That is the ideal but that isn't reality. The big corporations have large departments devoted to tax avoidance. Where does that saved money go? Usually distributed as dividends to shareholders, executive bonuses, or enormous bank accounts where the money does nothing (e.g. Apple).

The best way to improve the economy is put more money into the hands of normal people so that they will buy more stuff which in turn helps those businesses. Lowering or eliminating income taxes for non-rich people would help far more than a tax break for the rich which includes companies.