Approaches towards the total synthesis of carolacton: synthesis of C1–C16 fragment

Reddy, Sheri Venkata; Kumar, K. Praveen; Ramakrishna, Kallaganti V. S.; Sharma, G. V. M.

doi:10.1016/j.tetlet.2015.03.002

Cited by 10 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the same reaction time, nitrobenzene also showed a relatively low conversion (around 43%), whereas acetonitrile led to a much higher conversion (75%), although still lower than the 100 % attained with DMF in hardly 1.5 h of reaction. These results are in good agreement with the literature when using other MOF materials [20], homogeneous catalysts [12] and different Ullman reactions [4,29,30]. The solvent has also an important effect on homogeneous Ullmann O-arylation reactions of phenol with aryl chlorides using copper bromide in the presence 1,10-phenantroline as ancillary ligand (L) [31].…”

Section: Influence Of Solventsupporting

confidence: 88%

Recyclable Cu-MOF-74 Catalyst for Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

Leo¹,

Orcajo²,

Briones³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract:The activity and cyclability of Cu-MOF-74 as catalyst was studied for the ligand-free C-O cross-coupling reaction of 4-nitrobenzaldehyde (NB) with phenol (Ph) to form 4-formyldiphenyl ether (FDE). Cu-MOF-74 is characterized by unsaturated copper sites in a highly porous metal-organic framework. The influence of solvent, reaction temperature, NB/Ph ratio, catalyst concentration and basic agent (type and concentration) were evaluated. High conversions were achieved at 120°C, 5 mol% of catalyst, NB/Ph ratio of 1:2, DMF as solvent and 1 equivalent of K2CO3 base. The activity of Cu-MOF-74 material was higher than other ligand-free copper catalytic systems tested in this study. This catalyst was easily separated and reused in five successive runs, achieving a remarkable performance without significant porous framework degradation. The leaching of copper species in the reaction medium was negligible. The O-arylation between NB and Ph took place only in the presence of Cu-MOF-74 material, being negligible without the solid catalyst.

show abstract

Section: Influence Of Solventsupporting

confidence: 88%

Recyclable Cu-MOF-74 Catalyst for Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

Leo¹,

Orcajo²,

Briones³

et al. 2017

Preprint

View full text Add to dashboard Cite

show abstract

“…Enantiomerically pure 2-substituted 3-hydroxycarboxylate esters are an important class of chiral building blocks widely used in organic synthesis. − For example, ( S )- and ( R )-methyl 3-hydroxy-2-methylpropanoate (i.e., Roche esters) are largely employed as precursors for the preparation of bioactive natural compounds and pharmaceuticals (e.g., discodermolide with potent antimitotic activity, epothilone analogue ZK-Epo (sagopilone), the ionophore antibiotic zincophorin, cytotoxic marine natural products auripyrones A and B, the depsipeptide stevastelin B3, and the antifungal polyketide soraphen A). − Other chiral 2-substituted 3-hydroxycarboxylate esters can be found in the preparation of peptide deformylase inhibitors (Figure ). , …”

Section: Introductionmentioning

confidence: 99%

Chemoenzymatic Hydroxymethylation of Carboxylic Acids by Tandem Stereodivergent Biocatalytic Aldol Reaction and Chemical Decarboxylation

Marín-Valls¹,

Hernández²,

Bolte

et al. 2019

ACS Catal.

View full text Add to dashboard Cite

Chiral 2-substituted 3-hydroxycarboxylic acid derivatives are valuable building blocks for the preparation of naturally occurring and synthetic biologically active molecules. Current methodologies for the preparation of these compounds are still limited for large-scale production due to the high costs, limited microbial strains, low yields, difficult downstream processing, and limited range of structures. We report an effective chemoenzymatic method for the synthesis of enantiomerically pure 2-substituted 3-hydroxycarboxylic esters. The strategy comprises: (i) a stereoselective aldol addition of 2-oxoacids to methanal catalyzed by two enantiocomplementary 2-oxoacid aldolases, (ii) oxidative decarboxylation, and (iii) esterification. Compounds with S-configuration were obtained in 69–80% isolated yields (94–99% ee), and the R enantiomers in 57–88% (88–98% ee), using a substrate concentration range of 0.1–1.0 M. The method developed offers a versatile alternative route to this important class of chiral building blocks and highlights the exciting opportunities available for using natural enzymes with minimal active site modification.

show abstract

“…Carolacton (Figure , (−) -1 ) is a myxobacterial natural product whose activity has been shown to promote cell membrane defects in S. mutans during biofilm growth when environmental pH rapidly decreases. − This specific and unique activity toward biofilm growth conditions has attracted a number of synthetic efforts, with three total syntheses and multiple analog campaigns disclosed. − In addition, several studies investigating these specific biofilm perturbation effects at low nanomolar concentrations have been reported.…”

mentioning

confidence: 99%

Synthetic Simplification of Carolacton Enables Chemical Genetic Studies in Streptococcus mutans

et al. 2019

View full text Add to dashboard Cite

Understanding the broader biological impact of carolacton, a macrolactone natural product, has been ongoing for the past decade. Multiple studies have shown connections to regulatory systems, acid tolerance mechanisms, biofilm formation, and recently folate dehydrogenase (FolD). Progress elucidating the cause of biofilm-specific activity in Streptococcus mutans has been limited due to low-throughput analyses of carolacton-treated cells. We disclose the discovery of a simplified carolacton-inspired analog that demonstrates inhibitory activity against S. mutans biofilm cells. This discovery permitted a proof of concept chemical genetic screen of S. mutans mutants identifying the carbon catabolite protein A signaling pathway as a putative target.

show abstract

Approaches towards the total synthesis of carolacton: synthesis of C1–C16 fragment

Cited by 10 publications

References 35 publications

Recyclable Cu-MOF-74 Catalyst for Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

Recyclable Cu-MOF-74 Catalyst for Ligand-Free O-Arylation Reaction of 4-Nitrobenzaldehyde and Phenol

Chemoenzymatic Hydroxymethylation of Carboxylic Acids by Tandem Stereodivergent Biocatalytic Aldol Reaction and Chemical Decarboxylation

Synthetic Simplification of Carolacton Enables Chemical Genetic Studies in Streptococcus mutans

Contact Info

Product

Resources

About