I think you are barking up the wrong tree.
Let's say you have to sell a house for $1m and the taxable gain is $500k. Your marginal tax rate today is 33%, your marginal rate next year and forever into the future is 0%. So if you sold today for $1M you would pay $165k in taxes ($500k @ 33%) and receive $835k after-tax.
Option 1: Invest $835k in the stock market and earn average 6%/year over 30 years. In 30 years that compounds to $4,796k.
Option 2: Receive zero cash today and $50k/year for 30 years from the insurance company. As you receive those payments you invest them in the market at 6%. In 30 years you end up with $3,953k.
So even though option 2 saves you $165,000 in taxes, you are worse off by $843,000 in 30 years by using the insurance annuity.
Now obviously the risk of investing in the market is greater than the credit risk of an insurer but you can decide whether that risk is worth $843k to you. And of course you can change these assumptions to make the annuity look better, for extremely large capital gains and tax rates it might make sense. And the annuity would look better if you can direct only the capital gains portion of the sale to the annuity and take some of the cash upfront (I have no idea, but I suspect the IRS makes you prorate it). But in general, I think these circumstances will be hard to find in reality.