Three-component reaction of 3-(diethoxyphosphoryl)coumarin, enolizable ketones and primary amines: Simple, stereoselective synthesis of benzo[1,3]oxazocine skeletons

Deredas, Dariusz; Albrecht, Łukasz; Maniukiewicz, Waldemar; Wojciechowski, Jakub; Wolf, Wojciech M.; Paluch, Piotr; Janecki, Tomasz; Różalski, Marcin; Krajewska, Urszula; Janecka, Anna; Krawczyk, Henryk

doi:10.1039/c3ra40184g

Cited by 12 publications

(10 citation statements)

References 39 publications

(8 reference statements)

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“…The anti diastereoselectivity in the Michael addition step leading to the formation of the dihydrocoumarins 14 is in accord with the results of our previous studies 6 concerning the conjugate addition of secondary enamines, derived from cycloalkanones and benzylamine, to coumarin 7a. The reaction is proposed to occur via a synclinal acyclic transition state 13 in which the Si * face of the enolate approaches the Re * face of the coumarin (Scheme 4).…”

Section: Scheme 3 the Reaction Pathway In Methanolsupporting

confidence: 91%

“…5 In this letter we report the first examples of a tandem Michael-intramolecular HWE reaction of 2,5-hexanedione (8) with 3-(diethoxyphosphoryl)coumarins 7a-c in which the dione serves as a γ-oxoketone enolate equivalent. This approach expands greatly the scope of the conjugate addition involving coumarins 7 6 and provides a new and prac- Successful development of the reaction sequence required identification of bases that could be used for the enolate generation. After screening of a range of organic and inorganic bases, 1,5,7-triazabicyclo[4.4.…”

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confidence: 99%

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A Tandem Conjugate Addition–Intramolecular Horner–Wadsworth–Emmons Olefination Approach to the Synthesis of Cyclopentene[c]chroman-2-ones and Cyclopent-1-enecarboxylates

Deredas¹,

Huben²,

Maniukiewicz³

et al. 2013

Synlett

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A strategically new approach to cyclopentene[c]chroman-2-ones and cyclopent-1-enecarboxylates by tandem MichaelHorner-Wadsworth-Emmons reaction of 2,5-hexanedione with 3-(diethoxyphosphoryl)coumarins is described. The products were obtained as single diastereoisomers in high yields. The cyclopent-1-enecarboxylate moiety is present in many biologically active natural products. 1 Within this class of compounds the cyclopenta[c]tetrahydropyran-2-one ring system is incorporated in the reduced or modified form into natural products such as neonepetalactone (1) In recent years considerable research activity has been directed toward the synthesis of cyclopentene-fused chroman-2-ones. The synthetic strategies include [3+2] cycloaddition of allenoates with 3-alkoxycarbonylcoumarin, 3a intramolecular [3+2] cycloaddition of 2-styrenyl allenoates, 3b annulation of 3-acetylcoumarin with allenylboronic esters, 3c and [3+2] cycloaddition of 3-acetylcoumarin with cyclopropenone acetals. 3d Palladiumcatalyzed [3+2] cycloaddition of 2-(trimethylsilylmethyl)-allyl acetates with coumarins has been used to install a cyclopentane ring containing an exo-methylene group. 3e Despite its potential utility, the approach based on a Michael addition of homoenolate anion equivalents to α-dialkoxyphosphoryl-α,β-unsaturated lactones followed by an intramolecular Horner-Wadsworth-Emmons (HWE) reaction of the resulting 2-phosphono-6-oxoalkanoates has been exploited only rarely for the preparation of cyclopentene annulated γ-and δ-lactones. Minami et al. reported that the tandem Michael-intramolecular HWE reaction of diethyl 2-oxoalkylmalonates with α-phosphoryl-α,β-unsaturated-γ-lactones provided cyclopentenefused γ-lactones. 4a Bestmann et al. reported that Michael addition of [2-(1,3-dioxolan-2-yl)ethyl]magnesium bromide to 3-(diethoxyphosphoryl)coumarin followed by deprotection of the aldehyde group and an intramolecular HWE reaction led to cyclopentene-annulated chromanones. 4b In the course of our earlier studies we have reported that the above [3+2] annulation strategy could be extended for the preparation cyclopent-1-enecarboxylates from the corresponding tert-butyl (E)-2-(diethoxyphosphoryl)alk-2-enoates. 4c In spite of these advances, it is evident that methods to access cyclopentannulated lactones, particularly via conceptually different approaches are still of significant interest. It is worthy of note that 1,4-diketones are known to be potent homoenolate equivalents. 5a Surprisingly, a strategy for [3+2] cyclopentannulation that utilizes homoenolates generated from 1,4-diketones (γ-oxoketone enolates) as three-carbon fragments has not been exploited. 5 In this letter we report the first examples of a tandem Michael-intramolecular HWE reaction of 2,5-hexanedione (8) with 3-(diethoxyphosphoryl)coumarins 7a-c in which the dione serves as a γ-oxoketone enolate equivalent. This approach expands greatly the scope of the conjugate addition involving coumarins 7 6 and provides a new and prac-

