Eine einfache methode zur n-alkylierung von β-lactamen

Reuschling, D.; Pietsch, H.; Linkies, Adolf

doi:10.1016/s0040-4039(01)85347-8

Cited by 44 publications

(13 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, only highly reactive electrophiles gave satisfactory levels of conversion and yields, probably because of the low nucleophilicity of the nitrogen atom. Good yields can be obtained by phase‐transfer catalysis methodology (KOH/ n Bu 4 NBr/THF) as described by Reuschling et al,56 despite the risks of side reactions or nucleophilic opening of the β‐lactam ring.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of α,α‐Difluoro‐β‐amino Esters or gem‐Difluoro‐β‐lactams as Potential Metallocarboxypeptidase Inhibitors

et al. 2008

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis of α,α‐Difluoro‐β‐amino Esters or gem‐Difluoro‐β‐lactams as Potential Metallocarboxypeptidase Inhibitors

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Alkylation of P-Laclams.-Method A. 26 Tetrabutylammonium hydrogen sulfate (1-4 mmol 0.1 mol equiv.) powdered potassium hydroxide (1.4 rnol equiv.)…”

Section: Methodsmentioning

confidence: 99%

Study of the transamidative ring expansion of N-ω-halogenoalkyl-β-lactams of alkyl chain lengths 2–12 in liquid ammonia and other liquid amines: syntheses of 7-, 8- and 9-membered 1,5-diaza cyclic ketones, including routes to (±)-dihydroperiphylline and (±)-celabenzine

Begley¹,

Crombie²,

Haigh³

et al. 1993

J. Chem. Soc., Perkin Trans. 1

View full text Add to dashboard Cite

N-(3-Halogenopropyl) -4-phenylazetidin-2-ones undergo amination in liquid ammonia followed by transamidative ring expansion to give the eight-membered 4-phenyl-l,5-diazacyclooctan-2-one in excellent yield. Ring expansion of the amines in liquid ammonia is found to be much more effective than in hydrocarbon solvents. Formation of 7-, 8-, and 9-membered azalactams from the requisite o-halogenoalkyl-p-lactams is an excellent synthetic process, though it is not applicable to 10membered rings. In the cases of rings of 13-, 15-and 17-members, although amination and apparent expansion takes place, the large rings appear not to be stable to ammonia and the final products are acyclic amides. N -[4-Halogenobut-2(Z) -enyl] -4-phenylazetidin-2-one satisfactorily forms a 9-membered (Z)-olefinic azalactam. but the (€)-isomer gives an acyclic amino amide. By using alkyl-substituted p-lactam side-chains, C-substituted medium rings can be obtained; the relative instability of N-acyl j3-lactams to ammonia, however, leads to acylamino amides rather than expanded rings.Employing ethylamine in place of ammonia, it is shown that N-ethylated azalactams are formed satisfactorily, and using allylamine, N-ally1 medium rings capable of further elaboration are obtained. The chemistry of these systems is discussed. Using transamidation in liquid ammonia, a short synthesis of the 9-membered spermidine alkaloid ( k )-dihydroperiphylline is reported. Synthesis of key intermediates, whose transformation into the 13-membered alkaloids of the celabenzine group has already been effected, has been carried out.X-Ray single-crystal structure determinations for 4-phenyl-l,5-diazacyclononan-2-one, trans-4phenyl-8-methyl-1,5-diazacyclooctan -2-one and (Z) -4-phenyl-1,5-diazacyclonon-7-en-2-0ne are reported, and comment is made on certain conformational features.

show abstract

“…After the initial reports of cyclopropanation of olefins by photolysis of methylene iodide,2 Neuman and Wolcott examined the photolysis of 2,2-dimethyl-l,l-diiodopropane (1) in nonpolar solvents such as cyclohexane and cyclohexene. 4 They did not observe formation of 1,1-dimethylcyclopropane (2), which had been shown in previous (2) Blomstrom, D. C.; Herbig, K.; Simmons, . E. J. Org.…”

mentioning

confidence: 56%