We have a boxwood hedge at my mom's house that is almost always shaded.
There is a peach tree about 5 feet to the west, and 5-foot high wood property fences 3 feet to the south and less than 1 foot to the east.
The boxwood receives virtually no direct sunlight. All possible sun angles are blocked by the fence, trees and the house itself.
Our part of town rarely drops below 35 degrees in winter so I cant say how much colder the boxwood can stand. But it did survive last January's nasty frost.
We do get hot summers that break into the 115 degree range and the boxwood did not seem to mind it at all.

I'm not sure exactly what type of boxwood we have, since it has been there ever since we bought the house.

It does get plenty (or maybe even too much) water from the lawn sprinklers, which probably helps during the hot summer months.

If I were you I would look in the Western Garden Book for something that can be under oak trees and tolerant of the oak fungus. There is a section for that.
Common Boxwoods are listed as tolerant but are expensive so you wouldn't want it to die right away. I get about the same temps as you not quiet that extreme sometimes and Boxwoods aren't tolerated here well in certain areas.

Thank you both for your comments. I should say that I have some boxwood (that I grew from cuttings) surrounding one of my garden beds in full sun, and they are just fine. So I don't think it's a problem that boxwood will grow here, but rather will they grow in the shade.

Thanx too goblurfim for the suggestion about checking the western garden book for something that can be under oak trees . I'd never thought of that.

I have boxwood growing in about 3 hours of sun with no summer water. They are about 15 years old and have not been watered since the first year. The soil is clay but is pretty well drained. Al

Will box woods grow in a spot where the sunline misses them by 2 feet.its not a dark shaded spot, but the direct sun does not hit them?