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Aziridines from oximes

Table 14 Preparation of Aziridines from Oximes (Quaternary Hydrazones) and Grignard Reagents... Table 14 Preparation of Aziridines from Oximes (Quaternary Hydrazones) and Grignard Reagents...
Aziridines from oximes or from a-haloimines via azirines (see 1st edition). [Pg.164]

Lithium tetrahydridoaluminate Aziridines from oximes Stereospecific reduction... [Pg.124]

Azirines (three-membered cyclic imines) are related to aziridines by a single redox step, and these reagents can therefore function as precursors to aziridines by way of addition reactions. The addition of carbon nucleophiles has been known for some time [52], but has recently undergone a renaissance, attracting the interest of several research groups. The cyclization of 2-(0-tosyl)oximino carbonyl compounds - the Neber reaction [53] - is the oldest known azirine synthesis, and asymmetric variants have been reported. Zwanenburg et ah, for example, prepared nonracemic chiral azirines from oximes of 3-ketoesters, using cinchona alkaloids as catalysts (Scheme 4.37) [54]. [Pg.134]

Aziridines from reduction of oximes with lithium aluminum hydride, 48,23... [Pg.69]

Azirines have also been shown to be likely intermediates in the Campbell aziridine synthesis.62 This reaction is analogous to the Neber reaction in which the intermediate azirine is hydrolyzed to the aminoketone. Here the proposed azirine intermediate prepared from oxime (144) reacts with a Grignard reagent to give the aziridine (145). [Pg.70]

Aziridines can also be synthesized via azirine intermediates generated from oxime derivatives. Treated with triethylamine in methanol, oxime tosylate 157 cyclizes to azirine 158, which adds methoxide on the less hindered face to give aziridine 159 in 70% yield. ... [Pg.26]

Palacios, R Ochoa de Retana, A.M. Alonso, J.M. Regioselective synthesis of fluoroalkylated 3-aminophosphorus derivatives and aziridines from phosphorylated oximes and nucleophilic reagents. J. Org. Chem. 2006, 71, 6141. [Pg.58]

Lithium tetrahydridoaluminate Aziridine ring from oximes... [Pg.438]

Oxime 26 was prepared from 5,ll-dihydro-dibenzo[a,d]cyclohepten-10-one. The Hoch-Campbell reaction of 26 with 3-dimethylaminopropylmagnesium bromide produced aziridine 27 in 46% yield after acidic workup. Extension of the Hoch-Campbell reaction to steroids has also been reported. Thus, treatment of 3(3-hydroxy-5-pregnen-20-one oxime (28) with methylmagnesium iodide furnished a mixture of diastereomers, 20ot/20P,21-imino-20-methyl-5-pregnen-3P-ol (29) in a 50% combined yield and a 3 1 ratio. On the other hand, homo-adamantan-4-one oxime (30) was transformed to homo-adamantano[4,5-b]-2 -ethylaziridine (31) in 76% yield upon the action of... [Pg.24]

In some very early work the conformation of a-methyl groups in cyclohexanone oximes (76) was assigned from solvent shifts. Results are summarized in Table 17. In solutes bearing a lone pair of electrons on nitrogen, the benzene-solute collision complex is likely to occur at a site as far as possible from the nitrogen. Shifts have been summarized for aziridines, oximes and imines, and for the latter a complex of type 77 was proposed. [Pg.113]

In some cases 0-substituted oximes reacted with azomethine ylides. Thus, reaction of 0-substituted oxime (NC)2C=NOTs 139 with azomethine yhde derived from aziridine 140 afforded imidazoline 141 in 44% yield (equation 61). Addition of lithium derivative of silylated alkyne to oxime ethers 142 leads to 4-ethynyl-Af-hydroxy-2-imidazolines 143 in 49-72% yields (equation 62) . [Pg.254]

When cyclohexanone oxime 6e was used as amination reagent, primary amines were obtained from phenylmagnesium bromide. Reaction of 6e with alkyl Grignard reagents gave aziridines, whereas reaction with phenyllithium gave aziridine and the addition product of phenyllithium to the imine (Scheme 57) 24. [Pg.334]

Ethylenimines or aziridines [lb] can be considered cyclic imines and are only briefly covered in Section 5. The preparation of heterocyclic imine systems, semicarbazones, hydrazones, azines, and oximes, is omitted from this chapter. The synthesis of carbodiimides is presented in Chapter 9. [Pg.379]

Aroylaziridine oximes are accessible from aromatic nitrile oxides and aziridines and can rearrange... [Pg.8]

When electron-withdrawing groups are present on both the carbon and nitrogen atoms of the oxime, triazoline adducts ranging in yield from 23 to 89% are obtained by reaction with diazomethane or diazoethane (Scheme 102) the aziridines formed from these triazolines are found to show unusual configurational stability.363,364... [Pg.287]

Other types of allylic amination reactions include a variety of indirect approaches such as reduction of a,P-unsaturated imines and oximes, rearrangement of aziridines, and elimination of water from vicinal amino alcohols. However, these reactions will not be considered in this chapter [2]. [Pg.4]

Chiral aziridines can be prepared by the cycloaddition of chiral trifluoromcthyl-substituted oximes with diazomethaiie. Primary cycloadducts resulting from 1,3-dipolar cycloaddition are further decomposed to provide the aziridines. ... [Pg.557]

An interesting route to generate type I aziridines which is formally the formation of bond b is shown in Equation (5) <2002BML3141>. Oxime 21 is prepared in high yield from the corresponding tetralone. Reduction of oxime 21 with LiAlH4 and diethylamine in tetrahydrofuran (THE) provides the unprotected type I aziridine 22 in good yield. [Pg.111]


See other pages where Aziridines from oximes is mentioned: [Pg.61]    [Pg.74]    [Pg.125]    [Pg.61]    [Pg.74]    [Pg.125]    [Pg.90]    [Pg.90]    [Pg.90]    [Pg.90]    [Pg.52]    [Pg.1434]    [Pg.85]    [Pg.89]    [Pg.25]    [Pg.695]    [Pg.87]    [Pg.85]    [Pg.89]    [Pg.85]    [Pg.89]    [Pg.64]    [Pg.169]   
See also in sourсe #XX -- [ Pg.1555 ]




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Aziridines. synthesis from oximes

From aziridines

From oximes

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