Browsing by Author "Simon, Martin"

Abstract A highly atroposelective (up to 97 % ee ) Au‐catalyzed synthesis of 1,1′‐binaphthalene‐2,3′‐diols is reported starting from a range of substituted benzyl alkynones. Essential for the achievement of high enantioselectivity during the key assembly of the naphto‐3‐ol unit is the use of TADDOL‐derived α‐cationic phosphonites as ancillary ligands. Preliminary results demonstrate that the transformation of the obtained binaphthyls into axially chiral monodentate phosphines is possible without degradation of enantiopurity.

Abstract The evaluation of the pentafluorocyclopropyl group as a chemotype in crop protection and medicinal chemistry has been hampered in the past by the lack of suitable methodologies that enable the practical incorporation of this moiety into advanced synthetic intermediates. Herein, we report the gram‐scale synthesis of an unprecedented sulfonium salt, 5‐(pentafluorocyclopropyl)dibenzothiophenium triflate, and its use as a versatile reagent for the photoinduced C−H pentafluorocyclopropylation of a broad series of non‐previously functionalized (hetero)arenes through a radical mediated mechanism. The scope and potential benefits of the protocol developed are further demonstrated by the late‐stage introduction of the pentafluorocyclopropyl unit into biologically relevant molecules and widely used pharmaceuticals.

Abstract The regioselective functionalization of heptacyclo[6.6.0.0 2,6 .0 3,13 .0 4,11 .0 5,9 .0 10,14 ]tetradecane (HCTD) under photocatalytic conditions is described. The protocols developed share an initial photo‐triggered hydrogen atom abstraction that regioselectively generates the necessary HCTD‐radical preferentially at position 1‐, they employ no excess of the precious cage carbocycle, and enable the straightforward access to a broad variety of 1‐(alkyl, aryl, or sulfinyl) HCTDs in moderate but still synthetically useful yields. The scope and limitations of each transformation are also discussed.