This is your own fault. You've made your "boss" believe that you can complete designs without content for so long that he now expects it. You should try re-framing the conversation. Something like:

— SCENE: BOSS TYPING FURIOUSLY, YOU KNOCK ON HIS DOOR AND HE INVITES YOU IN.

BOSS: "We need this design for our new sprocket page as soon as possible - We're going to market in two weeks and need a landing page for our Google AdWords campaign"

YOU: "Awesome! The new sprocket is going to be huge for our company. What would you really like to focus on for this page? I want to make sure to prominently feature the most important things."

BOSS: _excitedly lists a dozen things_

YOU: Wow - this thing is really great. It's going to be a huge benefit to our customers. How can we show them the three things they're going to react to instantly?

BOSS: "Well my favorite is the gizmosis feature. It makes it so you don't have to flim-flam any more!"

YOU: "Woah. That's really cool! I'll make sure that is billed highly. Anything else you can thing of that sticks out in your mind?"

BOSS: "That's the only thing that sticks out. I do have this detailed list of features here"

YOU: "Please do send that to me - I'll try to make some sense of it. If you think of anything else really important, just email it over to me. I'm going to start putting all of these features into the design tomorrow morning - so make sure you let me know by the end of the day! I can't wait to get this page up for our clients to see - it's going to be a huge win."

BOSS: "Excellent. I'll send over any additional thoughts I have with that document right now. Thanks."

— END SCENE

Framing the conversation is important. Seeing yourself as the boss's advocate is important. You're working toward the same goal. The content is more important than your design. Accept that.