Azetidines, Azetines, and Azetes: Monocyclic

Kimpe, Norbert De

doi:10.1016/b978-008096518-5.00018-6

Cited by 51 publications

(23 citation statements)

References 627 publications

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“…The complexity of the spectra in these compounds required the unambiguous elucidation of every proton, which was done by two-dimensional techniques (COSY and/or HETCOR). For compound 23 , J 2,3 = 5.8 Hz is in agreement with a syn stereochemistry, by comparison with reported data for related derivatives 31d. NOE irradiation of H3 on compound 23 resulted in an 11% enhancement of the signal corresponding to H2, which allows us to assign a syn H2−H3 stereochemistry.…”

Section: Resultssupporting

confidence: 85%

“…The planarity of the amide nitrogen, imposed by the amide resonance, is excluded in azetidines. Additionally, due to the interesting biological activity of some related tricyclic azetidines, the study was extended to azetidines 20c , d , derived from 2-azetidinones reactive toward P−K cyclization. Azetidines 20 were easily prepared by reduction of the corresponding β-lactams with excess of AlH 2 Cl (generated in situ from LiAlH 4 /AlCl 3 ) following the procedure reported by Ojima .…”

Section: Resultsmentioning

confidence: 99%

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Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹

1998

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A synthetic approach to racemic and enantiomerically pure, fused tricyclic 2-azetidinones and azetidines has been developed by using a Pauson-Khand (P-K) reaction on monocyclic enyne-beta-lactams as the key synthetic step. The access to cyclization precursors, monocyclic beta-lactams 1-7, was achieved by Staüdinger reaction of enyne imines 8 and 9 and D-glyceraldehyde imines 10 and (benzyloxy)- or phenoxyacetyl chlorides. Enyne imines 8 and 9 formed cis-2-azetidinones 1 and 2 having the required enyne moiety. cis-2-Azetidinones 11 were obtained as single diastereomers and transformed to enyne-2-azetidinones 3 and 5 by standard methodology. Alternatively, 4-formyl-2-azetidinones 14 were prepared by cyclization of p-anisyl glyoxal diimine and (benzyloxy)acetyl chloride and converted to racemic enyne-beta-lactams 4 and 6 by standard reactions. Enyne-2-azetidinones 1-7 were reacted with Co(2)(CO)(8) to quantitatively yield the corresponding alkyne-Co(2)(CO)(6) complexes. Reaction of such complexes with different promoters, especially heat and TMANO, formed tricyclic 2-azetidinones 15-19 with the ring system fused to the C3-C4 and C4-N1 lactam bonds. Yields were usually high, and the processes were highly diastereoselective. The exceptions were enyne-2-azetidinones 2 and 3a bearing N-propargyl moieties. These products decomposed to mixtures of unidentifiable products. Inhibition of the amide resonance was postulated as responsible for the failure of beta-lactams 2 and 3a to form tricyclic systems. In fact, the analogous enyne-azetidines 20a,b smoothly cyclized to form the corresponding tricyclic systems. This approach to tricyclic azetidines was extended to prepare different products. A new, unprecedented, N1-C2 bond breakage was also observed in the azetidine ring. The results described show that the P-K reaction is a suitable approach to tricyclic 2-azetidinones and azetidines. These are the first examples reported for a P-K reaction in with the enyne system is tethered to a strained heterocyclic four-membered ring.

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Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹

1998

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“…Natural and synthetic azetidinone derivatives occupy a central place among medicinally important compounds due to their diverse and interesting antibiotic activities [24][25][26][27]. Recent years have seen a resurgence of interest in the development of stereo-and enantio selective methodologies.…”

Section: Need Of New Antitubercular Drugsmentioning

confidence: 99%

Exploring Azatidinone Moiety: An Insight into its Anti-tubercular Potency

2021

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TB is becoming a worldwide problem and it was declared since 1993 by the World Health Organization (WHO), a global health emergency. The current problem of tuberculosis therapy is the emergence of multi-drug resistant (MDR) strains, caused by the improper use of antibiotics in chemotherapy of TB patients. Azatidinones, a β-lactam cyclic amide with four atoms in a ring, has been considered as a magic moiety (wonder nucleus) which possesses almost all types of biological activities. This diversity in the biological response profile has attracted the attention of many researchers to explore this skeleton to its multiple potential against several activities. Present article is sincere attempt to review chemistry, method of synthesis of azatidinones and to study azatidinones synthesized in last few years which have shown potent antitubercular activity.

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“…[1][2][3][4][5] Although the reaction has been discovered a hundred years ago, 4 it still attracts recent interest.…”

Section: Introductionmentioning

confidence: 99%

Pyrolysis of azetidinone derivatives: a versatile route towards electron-rich alkenes, C-1 allylation and/or homologation of aldehydes

et al. 2014

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Pyrolysis of b-lactams and b-thiolactams led essentially to stereoselective synthesis of the high energy electron-rich Z-alkenes. Extension of this methodology to the pyrolysis of 3-allyloxy derivatives gave a simple direct route to the synthetically important 4-pentenal. These pyrolytic transformations convert aldehydes to aryloxyalkenes (a protected homologation) and 4-pentenal (a C-1 allylation and homologation). The starting 3-aryloxy and 3-allyloxy-b-lactams were synthesized by the standard

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Azetidines, Azetines, and Azetes: Monocyclic

Cited by 51 publications

References 627 publications

Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹

Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹

Exploring Azatidinone Moiety: An Insight into its Anti-tubercular Potency

Pyrolysis of azetidinone derivatives: a versatile route towards electron-rich alkenes, C-1 allylation and/or homologation of aldehydes

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Azetidines, Azetines, and Azetes: Monocyclic

Cited by 51 publications

References 627 publications

Alkyne−Co2(CO)6 Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems,1

Alkyne−Co2(CO)6 Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems,1

Exploring Azatidinone Moiety: An Insight into its Anti-tubercular Potency

Pyrolysis of azetidinone derivatives: a versatile route towards electron-rich alkenes, C-1 allylation and/or homologation of aldehydes

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Product

Resources

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Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹

Alkyne−Co₂(CO)₆ Complexes in the Synthesis of Fused Tricyclic β-Lactam and Azetidine Systems^,¹