It's not that simple. Of course, the direct effect of corporate taxes is mostly on the wealthy who own most of the stock but that's not necessarily the group who gets most of the wealth--more on that below. Even in terms of direct payments, wealth isn't the only important factor. As significant is a company's willingness to be creative. I have never seen a corporate tax scheme that's ungamable that doesn't involve giving the IRS more discretion post-hoc in applying the law nor is one feasible in practice given the resources a company tends to devote to minimizing a multi-billion dollar tax bill. So we have the perverse situation where, to a significant degree, tax creativity is a productive economic activity and belief in adhering more closely to the spirit of the law of punished with higher taxes.

As for the economic payers. Consider what happens if we eliminate corporate taxes: The company has more money. It can use that money in three general ways: Lower prices, raise pay or return it to shareholders. In a company with little competition, the optimal calculation is fairly simple. Does the additional return enable new entrants at current prices? Do we have employees who could leave and create competition and to what extent does the additional cash-flow make it more likely? In a competitive environment, the right answer is based on the sensitivity of profit to talent, the sensitivity of talent to pay increases, and the sensitivity of consumers to price decreases.

Given this different factors, what's the empirical answer? It varies based on circumstance and no one can say definitively. Here's an example of one attempt to answer based on variation in European tax rates that suggests that 49% of the taxes are paid by workers: http://www.econstor.eu/bitstream/10419/51691/1/66322666X.pdf. You can find many more papers with different points of view through your favorite search engine.