We show that every CR-automorphism of the closure of a Levi degenerate hyperquadric in the projective space extends to a holomorphic automorphism of the projective space.
"Continuation of CR-automorphisms of Levi degenerate hyperquadrics to the projective space." Illinois J. Math. 54 (2) 747 - 752, Summer 2010. https://doi.org/10.1215/ijm/1318598679