On the conversion of biologically interesting amines to hydroxylamines

Wittman, Mark D.; Halcomb, Randall L.; Danishefsky, Samuel J.

doi:10.1021/jo00294a005

Cited by 87 publications

(39 citation statements)

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“…19 In brief, compound 1 was prepared in 36% overall yield from triacetyl glucal by a Ferrier rearrangement, followed by saponification, acetalization of the 4,6-diol, and benzylation of the remaining C3 alcohol. Perbenzylated allal 2 and 4-deoxyallal 3 were both prepared from 3,6-di- O -acetyl allal, which was generated from the Ferrier rearrangement intermediate in 59% yield by DMDO oxidation and Et 2 NH-mediated [2,3]-sigmatropic rearrangement with simultaneous acyl migration from O-4 to O-3.…”

Section: Resultsmentioning

confidence: 99%

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Stereoelectronic Factors in the Stereoselective Epoxidation of Glycals and 4-Deoxypentenosides

et al. 2011

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Glycals and 4-deoxypentenosides (4-DPs), unsaturated pyranosides with similar structures and reactivity profiles, can exhibit a high degree of stereoselectivity upon epoxidation with dimethyldioxirane (DMDO). In most cases, the glycals and their corresponding 4-DP isosteres share the same facioselectivity, implying that the pyran substituents are largely responsible for the stereodirecting effect. Fully substituted dihydropyrans are subject to a “majority rule,” in which the epoxidation is directed toward the face opposite to two of the three groups. Removing one of the substituents has a variable effect on the epoxidation outcome, depending on its position and also on the relative stereochemistry of the remaining two groups. Overall, we observe that the greatest loss in facioselectivity for glycals and 4-DPs is caused by removal of the C3 oxygen, followed by the C5/anomeric substituent, and least of all by the C4/C2 oxygen. DFT calculations based on polarized-π frontier molecular orbital (PPFMO) theory support a stereoelectronic role for the oxygen substituents in 4-DP facioselectivity, but less clearly so in the case of glycals. We conclude that the anomeric oxygen in 4-DPs contributes toward a stereoelectronic bias in facioselectivity whereas the C5 alkoxymethyl in glycals imparts a steric bias, which at times can compete with the stereodirecting effects from the other oxygen substituents.

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Section: Resultsmentioning

confidence: 99%

“…A solution of 3,6-di- O -acetyl-D-allal 36 (184 mg, 0.80 mmol) in 1:1 THF:CS 2 (18 mL) was treated with a 60% dispersion of NaH in mineral oil (97 mg, 2.40 mmol) at 0 ºC. After 15 min, the ice bath was removed and stirred for a further 30 min at rt, after which MeI (500 μL, 7.98 mmol) was added.…”

Section: Methodsmentioning

confidence: 99%

Stereoelectronic Factors in the Stereoselective Epoxidation of Glycals and 4-Deoxypentenosides

et al. 2011

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“…This reaction worked well on polyfunctional amines such as O-protected aminosaccarides 140 (equation 94), yet it was found to be substrate-sensitive and failed to provide hydroxylamines in several cases 286 …”

Section: Hydroxylamines Through Oxidation Of Aminesmentioning

confidence: 99%

Synthesis of Hydroxylamines

Melman

2010

Patai's Chemistry of Functional Groups

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Introduction Hydroxylamines through Hydrolysis of Hydroxamic Acids, Oximes and Nitrones Synthesis of Hydroxylamines through Alkylation and Arylation of other Hydroxylamines Hydroxylamines through Reduction Reactions Hydroxylamines through Addition to the C  N Double Bond of Oximes, Oxime Ethers and Nitrones Hydroxylamines through Addition to the N  O Double Bond of Nitroso and Nitro Compounds Hydroxylamines through Oxidation of Amines Hydroxylamines through Cycloaddition Reactions

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“…The spectra datal of the product were identical with those of authentic samples. [5] 2d: White crystals, mp 65 -67 8C; IR (KBr): n ¼ 3355, 2925, 1727, 1431, 1193 cm 136.9 (C), 175(CO). The spectral data of the product were identical with those of authentic samples.…”

