Synthesis of thioxanthones through formal C-H thiolation of benzoic acid esters and Acid-mediated Direct Cyclization
An efficient thioxanthone synthesis from benzoic acid esters is disclosed. Various thioxanthones were prepared by iridiumcatalyzed C-H borylation of benzoic acid esters followed by copper-catalyzed deborylthiolation and direct acid-mediated cyclization. We also achieved a synthesis of benzo-fused thioxanthones through a transformation of an aryne intermediate having an ester moiety.
N,B-bidentate boryl ligand-supported iridium catalyst for efficient functional-group-directed C-H borylation
Convenient silylborane precursors for introducing N,B-bidentate boryl ligands onto transition metals were designed, prepared, and employed in ready formation of irdium(IIl) complexes via Si-B oxidative addition. A practical, efficient catalytic ortho-borylation reaction of arenes with a broad range of directing groups was developed using an in situ generated catalyst from the silylborane preligand 3c and [IrCl(COD)]2.
Selenium-catalyzed C(sp3)-H acyloxylation: Application in the expedient synthesis of isobenzofuranones
Oxidative Se-catalyzed C(sp3)-H bond acyloxylation has been used to construct a diverse array of isobenzofuranones from simple ortho-allyl benzoic acid derivatives. The synthetic procedure employs mild reaction conditions and gives high chemoselectivity enabled by an inexpensive organodiselane catalyst. The presented approach offers a new synthetic pathway toward the core structures of phthalide natural products.
Kr?tzschmar, Felix,Kassel, Martin,Delony, Daniel,Breder, Alexander
p. 7030 - 7034
(2015/05/05)
Silyl phosphorus and nitrogen donor chelates for homogeneous ortho borylation catalysis
Ir catalysts supported by bidentate silyl ligands that contain P- or N-donors are shown to effect ortho borylations for a range of substituted aromatics. The substrate scope is broad, and the modular ligand synthesis allows for flexible catalyst design.
Ghaffari, Behnaz,Preshlock, Sean M.,Plattner, Donald L.,Staples, Richard J.,Maligres, Peter E.,Krska, Shane W.,Maleczka, Robert E.,Smith, Milton R.
supporting information
p. 14345 - 14348
(2014/12/10)
Directed ortho borylation of functionalized Arenes catalyzed by a silica-supported compact phosphine-iridium system