Consecutive isocyanide-based multicomponent reactions: synthesis of cyclic pentadepsipeptoids

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.10.101 ◽

2014 ◽

Vol 10 ◽

pp. 1017-1022 ◽

Cited By ~ 20

Author(s):

Angélica de Fátima S Barreto ◽

Otilie E Vercillo ◽

Ludger A Wessjohann ◽

Carlos Kleber Z Andrade

Keyword(s):

Multicomponent Reactions ◽

Synthetic Strategy ◽

Sansalvamide A

The synthesis of six cyclic depsipeptoids inspired by the natural depsipeptide sansalvamide A is described. An efficient and fast synthetic strategy was developed using a combination of consecutive isocyanide-based multicomponent reactions (Ugi and Passerini reactions). This methodology can be used to access a variety of cyclic oligodepsipeptoids.

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An Organocatalytic Newer Synthetic Strategy Toward the Access of Polyfunctionalized 4H-Pyrans via Multicomponent Reactions

Polycyclic Aromatic Compounds ◽

10.1080/10406638.2018.1454968 ◽

2018 ◽

Vol 40 (2) ◽

pp. 502-515 ◽

Cited By ~ 3

Author(s):

Rathinam Ramesh ◽

Jayaraj Jayamathi ◽

Chinnagoundar Karthika ◽

Jan Grzegorz Malecki ◽

Appaswami Lalitha

Keyword(s):

Multicomponent Reactions ◽

Synthetic Strategy

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Dibenzo-1,5-diazocine-2,6-dione, 2-Iminoindolin-3-one and N-(Carbamoylmethyl)-aminobenzoic Acid Ester from Aminobenzoic Acid by Multicomponent Reactions

Tetrahedron ◽

10.1016/s0040-4020(98)00718-2 ◽

1998 ◽

Vol 54 (31) ◽

pp. 11887-11898 ◽

Cited By ~ 1

Author(s):

B Ebert

Keyword(s):

Acid Ester ◽

Multicomponent Reactions ◽

Aminobenzoic Acid

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Multicomponent Reactions, Volume 2

10.1055/b-003-125831 ◽

2014 ◽

Cited By ~ 1

Keyword(s):

Multicomponent Reactions

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Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

10.26434/chemrxiv.6349253 ◽

2018 ◽

Author(s):

Erin Stache ◽

Alyssa B. Ertel ◽

Tomislav Rovis ◽

Abigail G. Doyle

Keyword(s):

Carboxylic Acids ◽

Functional Groups ◽

Single Step ◽

Direct Access ◽

Photoredox Catalysis ◽

Acyl Radical ◽

Synthetic Strategy ◽

Acyl Radicals ◽

Benzyl Radicals ◽

Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

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Synthesis of Conjugated Triynes via Alkyne Metathesis

10.26434/chemrxiv.8342534.v2 ◽

2019 ◽

Author(s):

Idriss Curbet ◽

Sophie Colombel-Rouen ◽

Romane Manguin ◽

Anthony Clermont ◽

Alexandre Quelhas ◽

...

Keyword(s):

Steric Hindrance ◽

High Selectivity ◽

Alkyne Metathesis ◽

Cross Metathesis ◽

Synthetic Strategy ◽

Sterically Hindered ◽

Site Selective

<div> <div> <div> <div> <p>The synthesis of conjugated triynes by molybdenum-catalyzed alkyne metathesis is reported. Strategic to the success of this approach is the utilization of sterically-hindered diynes that allowed for the site- selective alkyne metathesis to produce the desired con- jugated triyne products. The steric hindrance of alkyne moiety was found to be crucial in preventing the for- mation of diyne byproducts. This novel synthetic strategy was amenable to self- and cross-metathesis providing straightforward access to the corresponding symmetrical and dissymmetrical triynes with high selectivity. </p> </div> </div> </div> </div>

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Computationally Augmented Retrosynthesis: Total Synthesis of Paspaline A and Emindole PB

10.26434/chemrxiv.7322330.v1 ◽

2018 ◽

Author(s):

Timothy Newhouse ◽

Daria E. Kim ◽

Joshua E. Zweig

Keyword(s):

