesis of chiral tridentate N,N,N-pyridine-2,6-bisoxazolines 3 (pybox ligands) and N,N,N-pyridine-2,6-bisoxazines 4 (pyboxazine ligands) is described in detail. These novel ligands constitute a useful toolbox for the application in asymmetric catalysis. Compounds 3 and 4 are conveniently prepared by cyclization of enantiomerically pure alpha- or beta-amino alcohols with dimethyl pyridine-2,6-dicarboximidate. The corresponding ruthenium complexes are efficient asymmetric epoxidation catalysts and have been prepared in good yield and fully characterized by spectroscopic means. Four of these ruthenium complexes have been characterized by X-ray crystallography. For the first time the molecular structure of a pyboxazine complex [2,6-bis-[(4S)-4-phenyl-5,6-dihydro-4H-[1,3]oxazinyl]pyridine](pyridine-2,6-dicarboxylate)ruthenium (S)-2 aa, is presented.

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Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H₂O₂, Part II: Catalytic Activities and Mechanism

Cited by 106 publications

References 170 publications

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Oxidation of Alcohols, Carbohydrates and Diols

Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H₂O₂, Part I: Synthesis of New Chiral N,N,N‐Tridentate Pybox and Pyboxazine Ligands and Their Ruthenium Complexes

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Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H2O2, Part II: Catalytic Activities and Mechanism

Cited by 106 publications

References 170 publications

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Synthesis, copper(II) complexes and catalytic activity of substituted 6-(1,3-oxazolin-2-yl)pyridine-2-carboxylates

Oxidation of Alcohols, Carbohydrates and Diols

Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H2O2, Part I: Synthesis of New Chiral N,N,N‐Tridentate Pybox and Pyboxazine Ligands and Their Ruthenium Complexes

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Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H₂O₂, Part II: Catalytic Activities and Mechanism

Ruthenium‐Catalyzed Asymmetric Epoxidation of Olefins Using H₂O₂, Part I: Synthesis of New Chiral N,N,N‐Tridentate Pybox and Pyboxazine Ligands and Their Ruthenium Complexes