Gold‐Catalyzed Oxidative Cyclizations of cis‐3‐En‐1‐ynes To Form Cyclopentenone Derivatives

Abstract

Scheme 3. Deuterium-labeling experiments.Scheme 4. The reaction using diazocarbonyl.Scheme 5. The nature of CÀH insertion.Scheme 6. A plausible reaction mechanism.

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.…”

Divergent Regio‐ and Stereoselective Gold‐catalyzed Synthesis of α‐Fluorosulfones and β‐Fluorovinylsulfones from Alkynylsulfones

“…Reaction of alkynylsulfone 1 ac (R=methyl, Ar= o ‐tolyl) gave a very interesting, carbene insertion product 6 a in very good yield. This result can be attributed to the presence of a reactive benzylic C−H in close proximity to the generated gold carbene intermediate . Nucleophilic fluoromethylation and subsequent sulfone elimination of 3 n gives fluoroalkene 7 in very good yield .…”

Iron-catalyzed decarboxylative alkenylation of cycloalkanes with arylvinyl carboxylic acids via a radical process

“…Among all these C–H functionalization methods, the direct C(sp 3 )–H functionalization attracts particular attention due to its low reactivity and challenging activation [9–11]. In previous studies, numerous transition-metal-catalyzed processes, such as Pd [12–18], Cu [19–23], Ru [24–27], Rh [28–31], Co [32–34], Au [35–36], Ir [37–39], Fe [40–43] and other metals [44–47], have been developed for sp 3 C–H activation reactions. Additionally, metal-free methodologies, which use TBHP, PhI(OAc) 2 , TBAI, I 2 or Lewis/Brønsted acids, have also been employed for cross-dehydrogenative coupling reactions [48–57].…”