N-Acyl-N-(4-chlorophenyl)-4-nitrobenzenesulfonamides: highly selective and efficient reagents for acylation of amines in water

A variety of N-acyl-N-(4-chlorophenyl)-4-nitrobenzenesulfonamides (1a–e) were synthesized in one pot from 4-chloroaniline under solvent-free conditions and have been developed as chemoselective N-acylation reagents. Selective protection of primary amines in the presence of secondary amines, acylation of aliphatic amines in the presence of aryl amines, and monofunctionalization of primary-secondary diamines as well as selective N-acylation of amino alcohols using these reagents are described. All of the acylation reactions were carried out in water as a green solvent. High stability and easy preparation of these acylating reagents are other advantages of this method.

Efficient microwave synthesis of novel aromatic esters catalyzed by zirconia and its modified forms: a kinetic study

A series of solid acids such as ZrO₂, 5%Mo(vi)/ZrO₂, 10%Mo(vi)/ZrO₂, 20%Mo(vi)/ZrO₂ and SO₄²⁻/ZrO₂ were prepared, characterised and used as catalysts in the synthesis of novel esters under microwave irradiation condition.

PMoA/MCM-41 catalyzed aza-Michael reaction: special effects of mesoporous nanoreactor on chemical equilibrium and reaction rate through surface energy transformation

Nanoreactors as catalysts can affect not only speed but also the chemical equilibrium of the reaction under investigation.

Direct dehydrative esterification of alcohols and carboxylic acids with a macroporous polymeric acid catalyst

A macroporous polymeric acid catalyst was prepared for the direct esterification of carboxylic acids and alcohols that proceeded at 50-80 °C without removal of water to give the corresponding esters with high yield. Flow esterification for the synthesis of biodiesel fuel was also achieved by using a column-packed macroporous acid catalyst under mild conditions without removal of water.