scholarly journals Copper-catalysed alkylation of heterocyclic acceptors with organometallic reagents

2020 ◽  
Vol 16 ◽  
pp. 1006-1021
Author(s):  
Yafei Guo ◽  
Syuzanna R Harutyunyan
Keyword(s):  
Natural Products ◽  
Frequent Occurrence ◽  
Bioactive Molecules ◽  
Complex Molecules ◽  
Organometallic Reagents ◽  
Bond Forming ◽  
The Past ◽  
Bond Forming Reactions

Copper-catalysed asymmetric C–C bond-forming reactions using organometallic reagents have developed into a powerful tool for the synthesis of complex molecules with single or multiple stereogenic centres over the past decades. Among the various acceptors employed in such reactions, those with a heterocyclic core are of particular importance because of the frequent occurrence of heterocyclic scaffolds in the structures of chiral natural products and bioactive molecules. Hence, this review focuses on the progress made over the past 20 years for heterocyclic acceptors.

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

scholarly journals Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

2014 ◽  
Vol 10 ◽  
pp. 1848-1877 ◽  
Author(s):  
Thilo Focken ◽  
Stephen Hanessian
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Bioactive Compounds ◽  
Biologically Active ◽  
Bond Forming ◽  
Michael Additions ◽  
Bond Forming Reactions ◽  
Asymmetric Alkylations

A review of the synthesis of natural products and bioactive compounds adopting phosphonamide anion technology is presented highlighting the utility of phosphonamide reagents in stereocontrolled bond-forming reactions. Methodologies utilizing phosphonamide anions in asymmetric alkylations, Michael additions, olefinations, and cyclopropanations will be summarized, as well as an overview of the synthesis of the employed phosphonamide reagents.

scholarly journals The Enones as New Alkenyl Reagents via Ligand Promoted C–C Bonds Activation

2021 ◽  
Author(s):  
Hanyuan Li ◽  
Mei-Ling Wang ◽  
Yue-Wen Liu ◽  
Ling-Jun Li ◽  
Hui Xu ◽  
...  
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Functional Group ◽  
Bond Activation ◽  
Potential Utility ◽  
One Pot ◽  
Complex Molecules ◽  
The Past

Complementary to C–H bond activation, C–C bond activation has emerged over the past few years as an increasingly powerful tool to access and modify complex molecules. Ketones, owing to their versatility and availability, provide a significant platform for C–C bond activating reactions. Herein, we reported a <i>β</i>-carbon elimination strategy for alkene(sp<sup>2</sup>)–C(O) bonds to realize the olefination of unstrained enones via a vinyl palladium species, which delivers a series of conjugated polyene compounds. The protocol features broad substrate scope, excellent functional group tolerance and can be extended to dba (dibenzylideneacetone) substrates for olefination, alkynylation, arylation and amination, which demonstrates the generality of the approach and affords two valuable products in one pot. Furthermore, the late-stage functionalization of natural products (<i>β</i>-ionone and acetyl cedrene) and synthesis of natural products (piperine, lignarenone, novenone) highlight the potential utility of the reaction.

scholarly journals The Enones as New Alkenyl Reagents via Ligand Promoted C–C Bonds Activation

2021 ◽  
Author(s):  
Hanyuan Li ◽  
Mei-Ling Wang ◽  
Yue-Wen Liu ◽  
Ling-Jun Li ◽  
Hui Xu ◽  
...  
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Functional Group ◽  
Bond Activation ◽  
Potential Utility ◽  
One Pot ◽  
Complex Molecules ◽  
The Past

Complementary to C–H bond activation, C–C bond activation has emerged over the past few years as an increasingly powerful tool to access and modify complex molecules. Ketones, owing to their versatility and availability, provide a significant platform for C–C bond activating reactions. Herein, we reported a <i>β</i>-carbon elimination strategy for alkene(sp<sup>2</sup>)–C(O) bonds to realize the olefination of unstrained enones via a vinyl palladium species, which delivers a series of conjugated polyene compounds. The protocol features broad substrate scope, excellent functional group tolerance and can be extended to dba (dibenzylideneacetone) substrates for olefination, alkynylation, arylation and amination, which demonstrates the generality of the approach and affords two valuable products in one pot. Furthermore, the late-stage functionalization of natural products (<i>β</i>-ionone and acetyl cedrene) and synthesis of natural products (piperine, lignarenone, novenone) highlight the potential utility of the reaction.

