Regioselectivity Switch Towards the Development of Innovative Diels‐Alder Cycloaddition and Productive Applications in Organic Synthesis

Abstract

The Diels‐Alder (DA) reaction is one of the fascinating synthetic strategies known for its pericyclic action and concerted mechanism that leads to various targets. Numerous synthetic pursuits have been rewarded with conceptually distinct and efficient ways. To date, extensive and spectacular accomplishments have been made in the field of Diels‐Alder chemistry to overcome the complexities of organic synthesis that inspired organic chemists to focus on expanding and establishing the postulates. In principle, DA reactions are governed by their straightforward reactivity pattern with a high degree of certainty, primarily attributed to the HOMO‐LUMO separation of reacting partners. Furthermore, general forecasts rely on account of background studies, conveniently hypothesizing the stereochemical outcomes and reaction dynamic pathways. DA has recently emerged as a technique for establishing a variety of products from the same reacting species under varying reaction conditions rather than a general reactivity profile. Such exceptional results are of significant interest in organic synthesis to pursue the challenges of unanticipated product establishment. Herein, we summarize the impressive finding of the remarkable switch in the regioselectivity and diastereoselectivity of DA reactions under a diverse set of reaction protocols in light of Diels‐Alder's unending importance in chemical science. This review aims to establish a beneficial account of Diels‐Alder towards the astonishing switches extended to study varying synthetic versions in organic synthesis protocols attributed to natural and biologically active scaffolds. This review also provides insight into distinct reaction dynamics in DA reactions that are subjected to access molecular frameworks ranging from simple to complicated ones to foster high levels of innovation in chemical sciences.

[RhCp*Cl2]2-Catalyzed Indole Functionalization: Synthesis of Bioinspired Indole-Fused Polycycles

“…The selected topic is encouraging because functionalization has received less attention than the synthesis of indole, especially in terms of catalytic conversions, and a huge number of compilations have been devoted to it. This work aims to highlight recent advancements, focusing on creating unique, stable carbon–carbon and carbon–hetero bonds (based on our expertise in assembling C–C bonds) to create scaffolds inspired by polycyclic indoles. − The most effective ways to functionalize indoles are through catalyst-controlled chemo-divergent synthesis, oxidative cascade annulations, oxidative [4 + 2] annulations, reductive aromatization, and dearomatization via cross-coupling reaction over preactivated indole derivatives. These methods are well-illustrated using Rh­(III) catalysis pathways.…”

Recent advances in cascade reactions and their mechanistic insights: a concise strategy to synthesize complex natural products and organic scaffolds

“…It will also be influential in demonstrating structural diversity and costeffective organic synthesis protocols, which are promising alternatives to time-consuming long-route synthetic approaches as disclosed before. [111][112][113] Overall, we hope it will serve as a resource and source of inspiration for researchers interested in cascade-encouraged synthetic endeavours.…”