You can read about some theories of Pre-columbian transatlantic contact in our FAQ, though I don't believe the Phoenicians are specifically addressed. Now I've heard theories that Africans crossed the Atlantic and founded the Olmec civilization, bringing with them some Phonecian navigators; you can find my rebuttal to that theory here. As for the Phoenicians themselves, though, I've only heard theories that they rounded Africa- mind sharing where you saw the Brazil theory? There's really no evidence for such a thing and I'd like to see how people are supporting it.