Section: Monoalkylhydroxylamine 2fmentioning

confidence: 99%

“…[4] Other reported methods include the oxidation of a primary amine with dimethyldioxirane (this protocol is applicable to only a limited range of substrates), [5] and the indirect oxidation of primary amines, involving imine formation, oxidation, and oxaziridine hydrolysis [6] (this method is amenable to the synthesis of optically active hydroxylamines, although the acid-labile Schiff base is one of its disadvantages). The direct microwave-induced oxidation of primary amines with oxone over silica gel or alumina, [7] the three-step procedure involving cyanomethylation of primary amines, nitrone formation, and hydroxylaminolysis of the nitrones, [8] the asymmetric hydrogenation of nitrones with an iridium catalyst system, [9] the oxidation of primary amines to nitrones followed by hydrolysis under acidic conditions, or treatment with hydroxylamine to afford the desired N-alkylhydroxylamine (this protocol is applicable only to a limited substrates), [10] and finally the alkylation of amines with a-haloacetonitrile followed oxidation to give the convertible nitrone [11] should also be mentioned.…”

Section: Introductionmentioning

confidence: 99%

Oxidation of Primary Amines to N‐Monoalkylhydroxylamines using Sodium Tungstate and Hydrogen Peroxide‐Urea Complex

Heydari

Aslanzadeh

2005

Adv Synth Catal

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Abstract:The sodium tungstate-catalyzed (10 mol %) oxidation of primary amines with a urea-hydrogen peroxide complex (UHP) gives the corresponding N-monoalkylhydroxylamines, which are important biologically active compounds, in good to excellent yields. The method is applicable for a wide range of primary amines, including chiral benzylic amines, a-1,2-hydroxylamine and a-amino esters.Keywords: homogeneous catalysis; hydroxylamines; tungsten; urea-hydrogen peroxide complex a-Hydroxylamino acids and hydroxamic acids have important biological activities. The synthesis of their precursors, N-monoalkylhydroxylamines, has been a topic of considerable research interest.[1] Our investigations have revealed only few examples of the synthesis of Nmonoalkylhydroxylamines from primary amines. These involve the oxidation of the amine with an appropriate oxidation reagent such as benzoyl peroxide (this method requires treatment of an intermediate O-benzylated hydroxylamine with base in order to obtain the free hydroxylamine), [2] hydrogen peroxide or m-chloroperbenzoic acid (this often leads to overoxidation products such as nitroso and nitro compounds and is generally ineffective), [3] or the reduction of the corresponding nitroso and/or nitro compound, or oxime (this method is not applicable to the synthesis of optically active N-alkylhydroxylamines).[4] Other reported methods include the oxidation of a primary amine with dimethyldioxirane (this protocol is applicable to only a limited range of substrates), [5] and the indirect oxidation of primary amines, involving imine formation, oxidation, and oxaziridine hydrolysis [6] (this method is amenable to the synthesis of optically active hydroxylamines, although the acid-labile Schiff base is one of its disadvantages). The direct microwave-induced oxidation of primary amines with oxone over silica gel or alumina, [7] the three-step procedure involving cyanomethylation of primary amines, nitrone formation, and hydroxylaminolysis of the nitrones, [8] the asymmetric hydrogenation of nitrones with an iridium catalyst system, [9] the oxidation of primary amines to nitrones followed by hydrolysis under acidic conditions, or treatment with hydroxylamine to afford the desired N-alkylhydroxylamine (this protocol is applicable only to a limited substrates), [10] and finally the alkylation of amines with a-haloacetonitrile followed oxidation to give the convertible nitrone [11] should also be mentioned.In connection with our interest in one-pot, three-component coupling reactions involving 1,3-asymmetric induction of aldehydes, hydroxylamines and nucleophiles in a 5.0 M solution of lithium perchlorate in diethyl ether, [12] we required access to various optically active N-alkylhydroxylamines. In the course of these studies we encountered difficulties in the oxidation of primary amines to the corresponding hydroxylamines. We investigated a series of reagents for this transformation and discovered that using sodium tungstate (Na 2 WO 4 ) in the presence of the hydrogen peroxide/urea comple...

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On the conversion of biologically interesting amines to hydroxylamines

Abstract: Postdoctoral Fellowship to M.D.W. (Grant 1F32CA08641-01) is gratefully acknowledged.

Cited by 87 publications

References 1 publication

Stereoelectronic Factors in the Stereoselective Epoxidation of Glycals and 4-Deoxypentenosides

Stereoelectronic Factors in the Stereoselective Epoxidation of Glycals and 4-Deoxypentenosides

Synthesis of Hydroxylamines

Oxidation of Primary Amines to N‐Monoalkylhydroxylamines using Sodium Tungstate and Hydrogen Peroxide‐Urea Complex

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