Regio- and stereoselective oxidation of flavan-3-ol- 4-arylflavan-3-ol- and biflavanoid derivatives with 2,3-dichloro-56-dicyano-1,4-benzoquinone (DDQ)

Steenkamp, Jacobus A.; Mouton, C. H. L.; Ferreira, Daneel

doi:10.1016/s0040-4020(01)82322-x

Cited by 26 publications

(16 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was unambiguously resolved by NMR experiments coupled with molecular modelling19 which showed that both catechin and epicatechin gave the same S diastereomers independently of the stereochemistry of the contiguous C3 carbon atom (Scheme ). These results are in agreement with the initial suggestion that the approach of DDQ could be controlled by the stereochemistry at the C2 atom and occurs on the lower face of the aromatic ring A in order to avoid interactions with the axial H2 atom 18e. Finally, the last step of the precursor synthesis involves the regioselective aromatic halogenation of the C8 position to circumvent an uncontrolled oligomerization process during the coupling reaction.…”

Section: Resultssupporting

confidence: 89%

An Improved Synthesis of Procyanidin Dimers: Regio‐ and Stereocontrol of the Interflavan Bond

Tarascou¹,

Barathieu²,

André³

et al. 2006

Eur J Org Chem

View full text Add to dashboard Cite

A direct and general synthesis of procyanidin dimers B1, B2, B3 and B4 (10a-d) is presented. The approach is based on the stoichiometric coupling of two protected monomeric units (the nucleophilic 2a-b and electrophilic 4a-b partners) and deals with the regio-and stereocontrol of the C4-C8 interflavan bond as well as the control of the degree of oligomerization. The synthesis involves a five-step pathway starting from

show abstract

Section: Resultssupporting

confidence: 89%

An Improved Synthesis of Procyanidin Dimers: Regio‐ and Stereocontrol of the Interflavan Bond

Tarascou¹,

Barathieu²,

André³

et al. 2006

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…The resulting persilylated catechin derivative was then treated with DDQ in the presence of allyl alcohol to furnish allyl ether 3 b in 85 % yield as a single stereoisomer, in agreement with previous related works (Scheme 2). [14b,d,e] The nucleophilic substitution reaction of 3 b with octane‐1,8‐dithiol was promoted by the use of the Lewis acid BF 3 ⋅ Et 2 O [14b,d] at low temperature in CH 2 Cl 2 to cleanly afford the thioether 3 c . The stereochemistry at its C3 and C4 centers was confirmed to be cis by 1 H NMR analysis, again in agreement with previous related works [14b,d] .…”

Section: Resultsmentioning

confidence: 99%

Real‐Time Analysis of Polyphenol–Protein Interactions by Surface Plasmon Resonance Using Surface‐Bound Polyphenols

López

Tran

Viault

et al. 2021

Chemistry A European J

View full text Add to dashboard Cite

As election of bioactive polyphenols of different structural classes, such as the ellagitannins vescalagin and vescalin, the flavanoidsc atechin, epicatechin,e pigallocatechin gallate (EGCG), and procyanidin B2, and the stilbenoids resveratrol and piceatannol, were chemically modified to bear ab iotin unit for enabling their immobilization on streptavidin-coateds ensor chips. These sensorc hips were used to evaluate in real time by surfacep lasmon resonance(SPR) the interactionso fthree different surface-bound polyphenolic ligandsp er sensorc hip with variousp rotein analytes, including human DNA topoisomerase IIa,f lavonoid leucoanthocyanidin dioxygenase, B-cell lymphoma 2a poptosis regulator protein,a nd bovine serum albumin. The types and levels of SPR responses unveiled major differences in the association,o rl ack thereof,a nd dissociation between ag iven protein analyte and different polyphenolic ligands. Thus,t his multi-analysis SPR technique is av aluablem ethodology to rapidly screena nd qualitatively compare various polyphenol-protein interactions.

show abstract

“…96 ). 58 If this complex remains closely associated, ethoxyethanol would then attack from the bottom face, thus leading to α-ether 95 as the major diastereomer.…”

Section: Third Generation Strategymentioning

confidence: 99%

“…Conformational analysis of 94 indicates that the seven-membered ring protrudes from the bottom face of the molecule, suggesting that C–O bond formation appears to proceed with contrasteric selectivity. The observed stereochemical outcome might result from an overall double inversion process that proceeds by initial association of DDQ from the less hindered top face of 94 to form a tightly bound charge-transfer complex (i.e., 96 ) . If this complex remains closely associated, ethoxyethanol would then attack from the bottom face, thus leading to α-ether 95 as the major diastereomer.…”

Section: Third-generation Strategymentioning

confidence: 99%

“…The observed stereochemical outcome might result from an overall double inversion process that proceeds by initial association of DDQ from the less hindered top face of 94 to form a tightly bound charge-transfer complex (i.e., 96). 58 If this complex remains closely associated, ethoxyethanol would then attack from the bottom face, thus leading to α-ether 95 as the major diastereomer.…”

Section: ■ Third-generation Strategymentioning

confidence: 99%

See 1 more Smart Citation

Evolution of a Strategy for the Enantioselective Total Synthesis of (+)-Psiguadial B

et al. 2018

View full text Add to dashboard Cite

(+)-Psiguadial B is a diformyl phloroglucinol meroterpenoid that exhibits anti-proliferative activity against the HepG2 human hepatoma cancer cell line. This full account details the evolution of a strategy that culminated in the first enantioselective total synthesis of (+)-psiguadial B. A key feature of the synthesis is the construction of the trans-cyclobutane motif by a Wolff rearrangement with in situ catalytic, asymmetric trapping of the ketene. An investigation of the substrate scope of this method to prepare enantioenriched 8-aminoquinolinamides is disclosed. Three routes toward (+)-psiguadial B were evaluated that featured the following key steps: 1) an ortho-quinone methide hetero–Diels–Alder cycloaddition to prepare the chroman framework; 2) a Prins cyclization to form the bridging bicyclo[4.3.1]decane system, and 3) a modified Norrish–Yang cyclization to generate the chroman. Ultimately, the successful strategy employed a ring-closing metathesis to form the seven-membered ring and an intramolecular O-arylation reaction to complete the polycyclic framework of the natural product.

show abstract

Regio- and stereoselective oxidation of flavan-3-ol- 4-arylflavan-3-ol- and biflavanoid derivatives with 2,3-dichloro-56-dicyano-1,4-benzoquinone (DDQ)

Cited by 26 publications

References 6 publications

An Improved Synthesis of Procyanidin Dimers: Regio‐ and Stereocontrol of the Interflavan Bond

An Improved Synthesis of Procyanidin Dimers: Regio‐ and Stereocontrol of the Interflavan Bond

Real‐Time Analysis of Polyphenol–Protein Interactions by Surface Plasmon Resonance Using Surface‐Bound Polyphenols

Evolution of a Strategy for the Enantioselective Total Synthesis of (+)-Psiguadial B

Contact Info

Product

Resources

About