Robin Thicke tried and tried hard to save his
marriage, but it didn't work.
TMZ has
learned Paula Patton has filed for divorce ...
and as for the most important asset in the
marriage ... she wants joint custody.Paula
cites the usual ... irreconcilable differences.
She wants joint legal and physical custody
of their 4-year-old son Julian.

The divorce
was filed in L.A., so there will be no issues
over whether Robin may have strayed. It's
irrelevant.We're also told the divorce is
"harmonious" and there are no real issues
that will cause a conflict.Paula says the date
of separation was February 21.

Source: http://m.tmz.com/2014/10/08/robin-thicke-paula-patton-divorce-files-joint-custody/