Background Gold Catalysis

Characteristics of gold complexes:

The «noble metal» conception of gold has hindered the development of gold catalysis in chemistry, as gold compounds were previously expected to be catalytic inactive and too expensive to be used as catalysts.

Advantages:

• high oxidation potential of gold(I) to gold(III);  allows reactions without air exclusion;
• gold catalysts are alkynophilic (C:::C) but not oxophilic (O); coordinate preferentially to C-C multiple bonds, tolerate the presence of heteroatoms (e.g. Nu, O, N) allow reactions without moisture exclusion;
• LAu⁺ is isolobal to H⁺ and LHg²⁺; allows less vigorous conditions;
• gold catalysis demonstrates highly substrate dependent reaction manifolds;
  gives highly regio- / chemo-selective reactions;
• gold catalysed reactions provide efficient access to diverse structures from simple starting materials
• relatively non-toxic

Typical reaction pathway for nucleophilic attack at alkynes by gold(I)-catalysed activation of triple bonds

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Typical gold(I) (pre)catalysts:

We are exploring gold(I) catalysis in organic synthetic chemistry;
the following topics have been studied:

• Gold catalysed cyclizations of alkynes
• Gold(I) catalysed cycloaddition reactions of propargyl substrates
• Vinylamide dimerization; "hidden acid" catalysis
• Homopropargyl acetal cyclization - fluorination