Abstract
Benzannulation strategies that attach a planar arene ring to cyclic, saturated, three-dimensional bridged motifs are becoming valuable for drug discovery. Herein, a Lewis acid-catalyzed [4+3] annulation of in situ-generated o-QMs with bicyclo[1.1.0]butanes is developed. Reaction modulation further leveraged a telescoped [4+2] annulation of o-QMs with the in situ-formed cyclobutanes, leading to diversified sp(3)-rich oxabicyclic architectures. Overall, this study expands the scope for a new bioisosteric space for medicinal chemistry.