2689-59-0Relevant academic research and scientific papers
Photoinduced remote heteroaryl migration accompanied by cyanoalkylacylation in continuous flow
Duan, Xiu,Guo, Kai,Liu, Jie,Ma, Can-Liang,Qin, Long-Zhou,Qiu, Jiang-Kai,Sun, Qi,Wu, Meng-Yu,Yuan, Xin,Zhang, Xin-Peng,Zhu, Shan-Shan
supporting information, p. 8916 - 8921 (2021/11/27)
A photoinduced 1,4-heteroaryl migration from a carbon center to a nitrogen center accompanied by a cyanoalkylacylation of heterocyclic-substituted azidyl homoallylic alcohols and cycloketone oxime esters has been described. This simple and powerful protoc
Evaluation of Cyclic Amides as Activating Groups in N-C Bond Cross-Coupling: Discovery of N-Acyl-δ-valerolactams as Effective Twisted Amide Precursors for Cross-Coupling Reactions
Rahman, Md. Mahbubur,Pyle, Daniel J.,Bisz, Elwira,Dziuk, B?a?ej,Ejsmont, Krzysztof,Lalancette, Roger,Wang, Qi,Chen, Hao,Szostak, Roman,Szostak, Michal
, p. 10455 - 10466 (2021/07/31)
The development of efficient methods for facilitating N-C(O) bond activation in amides is an important objective in organic synthesis that permits the manipulation of the traditionally unreactive amide bonds. Herein, we report a comparative evaluation of a series of cyclic amides as activating groups in amide N-C(O) bond cross-coupling. Evaluation of N-acyl-imides, N-acyl-lactams, and N-acyl-oxazolidinones bearing five- and six-membered rings using Pd(II)-NHC and Pd-phosphine systems reveals the relative reactivity order of N-activating groups in Suzuki-Miyaura cross-coupling. The reactivity of activated phenolic esters and thioesters is evaluated for comparison in O-C(O) and S-C(O) cross-coupling under the same reaction conditions. Most notably, the study reveals N-acyl-δ-valerolactams as a highly effective class of mono-N-acyl-activated amide precursors in cross-coupling. The X-ray structure of the model N-acyl-δ-valerolactam is characterized by an additive Winkler-Dunitz distortion parameter ?(τ+χN) of 54.0°, placing this amide in a medium distortion range of twisted amides. Computational studies provide insight into the structural and energetic parameters of the amide bond, including amidic resonance, N/O-protonation aptitude, and the rotational barrier around the N-C(O) axis. This class of N-acyl-lactams will be a valuable addition to the growing portfolio of amide electrophiles for cross-coupling reactions by acyl-metal intermediates.
Asymmetric Transfer Hydrogenation of Aryl Heteroaryl Ketones using Noyori-Ikariya Catalysts
Zheng, Ye,Martinez-Acosta, Jaime A.,Khimji, Mohammed,Barbosa, Luiz C. A.,Clarkson, Guy J.,Wills, Martin
, p. 4384 - 4391 (2021/08/23)
A range of ketones flanked by a combination of an aromatic and a heterocyclic ring (furan, thiophene, N-methylimidazole) were reduced under asymmetric transfer hydrogenation (ATH) conditions. Using a range of [(arene)Ru(TsDPEN)Cl] precatalysts, including tethered derivatives, the reduction enantioselectivity was high (up to 99 % ee) in cases where the aromatic ring contained an ortho-substituent. The enantioselectivity is influenced by a combination of steric and electronic factors which for the furan and thiophene series, follow literature precedents. In the case of the N-methylimidazole-containing ketones, an unexpected switch in enantioselectivity took place upon variation of the opposing aromatic group. Pyrrole- containing ketones were resistant to reduction. This study demonstrates the asymmetric transfer hydrogenation (ATH) of a range of hindered heterocyclic ketones, in high conversion and ee, using Noyori-Ikariya catalysts.
Direct Access to α,β-Unsaturated Ketones via Rh/MgCl2-Mediated Acylation of Vinylsilanes
Chen, Zi-Yan,Deng, Xue-Zu,Song, Yang,Xue, Fei,Yamane, Motoki,Yue, Yan-Ni
, p. 12693 - 12704 (2021/09/28)
We report herein the facile and practical construction of α,β-unsaturated ketones via rhodium-catalyzed direct acylation of vinylsilanes with readily available and abundant carboxylic acids. This protocol features access to a diverse array of synthetically useful functionalities with moderate to excellent yields. More importantly, the late-stage functionalization of pharmaceuticals was also realized with synthetically useful yield.
