Can I give a large gift from my pre-tax 401K to a charitable organization tax free? Should I transfer the funds to an IRA ? Should I gift some of the funds to my wife?

The direct charitable contribution can only be the Required Minimum distribution (RMD) which you do not have until age 59 1/2.

You would have to take the money out of the account, which would be taxable income and then make a gift.

Or leave the charity as a beneficiary of the retirement account, or wait until 70 1/2 and do the RMD that way each year.

And, once an individual reaches age 70½, if you want the contribution excludible from income it must come from an IRA, not from a 401(k).  To be able to make Qualified Charitable Distributions in the year the individual reaches age 70½ and beyond, prior to the year that individual reaches age 70½ that individual will want to roll the money from the 401(k) to an IRA.

I donated to a charity directly from my retirement accounts, how do I exclude the amount from my AGI?