A process of preparing olefins of the formula (I) is described herein: ##STR00001##
with R.sup.1 being a substituted or unsubstituted (C.sub.1-C.sub.30)hydrocarbyl, and R.sup.2 being a substituted or unsubstituted (C.sub.1-C.sub.20)hydrocarbyl. The process includes reacting a compound of formula (II) ##STR00002##
wherein Ar is chosen from ##STR00003##
in the presence of a palladium-based catalyst and an organic solvent. A process of preparing olefins of the formula (III) is also described: ##STR00004##
with R.sup.3 being a substituted or unsubstituted (C.sub.1-C.sub.30)hydrocarbyl, R.sup.4 being a substituted or unsubstituted (C.sub.1-C.sub.20)hydrocarbyl, and R.sup.5 being a substituted or unsubstituted (C.sub.1-C.sub.30) hydrocarbyl. The process includes reacting a compound of formula (IV) ##STR00005##
wherein Ar is chosen from ##STR00006##
with a compound of formula (V) ##STR00007##
wherein Ar is chosen from ##STR00008##
in the presence of a palladium-based catalyst and an organic solvent.