Covalently Linked at the Lower Rim Double‐Calix[4]arene as a Precursor for Multicavity Supramolecular Receptor

New covalently linked at the lower rim double‐calix[4]arens, which have great potential for the synthesis of multicavity receptors, were prepared via Sonogashira cross‐coupling reaction. The structures of 6 and 7 were confirmed by NMR, MS, and elemental analysis.     

Poly(N‐bromobenzene‐1,3‐disulfonamide) and N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide as a mild and efficient catalyst for chemoselective thioacetalization of carbonyl functions and transthioacetalization reactions

Poly(N‐bromobenzene‐1,3‐disulfonamide) and N,N,N′,N′‐tetrabromobenzene‐1,3‐disulfonamide are effective catalysts for chemoselective dithioacetalization of aldehydes in the presence of ketones under neutral conditions. J. Heterocyclic Chem., (2011).