I would advice you to check the reasons for your Google AdSense application getting rejected. Your blog may have certain serious violations of Google policies. When Google rejects your application, it clearly mentions the reasons for the rejection. It also provides you with the suggestions.
And in case, your blog has any issues that Google considers not suitable for an approved AdSense account, using your friend's account on your blog can have serious implications for his account.
Moreover, the earnings from your friend's AdSense account will be transferred to him and as such this might create rift between you over financial matters.
Instead of going that way, I would advice you to improve upon your blog. Write some high quality posts. Get some decent organic traffic. Be innovative and unique with your content. Having done that, you can re-apply for the AdSense account. If you meet all the requirements for a AdSense account, I can't see why your AdSense application gets rejected.
If you are still in doubt about getting approved, go for a blogspot blog and write a few good quality articles. Wait for some good traffic and apply for a hosted account through it. Once you get the hosted account, you can place a request to use the account on your blog.
Live....and Let Live!