Gold­(I) complexes featuring Z-type ligands introducing electron-withdrawing groups (EWG), Au­(DPBF)Cl (4a) and Au­(DPBCl)Cl (4b) (DPB = diphosphine-boron), have been synthesized and structurally characterized. These studies suggest that increasing the electron-withdrawing properties of the boron phenyl substituent only results in minor structural changes of the gold complexes. These complexes can be converted into Au­(DPBF)­SbF6 and Au­(DPBCl)­SbF6 by treatment of 4a,b with AgSbF6. The cationic complexes show interesting catalytic properties and readily promote the cyclization of yne-diols into unprecedented dioxabicyclo[3.2.2] derivatives.

The metal‐catalyzed carboxylation of propargylamines with aerial CO2 at room temperature to form 5‐methyleneoxazolidin‐2‐one derivatives has been developed. In this reaction, the catalyst [Au(dpbF)]X featuring a Z‐type ligand gave the best results, presumably due to the σ‐acceptance of the borane atom.

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The synthesis of 2,2-dimethyloxepane frameworks based on the 7-endo-trig cyclization of ene-diol using a catalytic amount of metal catalysts (Au, Ag) or Brønsted acid (TfOH) has been developed. Also, the spirotype dioxabicyclic products were also derived from the diene-diols. For the condition using metal catalysts, the cyclization selectively reacted between the 1,1,3-trisubstituted alkenes and alcohols to form the 2,2-dimethyloxepane frameworks. On the other hand, the TfOH reacted with not only the 1,1,2-trisubstituted alkene, but also the 1-substituted and 1,2-disubstituted alkenes providing the corresponding cyclic ethers, which is quite different from the conditions of the metal catalysts.