Benzocyclobutenone synthesis exploiting acylsilanes as photofunctional directing groups

Abstract

The visible-light irradiation of acylsilane tethered vinyl ketones promotes an intramolecular Stetter-type reaction via siloxycarbene intermediates. To exploit this unique mode of reactivity, we herein describe the innovative use of acylsilanes as photofunctional directing groups. First, an acylsilane directed ruthenium catalysed C–H olefination reaction was developed to generate benzoylsilanes bearing vinyl ketone functionality. Then, visible-light irradiation initiated the 1,4-conjugate addition of transient siloxycarbene intermediates with pendent vinyl ketones to afford unique benzocyclobutenone scaffolds primed for further synthetic elaboration.