At the early beginnings, organic chemistry was taken by the scientific community as the chemistry of living matter. After the discovery of the synthesis of urea by Wohler in 1828, organic chemistry was defined as the chemistry of carbon-containing compounds.
Almost the entire amount of the carbon available on the earth surface exists in the form of carbonic acid (free or as calcium salts) and in fossil fuels obviously originated from living matter. It is well known that carbon dioxide is the necessary ingredient in the life cycle of animal and plants. Therefore, organic chemistry must be considered as strongly related to the chemistry of carbon dioxide and its derivatives.
Carbonic acid dichloride called « phosgene », discovered by John Davy in 1812, appears still nowadays the only efficient simple activated form of carbon dioxide, and despite intensive research done to replace it with less noxious starting material, phosgene remains a substitute for carbon dioxide.
