Uretaaniryhmät

Uretaaniryhmät, also known as urethane groups or carbamate groups, are a functional group in organic chemistry with the general formula R−N(R′)−C(=O)−O−R″. This structure features a nitrogen atom bonded to a carbonyl group, which is in turn bonded to an oxygen atom. The hydrogen atom on the nitrogen is replaced by an organic radical in secondary urethanes.

These groups are characteristic of urethanes, a class of polymers formed by the reaction between a diisocyanate and a diol. The urethane linkage is a key component in polyurethane chemistry, contributing to the unique properties of these versatile materials, such as flexibility, abrasion resistance, and elasticity. Urethanes find widespread applications in foams, coatings, adhesives, sealants, and fibers.

The urethane group can also be found in naturally occurring compounds and pharmaceuticals. For instance, certain carbamate-based insecticides and herbicides function by inhibiting enzymes essential for insect and plant survival. The stability and reactivity of the urethane linkage are influenced by the nature of the R, R′, and R″ substituents. Its presence signifies a specific type of amide and ester linkage combined.