 Despite this, palladium catalysts are able to promote a wide variety of cross-coupling reactions including biaryl formation and aryl alkyne formation, along with a variety of cross-coupling reactions in which the carboxylic acid is not bonded to an aromatic.Other Pd-catalyzed decarboxylation cross-coupling reactions include conjugated diene preparation (see dienes and trienes below) and dehydrogenative reactions (with a variety of substrate and catalyst combinations).Contrarily to Cu-only systems, decarboxylative palladation is the rate-limiting step in the palladium catalytic cycle.