A chiral catalyst comprising a 3, 4-disubstituted pyridine, or a salt, N functionalised derivative, dimer or oligomer thereof, wherein the 3-substituent is substantially hindered from rotation about the bond (sp.sup.2-sp.sup.2 biaryl axis) linking it to pyridine and the 4-substituent is an aliphatic or aromatic amine linked by a single bond to the pyridine, the pyridine nitrogen being functionalised or unfunctionalised, preferably comprising a compound of formula I ##STR00001## wherein Z is a group substantially hindered from rotation about its bond; and each of R.sup.1 and R.sup.2 are independently selected from C.sub.1-30 alkyl, C.sub.3-30 cyclo alkyl and/or C.sub.3-30 aryl, or NR.sup.1 R.sup.2 form a cyclic amine; wherein R.sup.1 and/or R.sup.2 may be optionally substituted and/or include one or more heteroatoms; a composition or support comprising the catalyst; process for the preparation and resolution thereof; process for stereoselective reaction of an optically inactive substrate using the catalyst; and the optically active reaction product thereof.