Chiral esters and amides (I) of pyrrolidine-2-carboxylic acid are new. - Chiral esters and amides of pyrrolidine-2-carboxylic acid, having formula (I), are new. - A = groups F1 or F2; - R' and R'' = 1-20C hydrocarbyl, i.e. acyclic, linear or branched, saturated or unsaturated aliphatic, carbo- or hetero-cyclic, mono- or poly-cyclic, saturated, unsaturated or aromatic, or a chain of such groups, or R' and R'' are linked to form a 4-20 atom carbo- or hetero-cyclic group, saturated, unsaturated or aromatic, mono- or poly-cyclic; - Ar1 and Ar2 = two aromatic, carbo- or hetero-cyclic, rings optionally substituted, fused and/or containing one or more heteroatoms; - x and y = bonds between A and heteroatoms; - Rf = 1-20C hydrocarbyl, optionally containing at least one halo, preferably fluoro; - Rz = one or more substituents on pyrrolidinyl; - G = a chiral group; - W = O or RyN; - Ry = 1-20C hydrocarbyl as for R', or a chain of such groups; - n = number of ring substituents; - m = 0-3, preferably 0 or 1; - the wavy line = chiral bond; - the broken line = chiral or non-chiral bond. - An INDEPENDENT CLAIM is also included for a method for preparing (I) by reacting an N-protected pyrrolidine-2-carboxylic acid (or alkyl ester) with the appropriate alcohol or amine.