Unless you know of some secret section in the tax code, it's not a "2 for 1 deal" - if Bill Gates donates a billion dollars to a charity, it makes sense that it wouldn't be taxable; it's no longer his money. Typically the tax code reduces your income by money for which you don't actually have constructive use.

There are certainly other things like 'in-kind' donations which may reduce tax obligations without necessarily providing a commensurate value, but putting money into bona fide charitable works are not among them.