Cobalt-Catalyzed Allylation of Amides with Styrenes Using DMSO as Both the Solvent and the α-Methylene Source

Abstract

An efficient synthesis of privileged allylic amines has been developed via cobalt-catalyzed allylation of amides with styrenes, in which DMSO was used as both the solvent and the α-methylene source. This transformation features high yields, and selectivity for the (E)-isomer of the linear product. Through the experimental and computational investigations, a sequential K 2 S 2 O 8 -mediated oxidative coupling/cobalt-assisted regioselective alkene insertion/β−H elimination/alkene dissociation/hydride transfer process has also been deduced.

One‐pot Cascade Reaction for the Synthesis of Phenanthridines via Suzuki Coupling/C−H Oxidation/Aromatization

“…Apart from Cu(OTf) 2 , other catalysts such as TfOH, TsOH, K 2 CO 3 , Et 3 N, FeCl 3 , ZnCl 2 , Cu(OAc) 2 and Pd(OAc) 2 at 10 mol% were also employed in the protocol and it was clear that the most efficient catalyst in the present catalytic system was Cu(OTf) 2 (entry 7 vs [11][12][13][14][15][16][17][18]. Further investigation of the amount of the catalyst indicated that 10 mol% was an ideal amount (entry 7 vs [19][20]. The effect of reaction temperatures on the yields was then investigated.…”

“…[18] Very recently, Yi et al reported cobalt-catalyzed allylation of amides using DMSO as both the solvent and the methylene source. [19] Talukdar demonstrated Ru(II) photo-catalyzed synthesis of acetals from alcohols by DMSO. [20] In addition, a cascade [4 + 1] annulation of sulfonium salts for synthesis of polyfunctional furans using DMSO as one carbon source was established.…”

“…Very recently, Yi et al. reported cobalt‐catalyzed allylation of amides using DMSO as both the solvent and the methylene source [19] . Talukdar demonstrated Ru(II) photo‐catalyzed synthesis of acetals from alcohols by DMSO [20] .…”

Metal‐Free Synthesis of 2‐Aryl Quinazolines via Tandem C−H/N−H Bond Functionalization

“…Meanwhile, DMSO dehydrates to form intermediate 1 with an S=C bond [30a,b,f] . 1 a then undergoes a nucleophilic addition reaction with 1 to produce intermediate 2 , [30e] and simultaneously loses methyl mercaptan to obtain imine 3 [30f] as identified by high performance liquid chromatography‐mass spectrometry (LC‐MS) (see support information). Next, 3 [30f] is protonated to form a carbenium ion intermediate 4 [23] .…”

Base-Mediated Anti-Markovnikov Hydroamidation of Vinyl Arenes with Arylamides

“…The construction of suitably functionalized amide frameworks is useful in many industrial and natural product syntheses . In the past few decades, many traditional approaches for transition-metal-catalyzed hydroamination of N -heterocycles and primary/secondary amines with alkynes and alkenes have been well explored. − Base-mediated nucleophilic addition of heterocycles as well as amine moieties has also been known from many renowned reactions reported in the literature. , However, due to the formation of highly stable resonating structures and poor nucleophilicity hydroamination of amides is still challenging. − …”