Hi there. At this time, Logic Pro 11 does not auto-detect chords. If you are dragging in Apple Loops and those specific loops have built in "Region Chords" then YES, you can then begin to use those chords within your session. This is determined by the "Region Chord" icon next to the key found in the Loops Browser.
More info here:
Apple Loops and chords
Many Apple Loops also contain region chords, and many Apple Loops designed to be used together share compatible chords. When you add a loop containing chords to the Tracks area, you can choose to have the chords be copied to the Chord track so that they are followed by the Session Players in the project. See Add Apple Loops to your projects.
I should also mention that there are lots of great chord detecting tools in the market. Some of my favorites are Melodyne,
Chorddetector by DDMF, and Chord.ai (Application).
Hope this helps,
Eddie G.