Aziridinyl alcohol

Solvolysis of tosylate (303) yields, in addition to aziridinyl alcohol (304), ring expanded products (305) and (306) (68TL6179). These products and the observed rates of solvolysis were explained in terms of bicyclic intermediate (301). 

On the other hand, approaches to the use of catalytic amounts of chiral ligands have been developed. Thus, the use of a sub-stoichiometric amount (50 mol%) of DBNE (1) affords A,A-diphenylphosphinylamine with 85% in 69% yield121a. Similarly, 25 mol% of chiral aziridinyl alcohol 56 (R = - ) affords (V,(V-diphenylphosphinylamine with 65% in 60% yield123. In the enantioselective addition reaction of diethylzinc to a nitrone, 20 mol% of the metal alkoxide of diisopropyl tartrate 62 catalyzed the formation of a... 

Aziridines can also be employed as nucleophiles. When one of the carbon atoms in the aziridine ring is equipped with an electron-withdrawing substituent, these substrates can often be cleanly deprotonated and used for subsequent carbanion chemistry. For example, the anion derived from the trifluoromethyl aziridine 162 engages in nucleophilic addition onto benzaldehyde to give the aziridinyl alcohol 163 in 83% yield <03TL6319>. Similarly, deprotonation of the oxazolinylaziridine 164 followed by treatment with methyl iodide gave mainly the methylated product 165 <03TL2677>. 

Stereoselective base catalyzed rearrangement of epoxy alcohols also of aziridinyl alcohols (see 1st edition)... 

All of the reactions of fluoroaziridines described above involve ring opening, but introduction of substituents onto an intact ring is an important addition to the reaction repertoire. Paralleling oxirane chemistry (e.g., 34-36), chiral aziridine 147 was deprotonated with butyllithium at — 102°C, and the resulting anion 201 was allowed to react with a variety of electrophiles." They included aldehydes, ketones, halides, and a disulfide. Reaction with benzaldehyde, for example, afforded aziridinyl alcohol 202 with preservation of configuration in 82% yield. 

A new type of aza-Payne rearrangement was reported by Bilke et al in which oxiranyl carbaldimines 40 upon treatment with lithiumorganic nucleophiles, are transformed to aziridinyl alcohols 41 regio-and diastereoselectively. This is the first case wherein an amine anion is generated as an intermediate by the attack of a nucleophile on an imine functionality. They suggested that this aza-Payne rearrangement reaction is fully supported by quantum chemical calculations of structural and electronical properties of the lithiated intermediates and transition states on the SCS-MP2/6-31+G //RHF/6-31+G level. 

Dogan and Garner developed a novel chiral aziridinyl alcohol ligand for Zn(II)-catalyzed [3 + 2] cycloadditions of azomethine ylide (Scheme 4.25) [25]. 

The action of nitrous acid on the benzodiazepine A -oxide 38 gives the nitrosoamino derivative 39,234 which reacts with alcohols, ethanethiol and various amino compounds, such as hydrazines and guanidine, by replacement of the methyl(nitroso)amino group.235 Reaction with aziridine affords the aziridinyl compound 40f or the 2-(aziridin-l-yl)ethylainino derivative 40g, depending on the conditions. 

The addition of aziridinyl anions to aldehydes gave the alcohols 31 in good yields15. As with the oxiranyl anions, the diastereoselectivity of the addition reaction could be substantially enhanced by transmetalation of the lithium reagent with chlorotris(dimethylamino)titanium. 

Corresponding reduced rings (cf 38, 40) can be obtained from a-aziridinyl heterocycles (37, 39). Related ring systems are obtained by formation of an alternative C—N bond, e.g. the alcohol (41) on heating with sulfuric acid affords racemic tetramisole (42) (68JOC1350). 

For synthesis of N-substituted aziridinyl ketones, primary amines such as methylamine [11, 12, 13], cyclohexylamine [8, 11, 14, 15, 16, 17] and benzyla-mines [17, 18, 19, 20] are introduced in the reaction instead of ammonia. These reactions can be carried out in different solvents, such as alcohols, benzene, toluene, dimethylformamide, etc. On the basis of this chemistry, aziridinyl ketones containing either one or more three-membered cycles can be synthesized (e.g., compounds 7 and 10 Scheme 1.3). 

