Synthesis of Substituted Naphtho‐Ferrocenes via a Gold(I)‐Catalyzed Intramolecular 6‐endo‐Dig Cyclization

Abstract

A novel series of naphtho-ferrocene derivatives were synthesized in high yields by an efficient gold-catalyzed intramolecular 6-endo-dig cyclization strategy. The salient features of this reaction include easy operation, broad substrate scope, high yields, mild conditions and it works well in wet solvent under air at room temperature.

Planar Chiral Pseudo‐Isocoumarins by Copper Catalysed Desymmetrisation

“…Unsymmetrically substituted ferrocenes have planar chirality, so when an isocoumarin ring is fused to a cyclopentadienyl ligand of ferrocene, issues about enantioselective synthesis are unavoidable, especially since for development of a new drug candidate, enantiopure compounds are much preferred to racemates when assessing bioactivity. The synthesis of planar chiral ferrocenes, usually by directed lithiation mediated by a chiral directing group, [18–23] is of ongoing interest while metal catalysed enantioselective cyclisations on activated alkynyl ferrocenes and desymmetrisation strategies for the installation of planar chirality are becoming more frequently used [24–29] . We report here a new method of asymmetric synthesis of isocoumarin‐fused ferrocenes, based on our interest in the desymmetrisation of prochiral ferrocene diynes [30] by asymmetric click chemistry [31] …”

“…The synthesis of planar chiral ferrocenes, usually by directed lithiation mediated by a chiral directing group, [18][19][20][21][22][23] is of ongoing interest while metal catalysed enantioselective cyclisations on activated alkynyl ferrocenes and desymmetrisation strategies for the installation of planar chirality are becoming more frequently used. [24][25][26][27][28][29] We report here a new method of asymmetric synthesis of isocoumarin-fused ferrocenes, based on our interest in the desymmetrisation of prochiral ferrocene diynes [30] by asymmetric click chemistry. [31]…”