scholarly journals Rh(III)-Catalyzed C–H Bond Activation for the Construction of Heterocycles with sp3-Carbon Centers

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 823 ◽  
Author(s):  
Run Wang ◽  
Xiong Xie ◽  
Hong Liu ◽  
Yu Zhou
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Bond Activation ◽  
Short Review ◽  
Biological Molecules ◽  
Reaction Conditions ◽  
Reaction Efficiency ◽  
Carbon Centers ◽  
High Reaction ◽  
Privileged Structures

Rh(III)-catalyzed C–H activation features mild reaction conditions, good functional group tolerance, high reaction efficiency, and regioselectivity. Recently, it has attracted tremendous attention and has been employed to synthesize various heterocycles, such as indoles, isoquinolines, isoquinolones, pyrroles, pyridines, and polyheterocycles, which are important privileged structures in biological molecules, natural products, and agrochemicals. In this short review, we attempt to present an overview of recent advances in Rh(III)-mediated C–H bond activation to generate diverse heterocyclic scaffolds with sp3 carbon centers.

scholarly journals Tyrosine and Drug-like Late-stage Benzylic Functionalization via Photoredox Catalysis

2020 ◽  
Author(s):  
Tobias Brandhofer ◽  
Volker Derdau ◽  
María Mendez ◽  
Christoph Pöverlein ◽  
Olga Garcia Mancheno
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Late Stage ◽  
Medicinal Chemistry ◽  
Functional Group ◽  
Reaction Conditions ◽  
Site Selectivity ◽  
Wide Range ◽  
High Yields ◽  
Therapeutic Compounds

Abstract Visible light mediated late-stage functionalization is a rising field in synthetic and medicinal chemistry, allowing the fast and diversified modification of valuable, potentially therapeutic compounds such as peptides. However, there are relatively few mild methodologies for the C(sp3)-H functionalization of complex peptides. Herein, we report a visible light mediated photocatalytic protocol for the benzylic C-H modification of tyrosine and related C-H bonds. The embraced radical-cation/deprotonation strategy enables an incorporation of a wide range of valuable functional groups in high yields and chemoselectivity. The mild reaction conditions, site-selectivity and high functional group tolerance was highlighted by the functionalization of complex peptides, drugs and natural products, providing a promising synthetic platform in medicinal chemistry.

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.

Biosynthesis of Flavour-Active Esters via Lipase-Mediated Reactions and Mechanisms

2014 ◽  
Vol 67 (10) ◽  
pp. 1373 ◽  
Author(s):  
Jingcan Sun ◽  
Liang Wei Wilson Lee ◽  
Shao Quan Liu
Keyword(s):  
Natural Products ◽  
Industrial Production ◽  
Large Scale ◽  
Short Review ◽  
Enzyme Properties ◽  
Reaction Conditions ◽  
Active Esters ◽  
Catalyzed Reactions

Flavour active esters belong to one group of fine aroma chemicals that impart desirable fruity flavour notes and are widely applied in the flavour and fragrance industry. Due to the increasing consumer concern about health, natural products are attracting more attention than chemically synthesized substances. The biosynthesis of flavour-active esters via lipase-catalyzed reactions is one of the most important biotechnological methods for natural flavour generation. To proceed with the industrial production of esters on a large scale, it is critical to understand the enzyme properties and behaviours under different reaction conditions. In this short review, the lipase-catalyzed reactions in various systems and their mechanisms for synthesis of the esters are summarized and discussed.

Rhodium(iii)-catalyzed C–H allylation of electron-deficient alkenes with allyl acetates

2015 ◽  
Vol 51 (2) ◽  
pp. 342-345 ◽  
Author(s):  
Chao Feng ◽  
Daming Feng ◽  
Teck-Peng Loh
Keyword(s):  
Functional Group ◽  
Synthetic Pathway ◽  
Reaction Efficiency ◽  
High Reaction ◽  
Directing Group ◽  
Weakly Coordinating

Rhodium-catalyzed C–H allylation of acrylamide derivatives with various allyl acetates was reported. The use of weakly coordinating directing group resulted in high reaction efficiency and excellent γ-selectivity. This reaction displays broad functional group tolerance, which opens a new synthetic pathway for the access of functionalized 1,4-diene skeletons.

