Highly Selective Radical Monoreduction of Dihalides Confined to a Dynamic Supramolecular Host
Reduction of alkyl dihalide guests (2–5 and 7) with trialkylsilanes (R3SiH) was performed in water-soluble host 1 to investigate the effects of confinement on fast radical reactions (k≥103 m?1 s?1). High selectivity (>95 %) for mono-reduced products was observed for primary and secondary dihalide guests under mild conditions. The results highlight the importance of host–guest complexation rates to modulate the product selectivity in radical reactions.
Petroselli, Manuel,Rebek, Julius,Yu, Yang
supporting information
p. 3284 - 3287
(2021/02/05)
Radical Reactions in Cavitands Unveil the Effects of Affinity on Dynamic Supramolecular Systems
Radical reduction of alkyl halides and aerobic oxidation of alkyl aromatics are reported using water-soluble container compounds (1 and 2). The reductions involve α,ω-dihalides (4-8 and 10) with radical initiators in cavitand hosts with varied binding affinities. Product distributions lead to general guidelines for the use of dynamic supramolecular systems with fast reactions. The binding of guest substrates in the hosts must show high affinities (Ka> 103M-1) to ensure that the reactions take place under confinement in the containers.
