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1.
N,O-bis(diphenylphosphinyl)-2-(hydroxymethyl)aziridine (‘DiDpp’, 1) is efficiently prepared from 2-aminoethane-1,3-diol: this activated aziridine undergoes two sequential reactions with copper(I)-modified Grignard reagents, yielding α-branched N-Dpp amines in good yield. 相似文献
2.
Jean-Marc Bourgeois 《Helvetica chimica acta》1974,57(8):2553-2557
Treatment of 3-C-cyano-1,2:5,6-di-O-isopropylidene-3-O-(toluene-p-sulfonyl)-α-D -allofurannose with AlLiH4 or RMgX yields spiro-aziridines with two identical substituents on C(3′) (? H, ? CH3, ? C2H5). Reactions of these products and their derivatives are briefly described. If the C(3′) substituents are protons, the aziridine ring is easily opened. In acidic media (HCl), an amino-sugar containing the branched chain ? CH2Cl is produced; with hydrogenation, a ? CH3 branched chain results. If the C(3′) substituents are methyl groups, the aziridine ring cannot be opened neither with HCl nor with hydrogen. The acetylated derivative of this latter compound rearranges to the corresponding allylamide with HCl. For both types of spiro-aziridine, the nitrous deamination leads to the corresponding alkene. 相似文献
3.
Dr. Hong Yi Prof. Dr. Martin Oestreich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(26):6505-6507
A stereospecific ring opening of various 2-aryl-substituted aziridines with silicon Grignard reagents under copper catalysis is reported. The regiochemical outcome is governed by the steric demand of the silicon nucleophile. The LiCl introduced with the magnesium reagent R3SiMgX⋅2 LiCl is shown to enhance the SN2-type displacement of the carbon-nitrogen bond by coordination to the aziridine nitrogen atom. 相似文献
4.
The reaction of silyldibromomethyllithium with aromatic imines provides alpha-amino acylsilanes via a bromo aziridine intermediate upon quenching the reaction with water. Alternatively, treatment of the bromo aziridine intermediate with various Grignard reagents or lithium aluminum hydride permits the nucleophilic displacement of the halogen to furnish substituted silyl aziridines. 相似文献
5.
From 9H-amino [l]benzopyranno-as-triazines 2 and 3 , [l]ben-zopyranno[4,3-e] or [3,4-e]pyrimido[l,2-b]-as-triazinones have been prepared by reaction with β-ketoesters. Chemical reduction of the compounds gives tetrahydro derivatives. By electrochemical reduction the dihydro compounds 14 and 15 were from-ed. The same dihydro derivatives were obtained with Grignard reagents. 相似文献
6.
Electrochemical reduction of [1]benzopyranno[4,3-e]-as-triazinones gives 1,4-dihydro derivatives which can either rearrange into 4,4a-dihydro compounds or be reduced with ring contraction into benzopyranno-imidazolones. The reaction of Grignard reagents on benzopyrannotriazines leads to a reduction in –α position of the benzene ring (4,4a-dihydro). Electrochemical reduction gives the 1,4-dihydro derivative which rearrange into the 1,10a-dihydro compound. The 1,4-dihydro derivatives are reduced with triazine ring contraction to give benzopyrannoimidazoles. Dihydro-1,10a compounds can be reduced into imidazoles or into tetrahydro derivatives. 相似文献
7.
[reaction: see text] A stepwise formal [3 + 3] cycloaddition sequence via a Grignard addition-cyclization reaction leads to a much improved piperidine synthesis. This methodology provides improved flexibility in both the aziridine substrate and TMM equivalent. 相似文献
8.
The regio- and stereo-selective introduction of a difluoromethylene group in an allylic position is described. The key step is the treatment of 1,1-difluoro-1-alken-3-acetates with Grignard reagents in the presence of copper and lithium salts.
Résumé
Nous décrivons ici une méthode régio- et stéréo-sélective permettant l'introduction du groupement difluorométhylène en position allylique. L'étape principale est la réaction des 3-acétoxy-1,1-difluoro-1-alcènes avec les réactifs de Grignard en présence de sels de cuivre et de lithium. 相似文献
9.
The reactions of Grignard reagents with α-keto oximes 1 and α-hydroximino alcohols 3, give secondary aziridine alcohols 2 or 4, which with SOCL2 (or COCl2)give azabicyclo[3.1.0]oxo-2 oxaisothiazolidine-1, 5 or azabicyclo[3.1.0]carbamate-1,2,3 6. The determination of configuration of 2,4 and 5 was achieved by an NOE study. 相似文献
10.
Protonation of aziridines, which are potential azomethine ylides when the equilibrium aziridine?azomethine ylide is established, generally leads to functional iminium salts. A competition between N-protonation of the aziridine and C-protonation of the azomethine ylide may be observed. Factors governing the different acido-basic equilibriums are discussed. 相似文献
11.
J. Nicolas Roedel Roman Bobka Bernd Neumann Birgit Weber Peter Mayer Ingo‐Peter Lorenz Prof. Dr. 《无机化学与普通化学杂志》2007,633(8):1171-1177
The synthesis and characterization of mononuclear tetrakis‐aziridine nickel(II ) and copper(II ) complexes as well as of a dinuclear bis‐aziridine copper(II ) complex are described. The reactions of anhydrous MCl2 (M = NiII, CuII) with aziridine (= az = C2H4NH, C2H3MeNH, CH2CMe2NH) in CH2Cl2 at room temperature in a 1:5 and 1:2 molar ratio, respectively, afforded the tetrakis‐aziridine complexes [M(az)4Cl2] (M = Ni, Cu) or the dimeric bis‐aziridine complex [Cu(az)2Cl2]2. After purification, all of the complexes were fully characterized. The single crystal structure analysis revealed two different coordination modes. Whereas both nickel(II ) complexes can be classified as showing an elongated octahedral structure, copper(II ) complexes show either an elongated octahedral or a square pyramidal arrangement forming dimers with chlorido bridges in axial positions. Furthermore, the results of magnetic measurements of the nickel(II ) and copper(II ) compounds are presented. 相似文献
12.
