A detachable ester bond enables perfect Z-alkylations of olefins for the synthesis of tri- and tetrasubstituted alkenesElectronic supplementary information (ESI) available. See DOI: 10.1039/c5cc03474d

2-Vinyl-substituted phenol and an alpha-bromoester undergo a tandem esterification-alkylation reaction in the presence of a Cu-amine catalyst system to produce benzene-fused lactone. Z -Alkylated styrene is obtained after hydrolysis of the lactone with perfect selectivity. The simple protocol developed in this work opens a new avenue in the multi-substitution chemistry of alkenes. We developed a tandem esterification-intramolecular alkylation reaction catalyzed by a copper catalyst, leading to the formation of a lactone, followed by hydrolysis of the resulting lactone to give Z -alkylated alkenes in good yields with perfect selectivities.