Yews can handle some shade and should have no problem growing in that environment. I put up a privacy fence and then attached a wooden trellis across the whole length and planted clematis that gets morning shade and afternoon sun. Perennials shade the roots. My neighbor loves it.

I think you might be confused about the terms "full sun" & "full shade" and the concept of direct sunlight. "Full sun" is an area that receives direct sunlight for at least 6-8 hours per day. An area that receives direct sunlight starting in the afternoon, such as a Western exposure, should be planted with things that are for full sun.
In addition to a columnar yew, there are upright, narrow junipers that would work in your situation.

"An area that receives direct sunlight starting in the afternoon, such as a Western exposure, should be planted with things that are for full sun" Entling is absolutely right. Typical shade plants will fry in afternoon sun in Missouri.
Be careful not to get something that will get bigger than you want unless you plan to use hedge trimmers on them. Plant tags aren't very accurate a lot of times.

You also need to consider how your a/c unit vents and give it enough room to be serviced--if it vents up, you are fine--if a side vent, then nothing will grow near the vent due to the heat generated.