In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO.sub.2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having one or more sites capable of initiating copolymerization of epoxides and CO.sub.2, wherein the chain transfer agent contains one or more masked hydroxyl groups. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of OH end groups, a high percentage of carbonate linkages, and substantially all polycarbonate chains having hydroxyl end groups have no embedded chain transfer agent.

The present disclosure relates to an asymmetric process for preparing nicotine without protection, in particular to a process for preparing optically pure nicotine by taking nicotinate as a starting material and carrying out four-step reaction. The process comprises the following steps: nicotinate and -butyrolactone are subjected to condensation reaction, asymmetric catalytic reduction reaction, activation, and reaction with methylamine to give optically pure nicotine. The asymmetric catalytic reduction for preparing the chiral alcohol intermediate compound with high optical activity is a key step of the method. The method of the present disclosure has the characteristics of high atom economy, very high reaction activity, capability of keeping excellent stereocontrol, capability of obtaining a chiral product with very high enantioselectivity, short reaction steps, low cost of raw materials, green and pollution-free, capability of greatly reducing the quantity of three wastes, and easiness in realizing industrial amplification production.

A catalytic carbon capture material is provided. The catalytic carbon capture material includes a microporous polymer including a Trger's base moiety, and a transition metal is coordinated within the microporous polymer. The catalytic carbon capture material selectively captures carbon dioxide (CO.sub.2) and also is a catalyst that simultaneously converts the captured carbon dioxide into one or more carbon dioxide-based products. A method of making the catalytic carbon capture material and a method of selective carbon dioxide capture and conversion are also provided.

In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO.sub.2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having one or more sites capable of initiating copolymerization of epoxides and CO.sub.2, wherein the chain transfer agent contains one or more masked hydroxyl groups. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of OH end groups, a high percentage of carbonate linkages, and substantially all polycarbonate chains having hydroxyl end groups have no embedded chain transfer agent.

Methods, systems, and compositions for oxidation are provided. The method comprises combining a macrocyclic ligand and metal complex catalyst, an electrolyte, the substrate, and water to form an aqueous composition. The method comprises applying an electrical voltage to the aqueous composition and oxidizing the substrate in the presence of the catalyst.