[ku85]

Hi,

I'm a  newbie here
I have a question for you regarding the Mitsunobu reaction
How is the mechanism of the reaction in presence of diphenylphosphoril azide?

thanks for the help

[TheUnassuming]

Check out the basic mechanism on wikipedia. 
DPPA is simply an N₃^- source.  The mitsunobu reaction can be done with a fairly diverse set of nucleophiles as long as the pKa of the compound (R group in the wiki article) is in the correct range.  R can be various carboxylates as well as a number of azide/carbamate derivatives.