Highly Stereoselective Synthesis of Natural-Product-Like Hybrids by an Organocatalytic/Multicomponent Reaction Sequence

2015 ◽  
Vol 54 (26) ◽  
pp. 7621-7625 ◽  
Author(s):  
Radell Echemendía ◽  
Alexander F. de La Torre ◽  
Julia L. Monteiro ◽  
Michel Pila ◽  
Arlene G. Corrêa ◽  
...  
Keyword(s):  
Natural Product ◽  
Multicomponent Reaction ◽  
Stereoselective Synthesis ◽  
Reaction Sequence

Highly Stereoselective Synthesis of Natural-Product-Like Hybrids by an Organocatalytic/Multicomponent Reaction Sequence

2015 ◽  
Vol 127 (26) ◽  
pp. 7731-7735 ◽  
Author(s):  
Radell Echemendía ◽  
Alexander F. de La Torre ◽  
Julia L. Monteiro ◽  
Michel Pila ◽  
Arlene G. Corrêa ◽  
...  
Keyword(s):  
Natural Product ◽  
Multicomponent Reaction ◽  
Stereoselective Synthesis ◽  
Reaction Sequence

Stereoselective Synthesis of Pyroglutamate Natural Product Analogs from α- Aminoacids and their Anti-Cancer Evaluation

2013 ◽  
Vol 13 (10) ◽  
pp. 1514-1530 ◽  
Author(s):  
Srinivas Tekkam ◽  
Mohammad Alam ◽  
Matthew Just ◽  
Steven Berry ◽  
Joseph Johnson ◽  
...  
Keyword(s):  
Natural Product ◽  
Stereoselective Synthesis ◽  
Anti Cancer

scholarly journals Engineering P450 TamI as an Iterative Biocatalyst for Selective Late-Stage C-H Functionalization and Epoxidation of Tirandamycin Antibiotics

2021 ◽  
Author(s):  
Rosa V. Espinoza ◽  
Kersti Caddell Haatveit ◽  
S. Wald Grossman ◽  
Jin Yi Tan ◽  
Caylie A. McGlade ◽  
...  
Keyword(s):  
Natural Product ◽  
Late Stage ◽  
Md Simulations ◽  
Cascade Reactions ◽  
Direct Access ◽  
Tetramic Acid ◽  
Reaction Sequence ◽  
Substrate Reactivity ◽  
Continuous Oxidation

<div> <div> <div> <p>Iterative P450 enzymes are powerful biocatalysts for selective late-stage C-H oxidation of complex natural product scaffolds. These enzymes represent new tools for selectivity and cascade reactions, facilitating direct access to core structure diversification. Recently, we reported the structure of the multifunctional bacterial P450 TamI and elucidated the molecular basis of its substrate binding and strict reaction sequence at distinct carbon atoms of the substrate. Here, we report the design and characterization of a toolbox of TamI biocatalysts, generated by mutations at Leu101, Leu244 and/or Leu295, that alter the native selectivity, step sequence and number of reactions catalyzed, including the engineering of a variant capable of catalyzing a four-step oxidative cascade without the assistance of the flavoprotein and oxidative partner TamL. The tuned enzymes override inherent substrate reactivity enabling catalyst- controlled C-H functionalization and alkene epoxidation of the tetramic acid-containing natural product tirandamycin. Five new, bioactive tirandamycin derivatives (6-10) were generated through TamI-mediated enzymatic synthesis. Quantum mechanics calculations and MD simulations provide important insights on the basis of altered selectivity and underlying biocatalytic mechanisms for enhanced continuous oxidation of the iterative P450 TamI. </p> </div> </div> </div>

scholarly journals Concise Synthesis of Macrocycles by Multicomponent Reactions

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 1027-1038 ◽  
Author(s):  
Alexander Dömling ◽  
Eman Abdelraheem ◽  
Samad Khaksar
Keyword(s):  
Amino Acid ◽  
Multicomponent Reaction ◽  
Ring Opening ◽  
Multicomponent Reactions ◽  
Reaction Pathway ◽  
Ring Closure ◽  
Side Chains ◽  
Reaction Sequence ◽  
Cyclic Anhydride

