  Mott insulator superconductor transition, via pressure and no external
doping, is studied in orbitally non degenerate spin-\half systems. It is
presented as another RVB route to high \tc superconductivity. We propose a
`strong coupling' hypothesis which helps to view first order Mott transition as
a self doping process that also preserves superexchange on metal side . We
present a generalized t-J model where a conserved $N_0$ doubly occupied ($e^-$)
sites and $N_0$ empty sites ($e^+$) hop in the background of $N - 2 N_0$ singly
singly occupied (neutral) sites in a lattice of N sites. An equivalence to the
regular t-J model is made and some old and new systems are predicted to be
candidates for pressure induced high \tc superconductivity.
