Similarly, boronic esters possess one alkyl substituent and two ester groups. The most stable conformation will be the one which has the substituent or substituents equatorial. Carbonic acid is a carboxylic acid with a hydroxyl group as the substituent. Cyclohexyl is the alkyl substituent of cyclohexane and is abbreviated Cy. It is a derivative of pyridine with a carboxylic acid substituent at the 4-position. Arylation is the process in which an aryl group is attached to a substituent. It is a derivative of pyridine with a carboxylic acid substituent at the 2-position. Addition of phenyl cyclopropylamine substituent in the 5 position gave high affinities. This transition state likely occurs because of favorable pi-stacking with the phenyl substituent. The fluorine atom is para with respect to the substituent Z in the benzene ring. Benzaldehyde (CHCHO) is an organic compound consisting of a benzene ring with a formyl substituent. In unsymmetrical ethylated compounds, the methylene protons in the ethyl substituent are diastereotopic. IAA is a derivative of indole, containing a carboxymethyl substituent. It consists of a 15-membered ring ketone with one methyl substituent in the 3-position. The phosphate 1 contains a chiral group with a hydrogen and a deuterium substituent.