Organic radical reactions confined to containers in supramolecular systems

Abstract

Organic radical transformations confined to containers in supramolecular systems are highlighted.

Control of reactivity and selectivity in isomerization and rearrangement reactions inside confined spaces

“…Rearrangement reactions, where a substituent moves from one atom to another atom in the same molecule, are also an important step in the synthesis of natural products, bio-active molecules, and various valuable products. 5,6 Alongside substitution and addition reactions, rearrangements are of fundamental importance within organic synthesis. Moreover, they are useful for the construction of complex molecular frameworks and impossible or hard-to-get synthetic methods.…”

“…But the same process in the confined space of a supramolecular container can be controlled to give reaction and product selectivity. 5,6…”

“…Recently, many reviews have been reported based on investigating the use of containers in diverse concepts on the control of the conformation of binding guests, reactivities, and possibilities for the processes mediated by a supramolecular host. 2 c , d , g – j ,3 c , e ,5,6 d Exploring the confinement provided by the host to the guest and the non-covalent interactions specific to the mediated reactions is crucial and necessary for research progress. In this highlight, we mainly discuss the effect and importance of confined spaces (diverse in architecture and composition) and different driving forces in the product selectivity of reversible and rearrangement reactions.…”

“…The cis – trans isomerization of olefins is one of the key photoreactions involved in several biological events. 1–6 In order to understand the effect of confinement provided by biological systems, many confined spaces within supramolecules have been reported. As the guest is separated from the bulk by complexation in the host cavity, the excited state of the molecule is based on the “ confined space ”.…”

“…The Ramamurthy and Gibb groups reported various types of photoreactions mediated by OA 2 and its amplified “cage” effect. 5,30 For example, dibenzylketone (R = H), 16 underwent Norrish type (α-cleavage) reaction upon photoexcitation and produced the decabonylated product, 16b as the sole product in hexane medium. However, the reaction in the OA 2 cavity yields rearranged product ( 16a , 56%,) as the major product.…”