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Section: Scheme 3 the Reaction Pathway In Methanolsupporting

confidence: 91%

mentioning

confidence: 99%

A Tandem Conjugate Addition–Intramolecular Horner–Wadsworth–Emmons Olefination Approach to the Synthesis of Cyclopentene[c]chroman-2-ones and Cyclopent-1-enecarboxylates

Deredas¹,

Huben²,

Maniukiewicz³

et al. 2013

Synlett

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“…X-ray data of [Pt(k 2 -dppmCl)Cl 2 ] complex were collected at 200 K in the Mo Kα radiation (0.71073 Å) on a Bruker Kappa Apex II diffractometer with graphite monochromated (λ= 0.71073 Å). The program APEX-Trak was utilized to data accumulation and SAINT for cell refinement and data reduction 12 . The structure was carry out by straight manners applying SIR97 13 and refined by smallest-squares procedures utilizing SHELXL-97 14 .…”

Section: Resultsmentioning

confidence: 99%

Crystal and Molecular Structure of Platinum(II) Complex with Bis(Diphenyl Phosphino)Methane

et al. 2019

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Platinum(II) complex consisting of the tertiarydiphosphine (dppm) ligand had been prepared from PdCl2 with one equiv. of dppm ligand to form [PtC2(dppmCl)] complex where as dppmCl is bis(dipheny1phosphino) chloromethene. Crystal was grown in dichloromethane by slow evaporation process and characterized by X-ray crystallography technic. The complex structure synthesized based upon the identification using X-ray Crystallography and FTIR was [PtC12(dppmCl)], the ligand dppm coordinated to the meta centre as bidentate chelating ligand and form square planar arrangement around Pt(II) metal centre. The bond distances of Pt-P1, Pt-P2, Pt- Cl1 and Pt-Cl2 are 2.217 (2), 2.217 (2), 2.3661 (19) and 2.3661 Aο respectively. The characterized results of Pt(II) complex using X-ray analysis illustrated that [PtC12(dppmCl)] Complex form monoclinic crystal with unit cell dimensions of a = 16.2034(5), b = 7.8274(2), and c = 19.2496 (6) Aο, with β = 98.918 (1)ο, Z=4, calculated density= 1.838 mg/m3, T= 200 k and space group C2/c

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“…Phosphorylated azaheterocycles were synthesized [57] by three-component reaction between 3-diethylphosphonocoumarin 1a with acetone, cyclopentanone or cyclohexanone and benzylamine. These compounds are promising precursors for the preparation of polycyclic δ-lactams possessing potential biological activity.…”

Section: Synthesis and Some Reactions Of Dialkyl 2-oxo-2h-1-benzopmentioning

confidence: 99%

Synthesis and Chemical Properties of 3-Phosphono-coumarins and 1,2-Benzoxaphosphorins as Precursors for Bioactive Compounds

Koleva

Petkova

2019

Molecules

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Coumarins are an important class of natural heterocyclic compounds that have attracted considerable synthetic and pharmacological interest due to their various biological activities. This review emphasizes on the synthetic methods for the preparation of dialkyl 2-oxo-2H-1-benzo- pyran-3-phosphonates and alkyl 1,2-benzoxaphosphorin-3-carboxylates. Their chemical properties as acceptors in conjugate addition reactions, [2+2] and [3+2] cycloaddition reactions are discussed.

show abstract

Three-component reaction of 3-(diethoxyphosphoryl)coumarin, enolizable ketones and primary amines: Simple, stereoselective synthesis of benzo[1,3]oxazocine skeletons

Cited by 12 publications

References 39 publications

A Tandem Conjugate Addition–Intramolecular Horner–Wadsworth–Emmons Olefination Approach to the Synthesis of Cyclopentene[c]chroman-2-ones and Cyclopent-1-enecarboxylates

A Tandem Conjugate Addition–Intramolecular Horner–Wadsworth–Emmons Olefination Approach to the Synthesis of Cyclopentene[c]chroman-2-ones and Cyclopent-1-enecarboxylates

Crystal and Molecular Structure of Platinum(II) Complex with Bis(Diphenyl Phosphino)Methane

Synthesis and Chemical Properties of 3-Phosphono-coumarins and 1,2-Benzoxaphosphorins as Precursors for Bioactive Compounds

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