Can we reach enlightentment with recreational drugs? Some drugs, like ecstasy, help build empathy and help our mind see things from a different point of view.

What about if meditation is the obsolete ways to see enlightment and perhaps drugs are the easier ways?
From the perspective of the 5th precept then the answer would be no. The fifth precepts states


  I undertake the training rule to abstain from fermented drink that
  causes heedlessness


But I've often seen this rendered as 


  I undertake the training rule to abstain from intoxicating substances


While the fact that it breaks the precept might leave you unconvinced these precepts are viewed as training principles i.e. it is the best way to achieve liberation or enlightenment. So in many traditions intoxicants are not seen as an aide to liberation.

Also the point of the Buddhist path is to see things as they really are. It's difficult to see how one might see things as they really are when one's mental processes are been influenced by recreational drugs of any sort. Reality is difficult enough as it is without dulling, altering or confusing the six senses (I'm including mind here as one of the senses).

The founder of the the sangha that I practice with, Sangharakshita, has taken psychedelic drugs on a couple of occasions to see if there are commonalities with the Buddhist path. From his perspective there wasn't though I believe he found the experience interesting. I have to say this was a controversial action by an often controversial figure. I have never heard any recommendations from him to try this approach so this would be another reason that I would personally discount recreational drug use as an insight practice.

As an aside, the beatnik guru Alan Watts (another contraversial figure) had a more sympathetic attitude to this approach. The most famous quote (which I will include with a little context) is


  Psychedelic experience is only a glimpse of genuine mystical insight,
  but a glimpse which can be matured and deepened by the various ways of
  meditation in which drugs are no longer necessary or useful. If you
  get the message, hang up the phone. For psychedelic drugs are simply
  instruments, like microscopes, telescopes, and telephones. The
  biologist does not sit with eye permanently glued to the microscope,
  he goes away and works on what he has seen


So even Alan Watts wasn't a whole-hearted proponent of this approach. He saw them as a tool at best and in no way replacing meditation or other traditional insight methods. Just to be clear though - Alan Watts wasn't a traditional Buddhist if he was one at all so this comment though interesting has probably limited relevance to this site. Please see it as a footnote to this answer.