Not really. The design of Bitcoin assumes that an attacker doesn't control more than 50% of the total mining power. If that's true, the level of protection provided by N confirmations decreases exponentially as N increases and is essentially independent of the confirmation time. This is all in Satoshi's original whitepaper.

If an attacker does control 50-plus percent of the total mining power, you're basically screwed. Increasing the total confirmation time doesn't increase the cost of a 51% attack by enough to be worth attempting.