I've been searching the literature for some time to try and find any conditions or examples of a reaction where an α,β-unsaturated carbonyl has been used as a nucleophile at the alkene, and not as an electrophile.
I realise this probably may not be a possible reaction, but I'm also unsure if my literature searching skills are just poor.
In particular I'm interested in an example where an α,β-unsaturated carbonyl has been used in a Prins or Prins-like reaction where the alkene is the nucleophile. However if anyone knows any examples or sources where an α,β-unsaturated carbonyl has been used as a pi nucleophile at the alkene, this would be of significant help.
Thanks.