Recent Progress towards Organocatalyzed Asymmetric (Hetero)Arene Formation

Abstract

Owing to the importance of arene moieties in organic chemistry, methods for arene construction attract great attention. Besides the traditional substitution strategy from pre-existing arenes, the straightforward formation of arene cores can also provide significant shortcuts towards a wide array of target molecules with different substitution patterns. Among direct arene formation reactions, applying environmentally benign organocatalysis to access arene moieties continues to attract increasing attention. This short review provides a brief summary of recent progress on organocatalyzed de novo (hetero)arene formation and applications in enantioselective synthesis.1 Introduction2 Arene Formation with Non-Covalent Organocatalysts2.1 Arene Formation with Acid Organocatalysts2.2 Arene Formation with Base Organocatalysts2.3 Arene Formation with Hydrogen-Bonding Organocatalysts3 Arene Formation with Covalent Organocatalysts3.1 Arene Formation with Lewis Base Organocatalysts3.1.1 Arene Formation with Secondary Amine Organocatalysts3.1.2 Arene Formation with Tertiary Amine, Tertiary Phosphine and Sulfide Organocatalysts3.1.3 Arene Formation with N-Heterocyclic Carbene Organocatalysts3.2 Arene Formation with Lewis Acid Organocatalysts4 Conclusion

Enantioselective Synthesis of Atropisomers by Oxidative Aromatization with Central-to-Axial Conversion of Chirality

“…Beyond oxidation reactions, such as the one used in the seminal example by Meyers and which will be the focus of this review, other mechanistic pathways are available to achieve conversions of chirality and have been discussed in more general reviews [ 46 , 47 , 48 , 49 , 50 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 ]. We can notably cite eliminations [ 83 , 84 , 85 , 86 , 87 , 88 ], retro-cycloadditions [ 89 , 90 ], opening of strained rings [ 91 ], and tautomerizations and isomerizations [ 57 , 92 , 93 ].…”

Visible light-mediated radical-cascade addition/cyclization of arylacrylamides with aldehydes to form quaternary oxindoles at room temperature

“…Nitrogen-containing heterocycles are commonly found in organic compounds and are also among the most significant structural units of pharmaceutical molecules. 5 Specifically, oxindoles and their derivatives represent a large class of N-heterocycles that have aroused great interest from researchers due to their meaningful scaffolds in natural products and their prominent pharmaceutical and biological activities, 5 a ,6 such as anti-diabetic, anti-cancer, anti-bacterial, anti-tumor, anti-oxidant, anti-HIV and analgesic activities. Some representative examples are shown in Fig.…”