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

Modern Organic Synthesis in the Laboratory

2008 ◽  
Author(s):  
Jie Jack Li ◽  
Chris Limberakis ◽  
Derek A. Pflum
Keyword(s):  
Organic Chemistry ◽  
Graduate Students ◽  
Organic Synthesis ◽  
Functional Group ◽  
Bond Formation ◽  
Reaction Conditions ◽  
Carbon Bond ◽  
Oxidation Reduction ◽  
Carbon Carbon Bond ◽  
Daunting Task

Searching for reaction in organic synthesis has been made much easier in the current age of computer databases. However, the dilemma now is which procedure one selects among the ocean of choices. Especially for novices in the laboratory, it becomes a daunting task to decide what reaction conditions to experiment with first in order to have the best chance of success. This collection intends to serve as an "older and wiser lab-mate" one could have by compiling many of the most commonly used experimental procedures in organic synthesis. With chapters that cover such topics as functional group manipulations, oxidation, reduction, and carbon-carbon bond formation, Modern Organic Synthesis in the Laboratory will be useful for both graduate students and professors in organic chemistry and medicinal chemists in the pharmaceutical and agrochemical industries.

Nickel-Catalyzed Multicomponent Coupling Reaction of Alkyl Halides, Isocyanides and H2O: An Expedient Way to Access Alkyl Amides

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3466-3472
Author(s):  
Yunkui Liu ◽  
Bingwei Zhou ◽  
Qiao Li ◽  
Hongwei Jin
Keyword(s):  
Functional Group ◽  
Coupling Reaction ◽  
Alkyl Halides ◽  
Previous Literature ◽  
Catalytic Cycle ◽  
Reaction Conditions ◽  
Multicomponent Coupling ◽  
Easy Operation

We herein describe a Ni-catalyzed multicomponent coupling reaction of alkyl halides, isocyanides, and H2O to access alkyl amides. Bench-stable NiCl2(dppp) is competent to initiate this transformation under mild reaction conditions, thus allowing easy operation and adding practical value. Substrate scope studies revealed a broad functional group tolerance and generality of primary and secondary alkyl halides in this protocol. A plausible catalytic cycle via a SET process is proposed based on preliminary experiments and previous literature.

Rh(III)-Catalyzed Olefination and Alkylation of Arenes with Maleimides: A Tunable Strategy for C(sp2)–H Functionalization

Synthesis ◽  
2021 ◽  
Author(s):  
Hongji Li ◽  
Wenjie Zhang ◽  
Xueyan Liu ◽  
Zhenfeng Tian
Keyword(s):  
Room Temperature ◽  
Functional Group ◽  
Reaction Conditions ◽  
Bond Functionalization ◽  
Alkylation Process ◽  
Coupling Partner

AbstractWe herein report a new nitrogen-directed Rh(III)-catalyzed C(sp2)–H bond functionalization of N-nitrosoanilines and azoxybenzenes with maleimides as a coupling partner, in which the olefination/alkylation process can be finely controlled at room temperature by variation of the reaction conditions. This method shows excellent functional group tolerance, and presents a mild access to the resulting olefination/alkylation products in moderate to good yields.

Sulfonyl Radical Triggered Selective Iodosulfonylation and Bicycli-zations of 1,6-Dienes

2021 ◽  
Author(s):  
Shi-Ping Wu ◽  
Dong-Kai Wang ◽  
Qing-Qing Kang ◽  
Guo-Ping Ge ◽  
Hongxing Zheng ◽  
...  
Keyword(s):  
Functional Group ◽  
High Selectivity ◽  
Reaction Conditions ◽  
First Time

A novel sulfonyl radical triggered selective iodosulfonylation and bicyclizations of 1,6-dienes has been described for the first time. High selectivity and efficiency, mild reaction conditions, excellent functional group compatibility, and...

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