Diethylamine-catalyzed environmentally benign synthesis of 1-oxo-hexahydroxanthenes and bis-coumarins at ambient temperature

Kupwade, Ravindra V.; Pandit, Kapil S.; Desai, Uday V.; Kulkarni, Makarand A.; Wadgaonkar, Prakash P.

doi:10.1007/s11164-016-2464-4

Cited by 10 publications

(4 citation statements)

References 45 publications

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“…Consequently, a vast array of catalytic systems such as sulfamic acid 95 , diethylamine 96 , 2,4,6-trichloro-1,3,5-triazine 97 , p -TSA 98 , and catalyst-free 99 conditions have been discovered. Although the reported methodology offers several advantages, some of them suffer disadvantages like harsh reaction conditions, prolonged reaction time, high energy inputs, utilization of volatile organic solvents, non-recyclable catalytic system, low yield, and narrow substrate scopes.…”

Section: Resultsmentioning

confidence: 99%

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Borah

Swain

Patat

et al. 2023

Sci Rep

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Here, we have demonstrated a metal-free energy-efficient mechanochemical approach for expedient access to a diverse set of 2-amino-3-cyano-aryl/heteroaryl-4H-chromenes, tetrahydrospiro[chromene-3,4′-indoline], 2,2′-aryl/heteroarylmethylene-bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) as well as tetrahydro-1H-xanthen-1-one by employing the reactivity of 5,5-dimethylcyclohexane-1,3-dione/cyclohexane-1,3-dione with TsOH⋅H2O as Brønsted acid catalyst under water-assisted grinding conditions at ambient temperature. The ability to accomplish multiple C–C, C=C, C–O, and C–N bonds from readily available starting materials via a domino multicomponent strategy in the absence of metal-catalyst as well as volatile organic solvents with an immediate reduction in the cost of the transformation without necessitates complex operational procedures, features the significant highlights of this approach. The excellent yield of the products, broad functional group tolerances, easy set-up, column-free, scalable synthesis with ultralow catalyst loading, short reaction time, waste-free, ligand-free, and toxic-free, are other notable advantages of this approach. The greenness and sustainability of the protocol were also established by demonstrating several green metrics parameters.

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Section: Resultsmentioning

confidence: 99%

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Borah

Swain

Patat

et al. 2023

Sci Rep

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“…Logically, with the choice of an appropriate base, Knoevenagel-Michael Domino reactions could also be effected. Based upon this philosophy, recently we have reported the synthesis of 1-oxohexahydroxanthenes and bis-coumarins using diethylamine as the catalyst [18]. As the synthesis of bis-tetronic acids is also delineated to proceed by the KnoevenagelMichael Domino pathway, we planned to screen the suitability of a basic catalyst in the synthesis of bis-tetronic acids.…”

Section: Resultsmentioning

confidence: 99%

“…For instance, 1-oxo-hexahydroxanthenes ( Fig. 1A) results from the reaction between salicylaldehydes with two equivalents of cyclic-1,3-diones [14][15][16][17][18][19][20], while tetraketones ( Fig. 1B) result from the reaction between the same diketones with aromatic aldehydes, devoid of the ortho-hydroxyl group [21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Sulfamic acid-catalyzed, environmentally benign synthesis of bis-tetronic acids at ambient temperature

et al. 2016

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An enviro-economic protocol has been described for the synthesis of bistetronic acids by pseudo-three-component condensation between aldehydes/isatins and tetronic acid using sulfamic acid as a solid acid catalyst. Easy commercial availability of the catalyst at extremely low cost, excellent yields and avoidance of conventional purification procedures are the main merits of this energy efficient protocol. Graphical AbstractO O O Sulfamic acid EtOH, RT

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“…Biscoumarin derivatives have been synthesized through one pot cascade pseudo three component reaction of CÀ H activated acids and aromatic aldehydes under the catalysis of heterogeneous or homogeneous catalysts for instance various organic acids and bases, zeolites, metal catalysts, nanoparticles, Ionic liquids etc. Various catalytic systems used are tetrabutylammonium bromide (TBAB), [25] tetraethylammonium bromide (TEAB), [26] 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU), [27] 1,4diazabicyclo[2.2.2]octane (DABCO), [28] diethyl amine, [29] phosphosulphonic acid (PSA), [30] acetic acid, [31] piperidine, [32] poly(4vinylpyridine), [33] [PSebim][HSO 4 ], [34] some metal catalyst such as Ca(OTf) 2 , [35] Fe 3 O 4 , [36,37] tetrabutylammonium hexatungstate [TBA] 2 [W 6 O 19 ], [38] [MIM(CH 2 ) 4 SO 3 H][HSO 4 ], [39] tertamethylguanidium IL, [40] choline hydroxide, [41] Ceric ammonium nitrate, [42] amberlite, [43] montmorillonite, [44] humic acid [45] and many more. Khurana et al synthesized biscouamrins by using TBAB as a catalyst at high temperature (Scheme 1a).…”

Section: Introductionmentioning

confidence: 99%

Organo‐Catalytic Approach for Biscoumarin Synthesis via a Biomass‐Derived Sustainable Strategy

Garg

Reddy

2023

ChemistrySelect

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Biscouamrins are dimers of 4‐hydroxycoumarin formed by reaction of aldehydes and 4‐hydroxycoumarin. These were synthesized via one‐pot pseudo three component cascade reaction using sugar ionic liquid as an organo catalyst under green reaction conditions. Sugar derived from natural carbohydrates were used in the formulation of D‐ribose sugar ionic liquid (RSIL). In the formation of biscouamrins two reactions occurs i. e., Knoevenagel condensation and Michael addition reaction. Substituted aliphatic, aromatic and heterocyclic aldehydes were used for the synthesis of a variety of target biscouamrins products and developed protocol is scalable. Substitutions in the aryl ring of benzaldehyde showed very less or no effect on the reaction rate. The developed catalyst was shown to be recyclable five times without losing much of its efficiency.

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Diethylamine-catalyzed environmentally benign synthesis of 1-oxo-hexahydroxanthenes and bis-coumarins at ambient temperature

Cited by 10 publications

References 45 publications

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Brønsted acid catalyzed mechanochemical domino multicomponent reactions by employing liquid assisted grindstone chemistry

Sulfamic acid-catalyzed, environmentally benign synthesis of bis-tetronic acids at ambient temperature

Organo‐Catalytic Approach for Biscoumarin Synthesis via a Biomass‐Derived Sustainable Strategy

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