N-Acyl-5,5-Dimethylhydantoins: Mild Acyl-Transfer Reagents for the Synthesis of Ketones Using Pd–PEPPSI or Pd/Phosphine Catalysts

Abstract

N-Acyl-hydantoins have emerged as novel acyl-transfer reagents for the synthesis of ketones via selective N−C(O) cleavage. Herein, we report two new protocols for the cross-coupling of N-acyl-5,5-dimethylhydantoins using versatile and readily accessible Pd−PEPPSI or Pd/phosphine catalysts. The acyl Suzuki reactions afford biaryl ketones in good to excellent yields under operationally simple conditions using commercially available, bench-and air-stable twisted N-acyl-hydantoins as acyl donors. The method complements and expands on the previous protocol for the cross-coupling of N-acyl-hydantoins (

Classes of Amides that Undergo Selective N–C Amide Bond Activation: The Emergence of Ground-State Destabilization

“…Thus, N-acyl-hydantoins represent another class of electronically disconnected amides. The presence of the free NH group on hydantoin is tolerated in N−C(O) activation as shown by our and Zeng's groups in Suzuki−Miyaura cross-coupling using Pd−NHCs or Pd− phosphines 61,62.…”

α-Diimine-based conjugated microporous polymers as heterogeneous ligands for highly efficient palladium-catalyzed direct C–H arylations

“…[50][51][52][53][54][55][56] CMP materials have been applied in many areas such as gas adsorption/separation/storage, [57][58][59][60] energy storage, [61][62][63][64][65] molecule recognition/sensors, [66][67][68][69] light emitting/harvesting, [70][71][72][73][74] and heterogeneous catalysis. [75][76][77][78][79][80][81][82][83] Based on our group's longstanding interest in the field of heterogeneous porous organic catalysis [84][85][86][87][88][89][90] and homogeneous Pd-ligand catalysis, 36,[91][92][93][94][95][96][97]…”

“…50–56 CMP materials have been applied in many areas such as gas adsorption/separation/storage, 57–60 energy storage, 61–65 molecule recognition/sensors, 66–69 light emitting/harvesting, 70–74 and heterogeneous catalysis. 75–83 Based on our group's longstanding interest in the field of heterogeneous porous organic catalysis 84–90 and homogeneous Pd–ligand catalysis, 36,91–99 we observed that a conjugated microporous polymer (CMP) when incorporated with 1,3,5-tris(4-ethynylphenyl)benzene served as an effective heterogeneous catalysis matrix in Pd-catalyzed transformations. 83,100,101…”

Aminomethylpyridinequinones as new ligands for PEPPSI-type complexes

“…[4][5][6] The parent complex was obtained from the reaction between PdCl2, a bulky NHC (2,6-diisopropylphenylimidazolium chloride-IPr), and 3-chloropyridine under atmospheric conditions. It is not only exceptionally stable outside an inert atmosphere but also can be treated as a universal catalyst for the majority of cross-coupling reactions 7,8 including Suzuki−Miyaura coupling of esters 9 or amides 10 Since the introduction of this catalyst to the organic chemist's toolbox, Organ and others have been working on its structural modifications to reach even higher activity and selectivity in difficult coupling reactions (Figure 2). First, more bulky aryl substituents, like, e.g., 2,6-diisopentylphenyl, were utilized.…”