Abstract: This disclosure relates generally to olefin metathesis, and more particularly relates to the synthesis of terminal alkenes from internal alkenes using a cross-metathesis reaction catalyzed by an olefin metathesis catalyst. According to one aspect, for example, a method is provided for synthesizing a terminal olefin, the method comprising contacting, in the presence of a ruthenium alkylidene metathesis catalyst, an olefinic substrate comprised of at least one internal olefin with a cross metathesis partner comprised of an alpha olefinic reactant, under reaction conditions effective to allow cross-metathesis to occur, wherein the reaction conditions include a reaction temperature of at least 35° C. The methods, compositions, reactions and reaction systems herein disclosed have utility in the fields of catalysis, organic synthesis, and industrial chemistry.