Site-specific introduction of gold-carbenoids by intermolecular oxidation of ynamides or ynol ethers

Abstract

Ynamides and ynol ethers undergo intermolecular gold-catalysed reaction with a nucleophilic oxidant to access metal-carbenoid reactivity patterns. A site-specific oxidation/1,2-insertion cascade is used for a general access to functionalised α,β-unsaturated carboxylic acid derivatives and vinylogous carbimates.

Gold-catalyzed regioselective oxidation of propargylic carboxylates: a reliable access to α-carboxy-α,β-unsaturated ketones/aldehydes

“…By using pyridine N- oxides [1] and later 8-substituted quinoline N -oxides [2] as the external oxidants, this approach permits a safe and efficient access to α-oxo gold carbenes without resorting to the dediazotization strategy [3–5] using hazardous and potentially explosive diazo substrates (Scheme 1). Since then an array of versatile synthetic methods has been developed based on the general approach by us [2,6–12] and other researchers [13–20], thus making it an exciting area for further advancing gold chemistry.…”

Rapid Access to Chroman‐3‐ones through Gold‐Catalyzed Oxidation of Propargyl Aryl Ethers

“…[15e] Several recent works by other research groups also corroborated the intermediacy of gold carbenes. [16] Since metal carbenes in general can be generated via dediazotization, [17] this strategy permits to replace toxic, potentially explosive and sometimes difficult-to-access α-diazo ketones with benign and readily available alkynes in gold carbene chemistry . [18] In the context of chroman-3-one synthesis, we envisioned that this strategy would allow replacing α -diazo- α ′-phenoxy acetones by readily available propargyl aryl ethers (Scheme 1), thereby establishing a succinct, safe and potentially highly efficient route to this class of heterocycles.…”

A Flexible and Stereoselective Synthesis of Azetidin‐3‐ones through Gold‐Catalyzed Intermolecular Oxidation of Alkynes

“…Early in 2010 we showed for the first time [8] that reactive α-oxo gold carbenes [9] could be readily accessed via simple intermolecular oxidation [10] of terminal alkynes, [11] therefore allowing substitution of toxic α-diazo ketones with benign and readily available alkynes (Scheme 1). This approach was later applied to the preparation of oxetan-3-ones from easily available propargyl alcohols.…”