  We study the Mott transition, antiferromagnetism and superconductivity in
layered organic conductors using Cellular Dynamical Mean Field Theory for the
frustrated Hubbard model. A d-wave superconducting phase appears between an
antiferromagnetic insulator and a metal for $t^{\prime}/t=0.3-0.7 $, or between
a nonmagnetic Mott insulator (spin liquid) and a metal for $t^{\prime}/t\geq
0.8$, in agreement with experiments on layered organic conductors including
$\kappa $-(ET)$_{2}$Cu$_{2}$(CN)$_{3}$. These phases are separated by a strong
first order transition. The phase diagram gives much insight into the mechanism
for d-wave superconductivity. Two predictions are made.
