Synthesis and Rotational Isomerism of 1-Substituted Methyl (<i>S</i>)-[5-(2-Nitrophenyl)-1<i>H</i>-pyrazole-4-carbonyl]alaninates

Šenica, Luka; Stopar, Karmen; Friedrich, Miha; Grošelj, Uroš; Plavec, Janez; Počkaj, Marta; Podlipnik, Črtomir; Štefane, Bogdan; Svete, Jurij

doi:10.1021/acs.joc.5b02467

Cited by 6 publications

(1 citation statement)

References 34 publications

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“…In the context of our ongoing work on the synthesis of chiral heterocycles with emphasis on pyrazole 33,34 and pyrazolidinone derivatives, 31,32 we reported the synthesis of tetrahydropyrazolo [1,5-c]pyrimidine-2,7-diones as the first representatives of a novel saturated heterocyclic system, 35,36 followed by preparation of closely related tetrahydropyrazolo [1,5-c]pyrimidine-3-carboxamides 37 and tetrahydro-1H-imidazo [1,5-b]pyrazole-2,6-diones. 38 In ex-…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Novel 3D-Rich α-Amino Acid-Derived 3-Pyrazolidinones

Glavač¹,

Dahmann²,

Požgan³

et al. 2017

ACSi

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Synthetic approaches towards novel 3-pyrazolidinone derivatives functionalized at positions N(1) and/or C(5) were studied. 5-Aminoalkyl-3-pyrazolidinones were prepared in four steps from N-protected glycines via Masamune-Claisen homologation, reduction, O-mesylation, and cyclisation with a hydrazine derivative. The free amines were prepared by acidolytic deprotection. Title compound was also prepared by 'ring switching' transformation of N-Boc-pyrrolin-2(5H)-one with hydrazine hydrate. Hydrogenolytic deprotection of 5-(N-alkyl-N-Cbz-aminomethyl)pyrazolidine-3-ones followed by cyclisation with 1,1'-carbonyldiimidazole (CDI) gave two novel representatives of perhydroimidazo [1,5-b] pyrazole, which is an almost unexplored heterocyclic system. Amidation of 3-oxopyrazolidine-5-carboxylic acid gave the corresponding carboxamides in moderate yields. Diastereomeric non-racemic carboxamides obtained from (S)-AlaOMe and (S)-ProOMe were separated by MPLC.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Novel 3D-Rich α-Amino Acid-Derived 3-Pyrazolidinones

Glavač¹,

Dahmann²,

Požgan³

et al. 2017

ACSi

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Catalytic Asymmetric Formal [3+2] Cycloaddition of 2‐Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ‐Lactams

Espinosa

Blay

Cardona

et al. 2017

Chemistry A European J

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Unlike their isocyano and isothiocyanato analogues, isocyanato esters remain almost unexplored as formal 1,3-dipoles in asymmetric catalytic reactions. The first asymmetric formal [3+2] cycloaddition involving isocyanato esters and electrophilic alkenes is reported. Diisopropyl 2-isocyanatomalonate reacts with α,β-unsaturated N-(o-anisidyl) imines in the presence of a Mg(OTf) -BOX complex to give highly substituted chiral pyrrolidinones featuring a conjugate exocyclic double bond with excellent yields and enantiomeric excesses up to 99 %. Several transformations of the resulting heterocycles, including the synthesis of a pyroglutamic acid derivative, have been carried out.

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Pyrazoles

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2022

Comprehensive Heterocyclic Chemistry IV

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Synthesis and Rotational Isomerism of 1-Substituted Methyl (S)-[5-(2-Nitrophenyl)-1H-pyrazole-4-carbonyl]alaninates

Cited by 6 publications

References 34 publications

Synthesis of Novel 3D-Rich α-Amino Acid-Derived 3-Pyrazolidinones

Synthesis of Novel 3D-Rich α-Amino Acid-Derived 3-Pyrazolidinones

Catalytic Asymmetric Formal [3+2] Cycloaddition of 2‐Isocyanatomalonate Esters and Unsaturated Imines: Synthesis of Highly Substituted Chiral γ‐Lactams

Pyrazoles

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