Imidazolium-based polymer supported gadolinium triflate as a heterogeneous recyclable Lewis acid catalyst for Michael additions

Copolymerization Involving Sulfur-Containing Monomers

Incorporating sulfur (S) atoms into polymer main chains endows these materials with many attractive features, including a high refractive index, mechanical properties, electrochemical properties, and adhesive ability to heavy metal ions. The copolymerization involving S-containing monomers constitutes a facile method for effectively constructing S-containing polymers with diverse structures, readily tunable sequences, and topological structures. In this review, we describe the recent advances in the synthesis of S-containing polymers via copolymerization or multicomponent polymerization techniques concerning a variety of S-containing monomers, such as dithiols, carbon disulfide, carbonyl sulfide, cyclic thioanhydrides, episulfides and elemental sulfur (S8). Particularly, significant focus is paid to precise control of the main-chain sequence, stereochemistry, and topological structure for achieving high-value applications.

Conformational control of nonplanar free base porphyrins: towards bifunctional catalysts of tunable basicity

No metal needed: nonplanar free base porphyrins act as bifunctional organocatalysts revealing a new mode of action for porphyrins.

Ionic tagged DABCO grafted on magnetic nanoparticles: a water-compatible catalyst for the aqueous aza-Michael addition of amines to α,β-unsaturated amides

A water compatible DABCO grafted on magnetic nanoparticles with an ionic tag has been developed and used to catalyze the aza-Michael addition.

Amidation of aldehydes and alcohols through α-iminonitriles and a sequential oxidative three-component Strecker reaction/thio-Michael addition/alumina-promoted hydrolysis process to access β-mercaptoamides from aldehydes, amines, and thiols

Mild and general alumina-promoted hydrolysis conditions for converting α-iminonitriles into carboxamides have been developed. In combination with the oxidative three-component Strecker reaction, the one-pot direct amidation of aldehydes and alcohols is reported. Subsequently, an Yb(OTf)(3)-catalyzed Michael addition of thiols to α,β-unsaturated α-iminonitriles is reported for the synthesis of β-mercapto-α-iminonitriles. The successful integration of an oxidative Strecker reaction, thio-Michael addition, and neutral-alumina-promoted hydrolysis of β-mercapto-α-iminonitriles into a three-component one-pot process allowed us to develop the direct conversion of amines, aldehydes, and thiols into β-mercaptoamides. All of these procedures were applicable to aromatic and aliphatic amines and aldehydes.