Modular Synthesis of Stereodefined Benzocyclobutene Derivatives via Sequential Cu- and Pd-Catalysis

Benzocyclobutenes (BCBs) are of growing interest in materials and medicinal chemistry, although general routes for their provision remain underexplored. A modular, divergent, stereoselective Cu- Pd-catalyzed assembly/cyclization sequence allows the synthesis densely functionalized BCBs, from readily accessible imine, allene, diboron precursors. Preliminary results have identified enantioselective conditions our protocol highlighted, example, its applicability to BCB-containing peptides. By simple variation experimental or substrate modification, strategy was expanded deliver indoline quinoline derivatives, suitable further manipulations.