"Autumn Leaves" is really an alternation between the major key and its relative minor:
ii-V-I-IV-vii in G major
ii-V-i in E minor
The Em7 becomes the vi in G major again, leading back to Am7.
In the bridge, the sequence is reversed. It starts with the ii-V-i in E minor (F#m7b5-B7-Em) and goes on to a ii-V-I in G major.
Finally (C section) it works its way back to the minor key tonic (Em).
In the melody, the E melodic minor scale is used on the B7 (bar 6) - which is a clue for what you can do as a soloist.
Otherwise, the G major scale will cover just about everything - as long as you're aware of how it shifts to E minor all the time.
The D minor pent - is that what you really meant? - won't work in the bridge (IMO) - it has an F natural, which is definitely out of key - except on the B7 (oddly, see below).
I'd suggest using E minor pent (or even B minor pent might sound cool), but also thinking about the chord arpeggios. Go for the interesting chord tones that aren't in the scale: the D# on the B7, the C on the F#m7b5 (the B7 can have a b9, C, too).
A more advanced jazz choice would to superimpose other minor pents or arpeggios: Am on the F#m7b5, and Cm (yep Cm!) or Dm on the B7.
D minor pent on the B7 chord gives you the #9 (D), b5 (F), #5 (G), b7 (A), and b9 (C) - a highly sophisticated jazz choice!:-)
(IOW, it helps to know why these strange choices work - because you are introducing certain valid chord extensions.)
D minor pent will NOT work anywhere else on this tune.