Another synthetic method for the preparation of aziridinyl ketones involves the initial modification of unsaturated ketones, with formation of /3-methoxyamino derivatives, followed by treatment with either metal alcoholates [11, 28, 29, 30, 31], or hydroxylamine hydrochloride and then potassium hydroxide [32]. An obvious drawback of this approach is the possibility of obtaining an exclusively unsubstituted nitrogen atom for the aziridinyl ketones. Among the advantages are high yields for these reactions. For example, Jin et al. [31] recorded yields of aziridine 18 of 99%. In other publications the yields of target compounds were reported to be around 90%. 

The 14)3-pregn-16-en-20-one system (199) undergoes conjugate additions from the -face, appropriate reagents giving the 16) -cyano- (200), acetylthio- (201), nitromethyl (202), and aziridinyl (203) derivatives. Alkali-catalysed addition of alcohols failed in the 14 -series, although it is well-known in the 14a-isomers. 

Chem. Descrip. 1-Aziridinepropanoicacid, 2-methyl-2-ethyl-2-[[3-(2-me-thyl-1-aziridinyl)-1-oxopropoxy] methyl]-1,3-propanediyl ester (99.7%) CAS 64265-57-2 EINECS/ELINCS 264-763-3 Uses Crosslinking agent for aq. acrylic or urethane coatings Features Improves water, alcohol, and print resistance inc. chem., stain, and abrasion resistance... 

Isopropyl titanium triisostearate Methacrylic acid 2-Methylacrylic acid 2-(2-oxo-imidazolidin-1-yl) ethyl ester Methyltrimethoxysilane Oleic aminoethylimidazoline PEG-3 dimethacrylate PEG-6 trimethylolpropane Pentaerythrityl-tris-(B-(N-aziridinyl) propionate Polyethylenimine Propylene/MA copolymer PVPA/A copolymer Rosin, polymerized Styrene/allyl alcohol copolymer Styrene/MA copolymer Tallowaminopropylamine Tetraisopropyl di (dioctylphosphito) titanate Triallylcyanurate Tricaprylyl methyl ammonium chloride Trimethylolpropane tris-(B-(N-aziridinyl) propionate) Tris [1-(2-methyl-aziridinyl) phosphine oxide] adhesion promoter, acrylic resins... 

Pentaerythrityl-tris-(B-(N-aziridinyl) propionate Trimethylolpropane tris-(B-(N-aziridinyl) propionate) aquaculture Docosahexaenoic acid arachidyl alcohol source Arachidic acid arc lamps, mercury vapor Mercury... 

Ethylhexanol Glyceryl hydroxystearate Isostearyl alcohol Linoleyl alcohol Methoxy tri propylene glycol acrylate Methyl acid phosphate Methyl methacrylate Mineral oil Nonoxynol-1 Nonoxynol-3 Octyl acrylate Oleic amidoethylimidazoline PEG-8 ditallate PEG-12 ditallate PEG-115M Pine lignin Poloxamer 124 Polyaspartic acid homopolymer, sodium salt Polybutene Polychlorinated biphenyls Polyvinyl alcohol (partially hydrolyzed) Sodium alum Sodium sulfite Sorbose Stearyl hydroxyethyl imidazoline Triacetin Trimethyl-1,3-pentanediol, 2,2,4-diisobutyrate Tris [1-(2-methyl-aziridinyl) phosphine oxide] paper additive... 

FR-900482 918, a mitomycin-like antitumor agent, isolated from Streptomyces sandaensis, exists as a 2 1 mixture f> a ether bridge) of stereoisomers at neutral pH, but almost exclusively as the j8-isomer in acidic media. An asymmetric route to its core nucleus involves the cyclization of an aziridinyl radical derived from 914 to give a functionalized indole nucleus 915 —> 916. In a further step, a bmzyloxy-carbonyl group is introduced on the primary alcohol function using CDI and benzyl alcohol, affording 917 in 71% yield [659]. 

Another interesting protocol for triquinane synthesis is illustrated here. Thermal reaction of epoxy-A-aziridinyl imines in refluxing toluene initially generates the reactive alkylidene carbine, which undergoes intramolecular insertion reaction and a radical cascade to afford the tricyclic alcohol (Scheme 6.38). The triquinane thus formed can be easily converted to hirsutene as depicted [42]. 

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