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, and stereoselective Cu- and Pd-catalyzed assembly/cyclization sequence allows the synthesis of densely functionalized BCBs, from readily accessible imine, allene, and diboron precursors. Preliminary results have identified enantioselective conditions for our protocol and high-lighted, for example, its applicability to the synthesis of BCB-containing peptides. By simple variation of experimental conditions or substrate modification, our strategy was expanded to deliver indoline and quinoline derivatives, suitable for further manipulations.

Automated summary

A new synthetic method has been developed in this study to efficiently and selectively synthesize densely functionalized BCBs compounds, which can also be extended to the synthesis of other organic derivatives. The results provide new ideas and technical support for the synthesis of BCB compounds with specific functions.