Ni-Catalyzed Three-Component Alkene Carboacylation Initiated by Amide C–N Bond Activation

Abstract

The nickel-catalyzed intermolecular carboacylation of alkenes with amides and tetraarylborates is presented. Bicyclic alkenes are readily functionalized with a variety of N-benzoyl-N-phenylbenzamides and triarylboranes, which are generated in situ from the corresponding tetraarylborates, to synthesize ketone products in up to 91% yield. Preliminary mechanistic studies suggest that migratory insertion precedes transmetalation and that reductive elimination is the turnover-limiting step. These reactions occur with excellent chemoselectivity and diastereoselectivity in the absence of a directing/chelating group and further demonstrate amides as practical acyl electrophiles for alkene dicarbofunctionalization reactions.

Nickel‐CatalyzedDicarbofunctionalization of Alkenes†

“…[ 46‐47 ] In 2019, the Stanley group developed a nickel‐catalyzed acylarylation of norbornene derivatives with amides and tetraarylborates triggered by activation of an amide bond (Scheme 3c). [ 48 ]…”

Recent developments in nickel-catalyzed intermolecular dicarbofunctionalization of alkenes

“…8). 25 The transformation was found to take place under the action of 10 mol% Ni(cod) 2 and 2 equiv. of H 3 BO 3 , tolerating a wide array of norbornene-type alkenes and…”

Recent Advances in Nickel-Catalyzed Three-Component Difunctionalization of Unactivated Alkenes

“…Very recently, Stanley and co-workers successfully extended this catalytic system to a real three-component mode, achieving the intermolecular carboacylation of norbornene with benzamides and tetraarylboranes via nickelcatalyzed C-N activation (Scheme 3). 4 A variety of N-benzoyl-N-phenylbenzamides were employed as competent electrophilic acylating agents, delivering 1,2-arylacylated products in high yields. A key step in the proposed mechanism for this three-component carboacylation involved the migratory insertion of acyl-Ni(II) into norbornene followed by transmetalation with aryl borane.…”

“…8 This reaction demonstrated good compatibility with aryl halides, arylzinc reagents and terminal alkenyl imines, furnishing ,-diaryl ketones with excellent regioselectivity after simple workup. Specifically, the synergistic use of cationic metal salts (such as AgBF 4 and Cu(MeCN) 4 BF 4 ) was important to achieve the desired 1,2-difunctionalization reactivity, probably because they could promote the abstraction of halides to generate cationic Ni(II) species, which could facilitate the subsequent migratory insertion and transmetalation steps.…”