A short reaction pathway was devised to synthesize a library of artificial 18–27-membered macrocycles. The five-step reaction sequence involves ring opening of a cyclic anhydride with a diamine, esterification, coupling with an amino acid isocyanide, saponification, and, finally, macro-ring closure using an Ugi or, alternatively, a Passerini multicomponent reaction. Three out of the five steps allow for the versatile introduction of linker elements, side chains, and substituents with aromatic, heteroaromatic, and aliphatic character. The versatile pathway is described for 15 different target macrocycles on a mmol scale. Artificial macrocycles have recently become of great interest due to their potential to bind to difficult post-genomic targets.

scholarly journals Enantio Selective Synthesis of New Phenylpropanoid: Isolated from Walsura trifoliata

2019 ◽  
Vol 31 (9) ◽  
pp. 2042-2046
Author(s):  
L.V. Ramana ◽  
M. Suri Appa Rao ◽  
K.M. Ch. Apparao ◽  
B. Nageswara Rao
Keyword(s):  
Medicinal Plant ◽  
Natural Product ◽  
Wittig Reaction ◽  
2D Nmr ◽  
Selective Synthesis ◽  
Reaction Sequence ◽  
Alternative Synthesis ◽  
Spectroscopic Evidence

A new phenylpropanoid containing flavon-3-ol has been isolated from the leaves of traditional medicinal plant, Walsura trifoliata. The structure of the compound was established on the basis of spectroscopic evidence [2D NMR, HREIMS] and by its alternative synthesis. The synthesis of this natural product was achieved from inexpensive and readily available starting materials of phloroglucinol dihydrate. Key reaction sequence includes Grubbs-II RCM reaction, Wittig reaction and sharpless dihydroxylation using AD-mix α.

Towards the Total Synthesis of Schisandrene: Stereoselective Synthesis of the Dibenzocyclooctadiene Lignan Core

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 908-911 ◽  
Author(s):  
K. Babu ◽  
Arramshetti Venkanna ◽  
Borra Poornima ◽  
Bandi Siva ◽  
B. Babu
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Asymmetric Reduction ◽  
Cross Coupling ◽  
Membered Ring ◽  
Stille Reaction ◽  
Reaction Sequence ◽  
Ring Closing Metathesis ◽  
Synthetic Strategy ◽  
First Time

A stereoselective synthesis of the dibenzocyclooctadiene ­lignan core of the natural product schisandrene is described. Starting from readily available gallic acid, the synthetic strategy involves Suzuki–Miyaura cross-coupling, Stille reaction, and ring-closing metathesis (RCM) in the reaction sequence. The required asymmetric center at C-7′ was established by an asymmetric reduction of a keto compound using the Corey–Bakshi–Shibata (CBS) catalyst. In our approach, the eight-membered ring was achieved by RCM for the first time.

Distillable ionic liquids for a new multicomponent reaction

2007 ◽  
Vol 79 (11) ◽  
pp. 1869-1877 ◽  
Author(s):  
Anthony E. Rosamilia ◽  
Christopher R. Strauss ◽  
Janet L. Scott
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Multicomponent Reaction ◽  
Reaction Medium ◽  
Building Blocks ◽  
Substituted Anilines ◽  
Reaction Sequence ◽  
Unsaturated Ketones ◽  
Direct Preparation

Adducts of dimethylamine and carbon dioxide form a "distillable ionic liquid" (DIMCARB) that may used as both a reaction medium and catalyst in the direct, atom-economical synthesis of useful synthetic building blocks, such as mono-condensed α,β-unsaturated ketones. The utilization of such building blocks in the synthesis of two new classes of versatile macrocycles, by a sequence of condensation reactions (H2O by-product), is described. Investigation into the mechanism of action of DIMCARB catalysis and observation of an aniline impurity arising from a competing reaction sequence led to development of a new multicomponent reaction for the direct preparation of 2- or 4-substituted anilines. Some of the macrocycles and anilines are, respectively, supramolecular host compounds and ligands for the preparation of metal complexes.

ChemInform Abstract: Concise Synthesis of Highly Substituted Benzo[a]quinolizines by a Multicomponent Reaction/Allylation/Heck Reaction Sequence.

ChemInform ◽  
2012 ◽  
Vol 43 (22) ◽  
pp. no-no
Author(s):  
Rene den Heeten ◽  
Leon J. P. van der Boon ◽  
Daniel L. J. Broere ◽  
Elwin Janssen ◽  
Frans J. J. de Kanter ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Heck Reaction ◽  
Reaction Sequence
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