A copper‐catalyzed tandem process to generate chiral cyclobutene derivatives has been developed. It is based on an enantioselective conjugate addition or reduction of a cyclobutenone and sequential trapping with a chlorophosphate in a one‐pot process. These phosphates are stable under mildly acidic conditions and serve as good electrophiles in Negishi coupling reactions.

https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201913825