title: Acylsilanes in rhodium(III)-catalyzed directed aromatic C-H alkenylations and siloxycarbene reactions with C-C double bonds.
abstract: Acylsilanes are known to undergo a 1,2-silicon-to-oxygen migration under thermal or photochemical conditions to form siloxycarbenes. However, there are few reports regarding the application of siloxycarbenes in organic synthesis and surprisingly, their reaction with CC double or triple bonds remains virtually unexplored. To facilitate such a study, previously inaccessible aromatic acylsilanes containing an ortho-tethered CC double bond were identified as suitable substrates. To access these key intermediates, we developed a new synthetic method utilizing a rhodium-catalyzed oxidative Heck-type olefination involving the application of an acylsilane moiety as a directing group. When exposed to visible-light irradiation, the ortho-olefinated acylsilanes underwent a smooth intramolecular cyclization process to afford valuable indanone derivatives in quantitative yields. This result paves the way for the development of new transformations involving siloxycarbene intermediates.
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany).
authors.forename: Peter
authors.initials: P
authors.lastname: Becker
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Priebbenow
authors.forename: Ramona
authors.initials: R
authors.lastname: Pirwerdjan
authors.forename: Carsten
authors.initials: C
authors.lastname: Bolm
keywords: C-H functionalization; acylsilanes; carbenes; photochemistry; rhodium catalysis