1. you are running this all as a sole proprietorship, with no separation of business and personal money. In that case? sort of. Your accounting is going to be complex as heck. if you have $100K of assets to donate, donating those assets can offset $100K of income. you are giving up an amount equal to what you are earning to avoid taxes, it's a lot like not paying yourself, and selling and living off of the assets you donated, except you avoid some of the extra taxes you would have paid on doing that. Also note, in this case, the stuff you have to pay FICA on is... complicated, and your charitable donations usually don't get you out of FICA (which if you are rich you don't care about, but we're talking about $125K/yr, and as you are paying employee and employer, thats 15% - without selling the company or without paying both corp income tax and personal capital gains for a dividend, it's hard to take money out of a company without paying FICA.)
Note, this is pretty unusual for people who know what they are doing. This is how I started out, and it was a real mess to untangle. Most people compartmentalize their businesses into several entities, and not just for liability protection (though that is nice, too) - Accounting works much better when your money isn't just one big pool.
2. this is the common thing. your businesses are their own tax entities. You have a LLC (often several) for your real estate, an S corp for your consulting/speaking income, C corps for a lot of your other businesses:
In that case? having a business entity I control that is taxed as a c corp donate a bunch of money is going to change taxation for that entity. Not for the personal money I pay myself.