RESUMO
In this work, an irregular calixpyridinium-suramin sodium supramolecular assembly was constructed by the strong host-guest electrostatic interactions. More interestingly, a novel regular spherical supramolecular assembly was also fabricated by the hydrogen bonding interactions between suramin sodium and the UV accelerated addition product of deprotonated calixpyridinium in water. The same principle was also applied to construct a UV accelerated regular spherical self-assembly by the addition product of deprotonated calixpyridinium in water. Compared with the complicated and irreversible covalent connection of the light-responsive groups to the building block, which is one of the common means of obtaining light-responsive supramolecular systems, this finding not only provides a smart, facile, and universally applicable method to construct deprotonated calixpyridinium-based light-responsive host-guest systems but also provides a new idea for the development of other novel light-responsive building blocks.
RESUMO
An unprecedented cascade Heck-Aldol-Heck reaction was developed to form two C-C single bonds and one C=C double bond in one process by a combination of palladium(0) catalysis and aminocatalysis. Various aryl iodides could perform the cascade reaction with readily available propenol and formaldehyde to afford novel (E)-trisubstituted alkenes in 66-81% yields.