he jointly filed I-751 will be denied without the cooperation of your spouse. You can actually file the I-751 by yourself (with a waiver of the joint filing requirement) before the divorce is final but you will ultimately receive a request from USCIS for proof of a divorce, so you may want to have the divorce rolling before you file the I-751.
You cannot get an approval for the jointly filed I-751 if your wife does not cooperate with you. You don't have to wait to be denied. I have handled cases such as this. You can actually make an amendement to the application, but you may not have enough time to get he divorce finalized before the waiver is decided on by USCIS. Contact an attorney to help make this less stressful for you.
Cooperation is not enough. Either you file jointly while you live together or you need a waiver.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.
You may need to file an amendment if your spouse is not cooperating.
Angelique Montes, Esq., Immigration Attorney in Houston, Texas. This is not legal advice and a client-attorney relationship is not created. The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.