[reaction: see text] A stereocontrolled route to Nuphar alkaloids is described that employs a formal [3 + 3] cycloaddition strategy to assemble the piperidine nucleus. The addition of Pd-TMM complexes to aziridine 10 was found to be sluggish; however, the addition of a functionalized allyl Grignard reagent followed by a Mitsunobu condensation reaction provided 11 in high yield. The employment of this route in the formal synthesis of (-)-deoxynupharidine 1 is described. 相似文献
13.
Catherine Cloutour Caroline Debaig-Valade Catherine Gacherieu Jean-Claude Pommier 《Journal of organometallic chemistry》1984,269(3):239-247
A comparative study of alkylation by Grignard reagents of PSn(OH)2 (P = tetraphenylporphyrin (TPP), tetraphenylchlorine (TPC), tetraphenylisobacteriochlorine (TPiBC)) shows that dialkylstannylisobacteriochlorines are the most easily obtained. The presence of transition metals in the magnesium crystals directs the reaction towards reduction of the macrocycle instead of alkylation on tin. This is supplementary proof for the intervention of a single electron transfer mechanism (SET) in alkylation of a macrocycle by Grignard reagents.These results fit very well with earlier electrochemical experiments and the measurements of the reduction potentials of the Group IVB metalloporphyrins and their reduced forms. 相似文献
14.
Joëlle Mayrargue Michel Duchon D'Engenires Marcel Miocque 《Journal of heterocyclic chemistry》1978,15(2):263-267
By cyclization in aqueous media, 2-aminomethyl 1-alcynyl 1-cyclohexanols lead to perhydroisoindolinium or perhydroisoquinolinium salts. The stereochemistry of isolated diastereoisomers is elucidated. A stereoselectivity favouring trans junction of the rings is pointed out. 相似文献
15.
A. Lopez M. M. Gauthier R. Martino A. Lattes 《Magnetic resonance in chemistry : MRC》1979,12(7):418-428
Although nitrogen inversion in unsubstituted aziridines has been shown by 1H NMR, it was only possible to study quantitatively the distribution of both invertomers and determine the thermodynamic parameters by a systematic high field NMR study (CAMECA 250 MHz). Thermodynamic parameters have been determined for 32 compounds. In C-aryl aziridines, the steric hindrance of the aromatic group and its variation with other aziridine ring substituents can be studied. These observations are in agreement with a conjugation phenomenon between the aromatic system and the aziridine ring. 相似文献
16.
From the ASIS effect on chemical shifts and from solvent and temperature dependence of the vicinal spin-spin coupling constant of 1-tertiobutyl 2-formyl aziridine, the following conclusion is reached: the less polar rotamer is the s-trans rotamer, which is of lower energy than the s-cis rotamer. 相似文献
17.
Whereas alkyl lithium and Grignard reagents both at rt and at −80°C thermally react with 3-methylisoxazolo[5,4-b]pyridine giving alkylation and/or isoxazole ring opening products, sodium malonate and sodium boron hydride react only under UV irradiation. Selective trappings of ketenimine or azirine intermediates give an enaminopyridone or two diasteroisomeric spiroaziridinopirydones. Regioselective opening of the aziridine ring with perchloric acid gives 3(1-amino-ethyl)-1H-pyridin-2-one. 相似文献
18.
By the action of pyridine on various Grignard reagents at room temperature, new diorganomagnesium complexes R2Mg · 2pyridine (R=Ph, n-Bu, t-Bu and Et) were prepared and analyzed. Anomalous results were obtained with methyl- or benzylmagnesium reagents. 相似文献
19.
Jacques Delaunay Alain Lebouc Olivier Riob 《Magnetic resonance in chemistry : MRC》1979,12(5):278-281
The 1H NMR study of 2-alkyl-3-chlorotetrahydropyrans, obtained by reaction of Grignard reagents with a mixture of cis/trans-2,3-dichlorotetrahydropyrans, shows cis/trans configuration of two isomers in which the alkyl substituents are exclusively in the equatorial position. 3-Chloro-2-phenyltetrahydropyran exists in trans (eq-eq) configuration only. The 1H NMR study of cis/trans 2-alkoxy (or aryloxy)-3-chlorotetrahydropyrans, obtained by reaction of alcohols or phenol with 2,3-dichlorotetrahydropyrans, shows the axial position of the alkoxy (or aryloxy) substituent. 相似文献
20.
Stereoselective Synthesis of Polycycles Containing an Aziridine Group: Intramolecular aza‐Diels–Alder Reactions of Unactivated 2H‐Azirines with Unactivated Dienes
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Dr. Hua‐Dong Xu Hao Zhou Ying‐Peng Pan Xin‐Tao Ren Hao Wu Mei Han Run‐Ze Han Dr. Mei‐Hua Shen 《Angewandte Chemie (International ed. in English)》2016,55(7):2540-2544
Vinyl azide with a pendent diene can undergo thermal decomposition to a related azirine intermediate, which was used immediately in an intramolecular aza‐Diels–Alder reaction to furnish an aziridine‐containing trans‐fused tricyclic core structure with excellent stereoselectivity. The method provides a facile entry to complex polycyclic alkaliods which can be further elaborated by ring‐opening reactions and ring expansion of the aziridine moiety, as well as by dihydroxylation of the alkene group. 相似文献