Unusual Intramolecular Bridging Reaction in Thiacalixarene Series
journal contributionposted on 2009-09-17, 00:00 authored by Ondrej Kundrat, Hana Dvorakova, Ivana Cisarova, Michaela Pojarova, Pavel Lhotak
Thiacalixarene immobilized in the cone conformation undergoes a direct formylation reaction giving unusual products in high yields. The Duff reaction (urotropine/TFA) leads to unprecedented intramolecularly bridged compounds possessing two formyl groups on the opposite para- or para-/meta-positions. The comparison with the corresponding classical calixarene analogues indicates an amazingly different reactivity of the thiacalixarene system.