Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds

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Aryl-aryl bond formation one century after the discovery of the Ullmann reaction.

The direct functionalization of C-H bonds in organic compounds has recently emerged as a powerful and ideal method for the formation of carbon-carbon and carbon-heteroatom bonds. This Review provides an overview of C-H bond functionalization strategies for the rapid synthesis of biologically active compounds such as natural products and pharmaceutical targets.

C-H bond functionalization: emerging synthetic tools for natural products and pharmaceuticals

This Review covers recent progress on near-infrared fluorescence imaging for preclinical animal studies and clinical diagnostics and interventions.

Near-infrared fluorophores for biomedical imaging

Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aube rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

Mechanochemistry involves the application of mechanical energy to achieve chemical transformations. Since it is usually performed in solid state at room temperature, mechanochemistry is regarded as one of the pathways toward more sustainable synthetic chemistry. Furthermore, by working under solvent-free conditions, reagents are highly concentrated and solvation phenomena are not relevant, and the combination of these two factors often leads to accelerated reactions. This chapter provides an overview of the application of mechanochemical conditions to the synthesis of heterocycles, the compounds with the highest relevance for the pharmaceutical and agrochemical industries.

CHAPTER 8:Mechanochemical Synthesis of Biologically Relevant Heterocycles

The CAN-catalyzed three-component reaction between acrolein derivatives, β-dicarbonyl compounds and primary amines offers a general access to 1,4-dihydropyridines which can be diastereoselectively hydrogenated to provide piperidines with hitherto inaccessible stereochemical arrangement.

Fully Diastereoselective Synthesis of Polysubstituted, Functionalized Piperidines and Decahydroquinolines Based on Multicomponent Reactions Catalyzed by Cerium(IV) Ammonium Nitrate.

By the microwave irradiation of chlorinated N-heterocycles in presence of nucleophiles aromatic C—C or C—N bonds are generated regioselectively.

Lewis Acid‐Catalyzed Generation of C—C and C—N Bonds on π‐Deficient Heterocyclic Substrates.

Chapter 7 describes the chemical basis of the DNA intercalation process and several multimodal anticancer agents that exert their biological activity via intercalation with DNA and inhibition of topoisomerase II, other DNA-associated enzymes, or transcription factors that control genes involved in processes important for tumor progression and metastasis. It briefly discusses the role of topoisomerase I (Top1) and topoisomerase II (Top2), their mechanisms, and their inhibitors, discussing in detail structure modifications attempting to overcome the spontaneous and rapid inactivation of most camptothecin derivatives, the role of Top1 targeted agents as interfacial inhibitors, and the basis of Top1 inhibitors’ inherent resistance. The chapter shows the relevance of the Top2 poisons because they represent the largest group of approved agents among these targets, especially the anthracycline antibiotics previously discussed in Chapter 4 as precursors of radical species. It also discusses other Top2 poisons, particularly those related to the natural lignan podophyllotoxin, as well as the most relevant Top2 catalytic inhibitors. Among DNA-associated enzymes, telomerase inhibitors such as G-quadruplex stabilizers, inhibitors of telomerase reverse transcriptase (hTERT), and the RNA domain template are described (telomerase-based immunotherapy is discussed in Chapter 12). Finally, inhibitors of DNA repair processes, such as the nucleotide excision repair, are only enunciated because these agents are discussed in detail in Chapter 14.

Other Anticancer Drugs Targeting DNA and DNA-Associated Enzymes

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J. Carlos Menéndez

Papers

CHAPTER 8:Mechanochemical Synthesis of Biologically Relevant Heterocycles

Fully Diastereoselective Synthesis of Polysubstituted, Functionalized Piperidines and Decahydroquinolines Based on Multicomponent Reactions Catalyzed by Cerium(IV) Ammonium Nitrate.

Lewis Acid‐Catalyzed Generation of C—C and C—N Bonds on π‐Deficient Heterocyclic Substrates.

Other Anticancer Drugs Targeting DNA and DNA-Associated Enzymes

Fluorescence Sensors Based on Hydroxycarbazole for the Determination of Neurodegeneration-Related Halide Anions