There are none to be found. I've checked Gap, Old Navy, Target, the mall, Bluefly, Overstock.com, LandsEnd, Eddie Bauer, all the usual suspects. Sleeveless button ups are soooo not in this season. Curses. I tried to ignore all the gorgeous feminine blouses that ARE in and would be SO FUN to wear to work. (I love the swingy jacket with a long camisole underneath. Sigh.)
The closest I found was at Target, but beware: Their Merona white and black shirts do not button all the way up, which you cannot tell on the webpage. The Mizrahi white shirt does button all the way up, but is VERY shiny and a bit off white, which always looks weird with a collar, I think.
I did find this shirt at Target. Not black, but still cute and easily adaptable:
I then went into NY and Company, which I never do. I associate NY and Company with clothes my more fashionable friends wore in college, so never really considered them for "grown up" clothes, but now that I can no longer afford Banana Republic and Ann Taylor consistently, I was really, really impressed at the offerings of NY and Company. (And they have a AAA discount! AND their shirts were buy one get one 50% off!)
These shirts won't work with the jackets I bought, but they will look great on their own this summer. They had four different options in black, alone, though only one in my size. Anyway, I bought these:
If you can wear yellow, they also had the most beautiful yellow shirt with subtle white stripes that was really lovely. The website also has white, lavender and rose colored shirts.
If you find sleeveless black button up shirts, let me know! I'm still eager to wear the cute short sleeve jacket I found at Target this spring!