A one-pot synthesis of polymerizable and acyclic urea (meth)acrylates, preferably mono(meth)acrylates, can be performed via in-situ synthesis of urea alcohols or amines followed by direct reaction with a (meth)acrylate reactive diluent. The urea alcohol/amine is obtained from isocyanates and alcohols, amines, or hydroxyamines. Subsequently, the reaction with the (meth)acrylate reactive diluent takes place and the urea (meth)acrylate is directly obtained either in solution with the reactive diluent, or as a pure material after removal of the reactive diluent.

Catalysts and catalytic processes for the synthesis of acrylic acid and other α,β-unsaturated carboxylic acids and their salts, which are carried out in a diluent or in the absence of a diluent. In an aspect, ethylene and CO.sub.2 can be contacted with a Group 8-11 transition metal precursor compound or a Group 8-11 transition metal metalalactone compound in the presence of a metal-treated chemically-modified solid oxide (MT-CMSO) or a metal-treated solid oxide (MT-SO), to form a metal acrylate. As the catalytic activity wanes in either the presence or absence of a diluent, pressure cycling—that is, pressurizing the reaction system with CO.sub.2 and an olefin such as ethylene for a time period, releasing the pressure, then re-pressurizing with CO.sub.2 and ethylene—can rejuvenate the catalyst and restore its declining catalytic activity.

Catalysts and catalytic processes for the synthesis of acrylic acid and other ,-unsaturated carboxylic acids and their salts, which are carried out in a diluent or in the absence of a diluent. In an aspect, ethylene and CO.sub.2 can be contacted with a Group 8-11 transition metal precursor compound or a Group 8-11 transition metal metalalactone compound in the presence of a metal-treated chemically-modified solid oxide (MT-CMSO) or a metal-treated solid oxide (MT-SO), to form a metal acrylate. As the catalytic activity wanes in either the presence or absence of a diluent, pressure cyclingthat is, pressurizing the reaction system with CO.sub.2 and an olefin such as ethylene for a time period, releasing the pressure, then re-pressurizing with CO.sub.2 and ethylenecan rejuvenate the catalyst and restore its declining catalytic activity.

A one-pot synthesis of polymerizable and acyclic urea (meth)acrylates, preferably mono(meth)acrylates, can be performed via in-situ synthesis of urea alcohols or amines followed by direct reaction with a (meth)acrylate reactive diluent. The urea alcohol/amine is obtained from isocyanates and alcohols, amines, or hydroxyamines. Subsequently, the reaction with the (meth)acrylate reactive diluent takes place and the urea (meth)acrylate is directly obtained either in solution with the reactive diluent, or as a pure material after removal of the reactive diluent.