Sequential Friedel–Crafts-Type α-Amidoalkylation/Intramolecular Hydroarylation: Distinct Advantage of Combined Tf₂NH/Cationic LAu(I) as a Consecutive or Binary Bicatalytic System

Abstract

The combined use of Tf2NH and L(Au)(+)X(-) as a dual or binary catalytic system clearly improves the efficiency and enlarges the scope of the tandem intermolecular Friedel-Crafts α-amidoalkylation/intramolecular hydroarylation sequence, compared to an "all gold" multicatalysis approach.

Autotandem Catalysis: Inexpensive and Green Access to Functionalized Ketones by Intermolecular Iron‐Catalyzed Amidoalkynylation/Hydration Cascade Reaction via N‐Acyliminium Ion Chemistry

“…Secondary exocyclic acetoxylactam 5 a were subjected to alkynylation reaction giving the products 6 a, 6 b, and 6 c in 90 %, 85 %, and 93 % isolated yields, respectively (Scheme 3). As anticipated from earlier results by our group, acetoxylactam 5 b derived from saccharine [28] surpassed its isoindolone congeners 5 a, and delivered the target products 7 a, 7 b, and 7 c in respectively 78 %, 80 % and 97 % higher isolated yields and a reduced reaction time of 1 h. The use of the exocyclic acetoxylactam pyrrolidine 5 c as a less electrophilic precursor was also effective substrate and was subjected to alkynylation giving 8 a in 57 % yield using 4 equivalents of 3 c and 10 mol% of FeCl 3 . The reaction was also applicable to N-O-acetals substrates with tertiary exocyclic acetoxylactams, [29] as exemplified by the synthesis of 9 a-e derived from acetoxylactam 5 d. The products were isolated in good to excellent yields (60 to 99 %) (Scheme 3).…”

Novel Hybrid Prins/Aza‐Prins Oxocarbenium/N‐Acyliminium Cascade: Expedient Access to Complex Indolizidines

“…With the proof of concept established, we next endeavored to extend the method (Scheme ). As anticipated from earlier results in our group, the methoxy aminal 2 e derived from saccharine surpassed its isoindolone congeners 2 b , c , and delivered the target products 5 b and 5 a in higher yields and a reduced reaction time (76 % and 67 %, 1 h). We were also pleased to show that the reaction has the potential to accommodate aminal substrates with a tertiary C(sp 3 ) close to the reaction center, as exemplified by the synthesis of product 6 derived from ( L )‐malic acid, which was isolated in a yield similar to the succinimidic series (32 %) as an inseparable mixture of two diastereoisomers (2:1 ratio).…”

Nickel(0)‐Catalyzed N‐Allylation of Amides and p‐Toluenesulfonamide with Allylic Alcohols under Neat and Neutral Conditions

“…Product 8f , allylated on the amino group, was obtained as a mixture with diallylated (on the amino and amido groups) compound 8g , thus demonstrating the higher reactivity of the aniline nitrogen atom relative to that of the amide group (Table , Entry 4). A low yield of product was obtained using phthalimide, a widely used reactant in the chemistry of N ‐acyliminium ions (Table , Entry 5) . However, p ‐toluenesulfonamide ( 7f ) was found to efficiently react with allyl alcohol yielding selectively diallylated 8i (Table , Entry 6).…”