Rh(i)-catalyzed [4 + 2]-annulation of furan-fused cyclobutanones with alkynes and synthetic applications

Abstract

Fully-substituted aromatic skeletons have received increasing interest from the synthetic chemistry, pharmaceutical and material sciences. However, diversity-oriented construction of these molecules remains challenging due to the lack of effective synthetic building blocks. Herein, we report a Rh(I)-catalyzed [4 + 2]-annulation reaction of alkynes with furan-fused cyclobutanones (FCBs) for the expeditious assembly of fully-substituted o-quinone methide (o-QM) precursors containing a furan-fused motif under mild conditions. These products could be served as practical and robust synthons for the synthesis of fully-substituted phenols with broad functional group compatibility.