This only works if you are already itemizing deductions.
If the company gives you the money, then you can only deduct the donation if you itemize deductions.
However, if the company donates the money, then it's not part your taxable income - in other words, it's "pre-deducted".
Another example would be Flexible (Health) Spending Accounts - FSAs:
Normally, you can only deduct health care expenses when you itemize deductions AND only the amount over a certain percentage of your adjusted gross income (AGI).
But, with a FSA, the money is put into an escrow account that you (mostly*) control. AND is deducted from your pay BEFORE taxes, thus reducing your taxable income. Therefore, you are effectively deducting the whole amount, not just the amount over the AGI percentage AND even if you don't itemize deductions.
* Once money is put in the FSA, you can only use it to pay qualified medical expenses AND you loose any remaining amount still in the FSA at the end of the year (though there are certain "grace rules" that might apply).