Access to substituted cyclobutenes by tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition of dipropargylphosphonates under Ag/Co relay catalysis

Qijian Ni; Xiaoxiao Song; Chin Wen Png; Yongliang Zhang; Yu Zhao

doi:10.1039/d0sc02972f

Access to substituted cyclobutenes by tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition of dipropargylphosphonates under Ag/Co relay catalysis

Chem Sci. 2020 Oct 16;11(45):12329-12335. doi: 10.1039/d0sc02972f.

Authors

Qijian Ni^{1

2}, Xiaoxiao Song^{1

2}, Chin Wen Png³, Yongliang Zhang³, Yu Zhao^{2

4}

Affiliations

¹ Key Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecule-Based Materials (State Key Laboratory Cultivation Base), College of Chemistry and Materials Science, Anhui Normal University Wuhu 241002 Anhui China.
² Department of Chemistry, National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore zhaoyu@nus.edu.sg.
³ Centre for Life Sciences, National University of Singapore #03-09, 28 Medical Drive 117456 Singapore miczy@nus.edu.sg.
⁴ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Binhai New City Fuzhou 350207 China.

Abstract

We present herein an unconventional tandem [3,3]-sigmatropic rearrangement/[2 + 2] cycloaddition of simple dipropargylphosphonates to deliver a range of bicyclic polysubstituted cyclobutenes and cyclobutanes under Ag/Co relay catalysis. An interesting switch from allene-allene to allene-alkyne cycloaddition was observed based on the substitution of the substrates, which further diversified the range of compounds accessible from this practical method. Significantly, preliminary biological screening of these new compounds identified promising candidates as suppressors of cellular proliferation.