Novelmeta-benzothiazole and benzimidazole functionalised POCOP-Ni(ii) pincer complexes as efficient catalysts in the production of diarylketones
Castillo-García, Antonio A.,González-Sebastián, Lucero,Lomas-Romero, Leticia,Hernandez-Ortega, Simon,Toscano, Ruben A.,Morales-Morales, David
, p. 10204 - 10216 (2021/06/18)
The synthesis of four novel non-symmetric Ni(ii)-POCOP pincer complexesmeta-functionalized with either benzothiazole or benzimidazole at the central aryl ring is described. All complexes were fully characterised in solution by various analytical techniques and the molecular structures in the solid state of complexes1b,2aand2bwere unequivocally determined by single crystal X-ray diffraction analysis. In addition, the Ni(ii)-POCOP pincer complexes were efficiently used as catalysts in the synthesis of diarylketones by cross-coupling reactions of functionalized benzaldehydes and boronic acid derivatives under relatively mild conditions. An important aspect of this transformation is the dependence on the steric properties of the donor groups (OPR2) of the pincer ligands, the more active compounds having the phosphinitos bearing isopropyl groups (1aand2a) than those containingtert-butyl substituents (1band2b).
Water Phase, Room Temperature, Ligand-Free Suzuki–Miyaura Cross-Coupling: A Green Gateway to Aryl Ketones by C–N Bond Cleavage
Zhang, Yuqi,Wang, Zijia,Tang, Zhao,Luo, Zhongfeng,Wu, Hongxiang,Liu, Tingting,Zhu, Yulin,Zeng, Zhuo
, p. 1620 - 1628 (2020/03/04)
We report herein a green strategy for synthesis of aryl ketones from twisted amides by using Pd(OAc)2 as catalysts. This method shows high functional group tolerance to offer a variety of ketones in good yields under mild conditions (up to 94 %). Notably, this methodology demonstrates the first water phase, room temperature, ligand-free Suzuki–Miyaura coupling through C–N bond cleavage, which is environmentally friendly and might facilitate the development of amide based green chemistry.
N-Acylcarbazoles and N-Acylindoles: Electronically Activated Amides for N-C(O) Cross-Coupling by Nlpto Ar Conjugation Switch
Buchspies, Jonathan,Rahman, Md. Mahbubur,Szostak, Roman,Szostak, Michal
, p. 4703 - 4709 (2020/06/17)
The development of new amide precursors for selective, catalytic activation of carbon-nitrogen bonds in amides is a fundamental objective of this emerging reactivity manifold. We report the palladium-catalyzed Suzuki-Miyaura cross-coupling of N-acylcarbazoles and N-acylindoles with arylboronic acids by a highly selective N-C(O) cleavage. The key amide bond ground-state destabilization stems from Nlp to Ar conjugation and enables us for the first time to achieve reactivity similar to that for N-acylsulfonamide and N-acylcarbamate activation in simple anilides.
Direct Alkoxycarbonylation of Heteroarenes via Cu-Mediated Trichloromethylation and in Situ Alcoholysis
Jiang, Huanfeng,Jiang, Kai,Li, Yingwei,Luo, Wenkun,Yin, Biaolin
supporting information, (2020/03/04)
We report an efficient approach for direct alkoxycarbonylation of furans as well as other heteroarenes via a one-step copper-mediated reaction of three components (i.e., heteroarene, alcohol, and CHCl3). The copper additive was confirmed to simultaneously promote the reaction in three pathways: oxidant cracking, single electron transfer, and alcoholysis. By means of this protocol, various functionalized furancarboxylates and other heteroarenecarboxylates were facilely obtained in moderate to good yields.
Iron-Catalyzed Oxidative Decarbonylative α-Alkylation of Acyl-Substituted Furans with Aliphatic Aldehydes as the Alkylating Agents
Luo, Wenkun,Yang, Yongjie,Liu, Bo,Yin, Biaolin
, p. 9396 - 9404 (2020/08/14)
A protocol for FeCl2-catalyzed oxidative decarbonylative α-alkylation of acyl furans using alkyl aldehydes as the alkylating agents has been developed. This protocol affords α-alkyl-α-acylfurans in moderate to good yields in a practical and sustainable fa
Ionic liquid-mediated benzoyl transfer-coupling in the Suzuki and Sonogashira reactions and aryl transfer-coupling by decarbonylative Heck reaction, using N-Benzoyl-saccharin (NBSac) as reagent
Malunavar, Shruti S.,Sutar, Suraj M.,Prabhala, Pavankumar,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
, (2020/05/18)
The efficacy of N-benzoyl-saccharin (NBSac) as reagent for selective benzoyl transfer-coupling in the Suzuki reaction in BMIM-IL/[PAIM][NTf2] as solvent/base, and in the Sonogashira reaction employing guanidinium-IL (GIL) as solvent, are demonstrated. Decarbonylative aryl transfer-coupling occurs in the Heck reaction employing GIL as solvent. The reactions are catalyzed by Pd(OAc)2 or NiCl2(dppp), are performed under mild conditions in good yields, and have the potential for recycling/reuse of the IL solvent. Collectively, these methods provide facile access to diverse libraries of diarylketones, keto-ethynes and diaryl-ethenes.
