Only US Citizen have the ability to apply for an immigrant visa with out the wait for a Visa number.
The only thing you can do in your case, is to apply for the visa, and return home before your current visa expires, and wait for the visa number to come up from the state department.
QUOTE
LIMITED FAMILY-BASED
Family First Preference (F1): Unmarried sons and daughters of U.S. citizens, and their children, if any. (23,400)
Family Second Preference (F2): Spouses, minor children, and unmarried sons and daughters (over age 20) of lawful permanent residents. (114,200) At least seventy-seven percent of all visas available for this category will go to the spouses and children; the remainder will be allocated to unmarried sons and daughters.
http://travel.state.gov/visa/immigrants/ty...types_1306.htmlIf or when he naturalizes, he can notify the NVC and USCIS of the change of status, and they will move the petition to CR-1/IR-1 for spouse of a US-Citizen and move it on to the consulate in the foreign country.