The Battle of Midway is rightly seen as the turning point in the Pacific theatre of WWII. I've wondered, had the Battle of Midway instead been won (captured Midway) by the Japanese what plans did the allies have if any? According to Wikipedia the Japanese hoped a victory could has brought the US to the negotiations table. Is this realistic?
It was not a realistic position in the least. Even if all three US carriers at Midway had been sunk, the first of the Essex-class carriers was launched just over a month later, with the Independence-class CVLs coming just afterwards. By August of 1943, all three of those sunk carriers would have been replaced by newer, bigger, more powerful carriers (though it would have taken a few more months for them to be ready to fight). In short, the Americans would have just waited for their new carriers and planes to hit the water, then gone out and done bad things to the Imperial Japanese Navy.
If the Japanese had captured Midway, it would have been difficult for them to keep supplied, particularly as the US submarine force cranked up their freighter hunting. There's some question as to whether the Japanese could have successfully invaded Midway, but that's a different question.
A US Navy loss at Midway would have extended the Pacific War by another year, maybe two, but that's it.
references: I'm an amateur historian of the Pacific war, with an emphasis on the Battle of Midway. A few of my collection of books on the subject can be found here.