Enantioselective Syntheses of Yohimbine Alkaloids: Proving Grounds for New Catalytic Transformations

Synthesis ◽  
2021 ◽  
Author(s):  
Karl A. Scheidt ◽  
Eric R Miller
Keyword(s):  
Natural Products ◽  
Chemical Synthesis ◽  
Total Synthesis ◽  
State Of The Art ◽  
The State ◽  
Catalytic Transformations ◽  
Bond Forming ◽  
The Past ◽  
Catalytic Asymmetric ◽  
Enantioselective Syntheses

The total synthesis of bioactive alkaloids is an enduring challenge and an indication of the state of the art of chemical synthesis. With the explosion of catalytic asymmetric methods over the past three decades, these compelling targets have been fertile proving grounds for enantioselective bond forming transformations. We summarize these activities herein both to highlight the power and versatility of these methods and to instill future inspiration for new syntheses of these privileged natural products.

The Application of C-H bond Functionalization in Total Syntheses of Indole Natural Products

2022 ◽  
Author(s):  
Dong-Xing Tan ◽  
Fu-She Han
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Total Syntheses ◽  
Bond Functionalization ◽  
Bond Forming ◽  
Bond Forming Reactions ◽  
Direct Functionalization

The direct functionalization of unactivated C–H bonds is a rapidly growing field in organic chemistry in recent years because of its indisputable advantages in bond forming reactions in terms of...

scholarly journals Concise total syntheses of (–)-jorunnamycin A and (–)-jorumycin enabled by asymmetric catalysis

Science ◽  
2018 ◽  
Vol 363 (6424) ◽  
pp. 270-275 ◽  
Author(s):  
Eric R. Welin ◽  
Aurapat Ngamnithiporn ◽  
Max Klatte ◽  
Guillaume Lapointe ◽  
Gerit M. Pototschnig ◽  
...  
Keyword(s):  
Natural Products ◽  
Asymmetric Catalysis ◽  
High Efficiency ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Polycyclic Compounds ◽  
Gram Negative ◽  
Total Syntheses ◽  
Bond Forming ◽  
The Past

The bis-tetrahydroisoquinoline (bis-THIQ) natural products have been studied intensively over the past four decades for their exceptionally potent anticancer activity, in addition to strong Gram-positive and Gram-negative antibiotic character. Synthetic strategies toward these complex polycyclic compounds have relied heavily on electrophilic aromatic chemistry, such as the Pictet–Spengler reaction, that mimics their biosynthetic pathways. Herein, we report an approach to two bis-THIQ natural products, jorunnamycin A and jorumycin, that instead harnesses the power of modern transition-metal catalysis for the three major bond-forming events and proceeds with high efficiency (15 and 16 steps, respectively). By breaking from biomimicry, this strategy allows for the preparation of a more diverse set of nonnatural analogs.

scholarly journals Lipids from Microalgae for Cosmetic Applications

Cosmetics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 52
Author(s):  
Maria De Luca ◽  
Ilaria Pappalardo ◽  
Antonina Rita Limongi ◽  
Emanuele Viviano ◽  
Rosa Paola Radice ◽  
...  
Keyword(s):  
Natural Products ◽  
Delivery System ◽  
Industrial Application ◽  
Lipid Classes ◽  
Bioactive Molecules ◽  
Microalgae Cultivation ◽  
The Past ◽  
Cosmetic Formulations ◽  
Microalgal Species ◽  
Microalgal Lipids

In recent years, there has been considerable interest in using microalgal lipids in the food, chemical, pharmaceutical, and cosmetic industries. Several microalgal species can accumulate appreciable lipid quantities and therefore are characterized as oleaginous. In cosmetic formulations, lipids and their derivatives are one of the main ingredients. Different lipid classes are great moisturizing, emollient, and softening agents, work as surfactants and emulsifiers, give consistence to products, are color and fragrance carriers, act as preservatives to maintain products integrity, and can be part of the molecules delivery system. In the past, chemicals have been widely used but today’s market and customers’ demands are oriented towards natural products. Microalgae are an extraordinary source of lipids and other many bioactive molecules. Scientists’ attention to microalgae cultivation for their industrial application is increasing. For the high costs associated, commercialization of microalgae and their products is still not very widespread. The possibility to use biomass for various industrial purposes could make microalgae more economically competitive.

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