You can't really target individual neighborhoods like that. Targeting a neighborhood for development raises the costs of living there and prices the locals out, which is the entire cause gentrification.

In theory a better idea to raise income first (ie, better wages/jobs) and then develop, but that's also a vicious cycle as people will generally move out of trashy areas as soon as they afford to.

I think the only way to do it is to reduce income inequality accross the board, thus making the poverty divide less intense in the first place. We can't do that though, because taxing the ultra wealthy and building public infrastructure with it is "socialism." /s