An Unusual Michael Addition of 3,3-Dimethoxypropanenitrile to 2-Aryl Acrylates: A Convenient Route to 4-Unsubstituted 5,6-Dihydropyrido[2,3-<i>d</i>]pyrimidines

Berzosa, Xavier; Bellatriu, Xavier; Teixidó, Jordi; Borrell, José I.

doi:10.1021/jo902345r

Cited by 20 publications

(6 citation statements)

References 18 publications

(16 reference statements)

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“…The same aldehyde was taken through a Knoevenagel reaction, then esterification afforded alkenoate 25 b . The alkoxycarbonyl group was moved to the internal position in 25 c , prepared from the commercial phenylacetic acid that was esterified (99 %) and then condensed with formaldehyde (58 %) . Suzuki–Miyaura couplings between 8 and 25 a – c using procedure A, delivered electrocyclisation precursors in moderate to good yields (Scheme )…”

Section: Resultsmentioning

confidence: 99%

Modular Construction of Fluoroarenes from a New Difluorinated Building Block by Cross‐Coupling/Electrocyclisation/Dehydrofluorination Reactions

Percy

Emerson

Fyfe

et al. 2016

Chemistry A European J

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Palladium-catalysed coupling reactions based on a novel and easy-to-synthesise difluorinated organotrifluoroborate were used to assemble precursors to 6π-electrocyclisations of three different types. Electrocyclisations took place at temperatures between 90 and 240 °C, depending on the central component of the π-system; nonaromatic trienes were most reactive, but even systems that required the temporary dearomatisation of two arenyl subunits underwent electrocyclisation, albeit at elevated temperatures. Photochemical conditions were effective for these more demanding reactions. The package of methods delivered a structurally diverse set of fluorinated arenes, spanning a 20 kcal mol(-1) range of reactivity, by a flexible route.

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Section: Resultsmentioning

confidence: 99%

Modular Construction of Fluoroarenes from a New Difluorinated Building Block by Cross‐Coupling/Electrocyclisation/Dehydrofluorination Reactions

Percy

Emerson

Fyfe

et al. 2016

Chemistry A European J

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“…For the α‐methylenation of the ester 11a , several standard procedures were examined. These included: (a) paraformaldehyde, NaH, tetrahydrofuran (THF),8 (b) paraformaldehyde, K 2 CO 3 , tetrabutylammonium iodide, N , N ‐dimethylformamide (DMF),11 and (c) sodium hexamethyldisilazide (NaHMDS), CH 2 I 2 , THF 12. Unfortunately, none of these methylenation procedures were useful.…”

Section: Resultsmentioning

confidence: 99%

Total Synthesis of Neo‐Tanshinlactones through a Cascade Benzannulation‐Lactonization as the Key Step

Ghosh¹,

Karmakar²,

Mal³

2013

Eur J Org Chem

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The cascade annulation‐lactonization of phthalides with α‐carboxyfurylacrylates in the presence of lithium hexamethyldisilazide (LiHMDS) provides both convergent and semiconvergent regioselective syntheses of neo‐tanshinlactones in moderate yields. This methodology also offers an avenue for the direct syntheses of hitherto unreported 6‐alkoxycarbonyl‐substituted neo‐tanshinlactones and their heterocyclic analogues. A new synthesis of 4‐alkyl phthalides was developed on the basis of a combination of a Duff reaction and Fürstner cross‐coupling.

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“…We also achieved 4-unsubstituted 5,6-dihydropyrido[2,3-d]pyrimidines (55; R 4 = H) through the Michael addition of 2-aryl substituted acrylates (45; R 6 = aryl, R 5 = H) and 3,3-dimethoxypropanenitrile (52) which leads, depending on the reaction temperature (60 or −78 • C, respectively), to a 4-methoxymethylene substituted 4-cyanobutyric ester (54) or to a 4-dimethoxymethyl 4-cyanobutyric ester (53). These compounds are subsequently converted to the desired 4-unsubstituted compound (55; R 4 = H) upon treatment with a guanidine carbonate 49 under microwave irradiation [99]. We completed our approach to totally dehydrogenated pyrido[2,3-d]pyrimidin-7(8H)-ones (56)(57)(58) and (17; R 4 = H) by using several oxidation protocols [16].…”

Section: Synthesis From a Preformed Pyridonementioning

confidence: 99%

Pyrido[2,3-d]pyrimidin-7(8H)-ones: Synthesis and Biomedical Applications

et al. 2019

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Pyrido[2,3-d]pyrimidines (1) are a type of privileged heterocyclic scaffolds capable of providing ligands for several receptors in the body. Among such structures, our group and others have been particularly interested in pyrido[2,3-d]pyrimidine-7(8H)-ones (2) due to the similitude with nitrogen bases present in DNA and RNA. Currently there are more than 20,000 structures 2 described which correspond to around 2900 references (half of them being patents). Furthermore, the number of references containing compounds of general structure 2 have increased almost exponentially in the last 10 years. The present review covers the synthetic methods used for the synthesis of pyrido[2,3-d]pyrimidine-7(8H)-ones (2), both starting from a preformed pyrimidine ring or a pyridine ring, and the biomedical applications of such compounds.

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An Unusual Michael Addition of 3,3-Dimethoxypropanenitrile to 2-Aryl Acrylates: A Convenient Route to 4-Unsubstituted 5,6-Dihydropyrido[2,3-d]pyrimidines

Cited by 20 publications

References 18 publications

Modular Construction of Fluoroarenes from a New Difluorinated Building Block by Cross‐Coupling/Electrocyclisation/Dehydrofluorination Reactions

Modular Construction of Fluoroarenes from a New Difluorinated Building Block by Cross‐Coupling/Electrocyclisation/Dehydrofluorination Reactions

Total Synthesis of Neo‐Tanshinlactones through a Cascade Benzannulation‐Lactonization as the Key Step

Pyrido[2,3-d]pyrimidin-7(8H)-ones: Synthesis and Biomedical Applications

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