Oxidative Addition of Alkenyl and Alkynyl Iodides to a Au^I Complex

Abstract

The first isolated examples of intermolecular oxidative addition of alkenyl and alkynyl iodides to AuI are reported. Using a 5,5′‐difluoro‐2,2′‐bipyridyl ligated complex, oxidative addition of geometrically defined alkenyl iodides occurs readily, reversibly and stereospecifically to give alkenyl‐AuIII complexes. Conversely, reversible alkynyl iodide oxidative addition generates bimetallic complexes containing both AuIII and AuI centers. Stoichiometric studies show that both new initiation modes can form the basis for the development of C−C bond forming cross‐couplings.

Oxidative additions of alkynyl/vinyl iodides to gold and gold-catalyzed vinylation reactions triggered by the MeDalphos ligand

“…along with extended reaction times (1 h), and tends to form Au( i )/Au( iii ) bimetallic complexes. 13 …”

“…The absence of J PC coupling supports cis relationship between the vinyl and PAd 2 groups at gold while the large 3 J HH coupling constant (14.5 Hz) indicates that the trans geometry of the C C bond is retained. Given that only styrenyl substrates undergo oxidative addition to the (bipyridine)Au(H 2 C CH 2 ) + complex, 13 we were eager to examine the scope of vinyl iodides prone to react with the (P,N)AuCl complex 1 . Gratifyingly, instantaneous and quantitative reactions were observed with the alkyl-substituted substrate 4b , the parent vinyl iodide 4c (oxidative addition takes 3 h in this case), as well as the ester-substituted substrates 4d,e .…”

“…1c ). 13 As for aryl iodides, the reaction is reversible and requires an excess of substrate to isolate the respective Au( iii ) complexes.…”

Fundamental Basis for Implementing Oxidant‐Free Au(I)/Au(III) Catalysis

“…[50] In 2020, Russell reported the first examples of intermolecular oxidative addition of alkenyl and alkynyl iodides to the same Au(I) complex, forming alkenyl Au(III) complexes in a reversible and stereospecific manner for the former (Figure 9c). [54] Hemilabile ligands. In 2016, Bertrand and coworkers reported a (CAAC)AuCl complex (CAAC = Cyclic Alkyl Amino Carbene) bearing a pendant hemilabile imine moiety that helped at stabilizing the Au(III) complex obtained upon oxidative addition of the strained CÀ C bond in biphenylene (Figure 10a).…”

Four-Step One-Pot Catalytic Asymmetric Synthesis of Polysubstituted Tricyclic Compounds: Lipase-Catalyzed Dynamic Kinetic Resolution Followed by an Intramolecular Diels–Alder Reaction

“…More specifically, the DKR of (±)-2 provided optically active esters 3 which underwent the intramolecular Diels-Alder (IMDA) reaction to form optically active tricyclic molecules 4 (Scheme 1b). 10 In these reactions, ketones 1 (~10% yield) were obtained as side products of the in situ racemization. In their related work, Corey et al prepared optically active allyl alcohols 2 by the enantioselective reduction of dienones 1, and synthesized similar compounds 4 through an esterification reaction followed by an IMDA reaction.…”