Facile synthesis of novel halogenated 4-pyrazolylspirocyclic-β-lactams: versatile heterocyclic synthons

Bhalla, Aman; Bari, S. S.; Bhalla, Jitender; Khullar, Sadhika; Mandal, Sanjay K.

doi:10.1016/j.tetlet.2016.05.047

Cited by 28 publications

(8 citation statements)

References 39 publications

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“…Racemic halogenated 4-pyrazolylspiro-β-lactams have also been prepared through halogen-mediated intrasulfenyl cyclization of cis-3-(prop-2'-ynyloxy)-4pyrazolyl-β-lactams 129 (Scheme 39). [56] Depending on the number of equivalents of Br 2 used, different halogenated spirocyclic β-lactams were obtained. These products result not only from de intrasulfenyl cyclization but also from polybromination, namely phenyl group electrophilic aromatic substitution reaction or double bond bromine electrophilic addition, and hydrobromic acid elimination events from the trihalogenated derivatives (e. g. 131 a).…”

Section: Halogen-mediated Cyclizationmentioning

confidence: 99%

“…The reaction of cis-3-(prop-2'-ynyloxy)-4-pyrazolyl-β-lactams 129 performed with iodine proved to be more chemoselective, as monoiodinated 4-pyrazolylspirocyclic-β-lactams 133 were obtained efficiently as sole products (Scheme 40). [56] Bhalla et al used a similar method for the synthesis of 4-halomethyl-1,3-oxaselenolane substituted spiro-βlactams 135 via intraselenyl cyclization of cis-3allyloxy-3-benzylselenoazetidin-2-one 134 mediated by halogens, namely I 2 and Br 2 (Scheme 41). [57] Both halogens gave similar yields (68-70% yield).…”

Section: Halogen-mediated Cyclizationmentioning

confidence: 99%

“…The reaction of cis ‐3‐(prop‐2’‐ynyloxy)‐4‐pyrazolyl‐β‐lactams 129 performed with iodine proved to be more chemoselective, as monoiodinated 4‐pyrazolylspirocyclic‐β‐lactams 133 were obtained efficiently as sole products (Scheme 40). [56] …”

Section: Spiro‐β‐lactamsmentioning

confidence: 99%

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Recent Advances in the Synthesis of Spiro‐β‐Lactams and Spiro‐δ‐Lactams

Alves

Soares

et al. 2021

Adv Synth Catal

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Spirocyclic molecules are widely recognized for their complex three-dimensional features and structural rigidity. Among this class of molecules, the spiro-lactams subclass stands out, being extensively explored due to its bioactivity and utility in a variety of scientific fields such as drug design and organic synthesis. Given the recognition of spirocyclic lactams' broad potential, several efforts have been engaged on the pursuit of new synthetic strategies towards these molecules. The present review gathers advances on the synthesis of both spiroβ-lactams (spiroazetidin-2-ones) and spiro-δ-lactams (spiropiperidon-2-ones) reported since 2015. The work is divided into two distinct parts, each one dedicated to one of these types of spiro-lactam, with the approach used for building the spirocyclic system being extensively discussed, according to the meth-

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Section: Halogen-mediated Cyclizationmentioning

confidence: 99%

Section: Halogen-mediated Cyclizationmentioning

confidence: 99%

See 1 more Smart Citation

Recent Advances in the Synthesis of Spiro‐β‐Lactams and Spiro‐δ‐Lactams

Alves

Soares

et al. 2021

Adv Synth Catal

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“…Halocyclization of seleno-or thio-substituted β-lactams containing a carbon-carbon multiple bond concerns one of the pioneering methods for synthesis of halogenated 4-pyrazolyl spirocyclic-β-lactams. [79][80][81] Bhalla has recently reported on the synthesis of halogenated 4-pyrazolyl spirocyclic-β-lactams 107-110 via halogen-mediated intrasulfenyl cyclization of cis-3-propynyloxy-4-pyrazolyl-β-lactams 106 (Scheme 32). The effect of halogenating reagents and selectivity on the formation of the product has been carefully considered.…”

Section: Scheme 31mentioning

confidence: 99%

An update on the synthesis and reactivity of spiro-fused β-lactams

Thi¹,

D’hooghe²

2019

Arkivoc

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β-Lactam ring-containing compounds play a pivotal role in drug design and synthetic chemistry. Spirocyclic βlactams, representing an important β-lactam subclass, have recently attracted considerable interest with respect to new synthetic methodologies and pharmacological applications. The aim of this manuscript is to review the recent progress made in this field, covering publications disseminated between 2011 to 2018 concerning the synthesis and application of spirocyclic β-lactams. In the first part, new approaches to the synthesis of spirocyclic β-lactams, including Staudinger synthesis, cyclization and transformation reactions, will be presented. The reactivity and biological properties of spiro-β-lactams will be described in the second and third part, respectively.

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“…Till now, our research group has been engaged in the synthesis of selenoalkanoic acids useful as β‐lactam precursors , novel 3‐thio/seleno‐β‐lactams and their Lewis acid mediated functionalization , stereoselective synthesis of cis ‐ and trans ‐3‐alkoxy‐β‐lactams , spirocyclic‐β‐lactams , ( Z )‐ and ( E )‐3‐allylidene‐β‐lactams , 3‐keto‐β‐lactams , bicyclic‐β‐lactams , and 4‐pyrazolyl β‐lactams . Herein, we report the synthesis of novel pyrimidine/pyrazole linked β‐lactams using a facile and efficient methodology.…”

Section: Introductionmentioning

confidence: 99%

Pyrimidine and Pyrazole Linked Azetidin‐2‐ones: Entry to Novel Class of β‐Lactam Heterocycles

Bhalla

Bari

Rathee

et al. 2017

Journal of Heterocyclic Chem

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A novel series of pyrimidine/pyrazole linked β-lactams have been synthesized in excellent yields using a simple and efficient methodology involving conjunction of different heterocyclic substrates. All the new products were characterized on the basis of various spectroscopic techniques viz. FT-IR, 1 H NMR, 13 C NMR, elemental analysis (CHN), 1 H-1 H correlation spectroscopy ( 1 H-1 H COSY) and mass spectrometry (EIMS) in representative cases. Furthermore, theoretical calculations have also been performed on representative compounds and the results were compared with Cefuroxime axetil (a broad spectrum antibacterial agent). The phenomenon of tautomerism was also observed which was confirmed by different NMR experiments (D 2 O exchange study and 1 H-1 H correlation spectroscopy).

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Facile synthesis of novel halogenated 4-pyrazolylspirocyclic-β-lactams: versatile heterocyclic synthons

Cited by 28 publications

References 39 publications

Recent Advances in the Synthesis of Spiro‐β‐Lactams and Spiro‐δ‐Lactams

Recent Advances in the Synthesis of Spiro‐β‐Lactams and Spiro‐δ‐Lactams

An update on the synthesis and reactivity of spiro-fused β-lactams

Pyrimidine and Pyrazole Linked Azetidin‐2‐ones: Entry to Novel Class of β‐Lactam Heterocycles

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