Chemical Synthesis ◽

Total Synthesis ◽

Small Molecules ◽

First Principles ◽

Quantum Chemical ◽

Computational Analysis ◽

Empirical Evaluation ◽

Synthetic Strategy ◽

Catalyzed Reactions ◽

Enzyme Catalyzed Reactions

The diverse molecular architectures of terpene natural products are assembled by exquisite enzyme-catalyzed reactions. Successful recapitulation of these transformations using chemical synthesis is hard to predict from first principles and therefore challenging to execute. A means of evaluating the feasibility of such chemical reactions would greatly enable the development of concise syntheses of complex small molecules. Herein, we report the computational analysis of the energetic favorability of a key bio-inspired transformation, which we use to inform our synthetic strategy. This approach was applied to synthesize two constituents of the historically challenging indole diterpenoid class, resulting in a concise route to (–)-paspaline A in 9 steps from commercially available materials and the first pathway to and structural confirmation of emindole PB in 13 steps. This work highlights how traditional retrosynthetic design can be augmented with quantum chemical calculations to reveal energetically feasible synthetic disconnections, minimizing time-consuming and expensive empirical evaluation.

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Synthesis of Elaborate Benzofuran-2-Carboxamide Derivatives Through a Combination of 8-Aminoquinoline Directed C–H Arylations and Transamidations

10.26434/chemrxiv.7925489.v1 ◽

2019 ◽

Author(s):

Michael Oschmann ◽

Linus Johansson Holm ◽

Oscar Verho

Keyword(s):

Small Molecule ◽

High Efficiency ◽

Synthetic Strategy ◽

Small Molecule Screening ◽

Physiological Properties ◽

Wide Range ◽

Directing Group ◽

Synthetic Sequence

Benzofurans are everywhere in nature and they have been extensively studied by medicinal chemists over the years because of their chemotherapeutic and physiological properties. Herein, we describe a strategy that can be used to access elaborate benzo-2-carboxamide derivatives, which involves a synthetic sequence of 8-aminoquinoline directed C–H arylations followed by transamidations. For the directed C–H arylations, Pd catalysis was used to install a wide range of aryl and heteroaryl substituents at the C3 position of the benzofuran scaffold in high efficiency. Directing group cleavage and further diversification of the C3-arylated benzofuran products were then achieved in a single synthetic operation through the utilization of a two-step transamidation protocol. By bocylating the 8-aminoquinoline amide moiety of these products, it proved possible to activate them towards aminolysis with different amine nucleophiles. Interestingly, this aminolysis reaction was found to proceed efficiently without the need of any additional catalyst or additive. Given the high efficiency and modularity of this synthetic strategy, it constitute a very attractive approach for generating structurally-diverse collections of benzofuran derivatives for small molecule screening.

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Reactivity of Barbituric, Thiobarbituric Acids and Their Related Analogues: Synthesis of Substituted and Heterocycles-based Pyrimidines

Current Organic Chemistry ◽

10.2174/1385272824999200608134859 ◽

2020 ◽

Vol 24 (14) ◽

pp. 1610-1642 ◽

Cited By ~ 1

Author(s):

Ahmed El-Mekabaty ◽

Hassan A. Etman ◽

Ahmed Mosbah ◽

Ahmed A. Fadda

Keyword(s):

Xanthine Oxidase ◽

Multicomponent Reactions ◽

Biological Activities ◽

Present Review ◽

Urease Inhibitors ◽

Effective Catalyst ◽

Inhibitory Activities ◽

Catalyst Reusability ◽

High Yields ◽

Nano Catalysts

Barbituric, thiobarbituric acids and their related analogs are reactive synthons for the synthesis of drugs and biologically, and pharmaceutically active pyrimidines. The present review aimed to summarize the recent advances in the synthesis of different alkylsubstituted, fused cycles, spiro-, and binary heterocycles incorporated pyrimidine skeleton based on barbituric derivatives. In this sequence, the eco-friendly techniques under catalytic conditions were used for the diverse types of multicomponent reactions under different conditions for the synthesis of various types of heterocycles. Nano-catalysts are efficient for the synthesis of these compounds in high yields and effective catalyst reusability. The compounds are potent antibacterial, cytotoxic, xanthine oxidase inhibitory activities, and attend as urease inhibitors. The projected mechanisms for the synthesis of pyranopyrimidines, benzochromenopyrimidines, chromeno-pyranopyrimidines, spiroxyindoles, oxospiro-tricyclic furopyrimidines, pyrimidine-based monoand bicyclic pyridines were discussed. The potent and diverse biological activities for instance, antioxidant, antibacterial, cytotoxic, and xanthine oxidase inhibitory activities, as well as urease inhibitors, are specified.

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