A chemoselective tandem reaction of a multi-reactive, two electrophile + two nucleophile, system is reported. An allylation/cross-coupling process of a haloaryl aldehyde, an aryl BPin, and an allyl BPin can be controlled using a temperature gradient to overcome natural reactivity profiles and allow two sequential chemoselective C-C bond formations without intervention. This process offers efficient access to an array of functionalised products including pharmaceutical and natural product scaffolds.