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The inside cover picture shows recent advances and challenges in the catalytic enantioselective synthesis of fluorinated α‐ and β‐amino acids. This topic provides important guidance and some inspiration for the researchers engaged in organic fluorine and medicinal chemistry. Details can be found in the review by Jin‐Sheng Yu and co‐workers. (X.‐X. Zhang, Y. Gao, X.‐S. Hu, C.‐B. Ji, Y.‐L. Liu, J.‐S. Yu, Adv. Synth. Catal. 2020, 362, XXXX–YYYY; DOI: 10.1002/adsc.202000966).
Aryl hydrazines, propiolic acid esters and enals serve as a viable substrate combination for an organocatalytic enantioselective Hantzsch type reaction. The method converts readily available starting materials into important chiral heterocycles with good to excellent yields and enantioselectivities, and has addressed the longstanding scope limitation of the classic Hantzsch reaction in the asymmetric synthesis of 2,6‐unsubstituted hydropyridines. The synthetic utility has been demonstrated by the concise enantioselective synthesis of paroxetine.
The switchable catalytic approach for the regioselective intramolecular hydroarylation of ynone has been developed. When ZnI2 was used as catalyst, the umpolung α‐arylation of ynone was realized via an addition‐elimination process of iodine ion to generate the PQM intermediate, which could be trapped by styrene to form benzo[f,h]chromenes through hetero‐Diels‐Alder reaction. While IPrAuCl/AgSbF6 was applied, however, the β‐arylation of ynone took place to afford benzocycloheptene‐5‐ones in moderate to excellent yields.
Herein we report the first Ni(II)‐catalysed transfer hydrogenation of quinolines using ammonia borane (AB) as hydrogen (H2) source. An in situ generated Ni(II)‐bis(pyrazolyl)pyridine pre‐catalyst could hydrogenate quinoline and its derivatives in excellent yields of up to 90% at 25 °C in 30 minutes. Spectroscopic studies revealed that a Ni(II)‐hydride is responsible for the transfer hydrogenation of quinoline to 1,2,3,4‐tetrahydroquinoline via a 1,4‐dihydroquinoline intermediate.
Indole‐containing polycyclic hetero aromatic compounds are synthesized by multistep process, which have wide application in biological activities and organic semi‐conductor materials. Here in we report the one‐pot method for the synthesis of polysubstituted indolo[2,1‐a]isoquinolines by Ru(II) catalyzed double aryl/hetero aryl C(sp2)‐H activation through in‐situ installed carbamide of phenyl isocyanate and diaryl substituted alkynes/dihetero aryl substituted alkynes in the presence of Cu(OAc)2.H2O as an oxidant and CsOAc as an additive at 120 °C for 3 h in good to excellent yields.
A simple and efficient visible‐light‐initiated cascade reaction of 2‐isothiocyanatonaphthalenes and amines with ambient dioxygen as the sole oxidant under additive‐, external photocatalyst‐free and ambient conditions was developed. 38 Examples of N‐substituted naphtho[2,1‐d]thiazol‐2‐amines were regioselectively constructed in good to excellent yields.
Synthesis of pharmaceutically active heterocycles is always appealing as the majority of the widely used drugs contain heterocyclic moieties as their core structure. So, the straightforward construction of heterocycles from readily available/accessible reagents is one of the prime targets of the synthetic chemists. In this context, C‐H functionalization has emerged as an effective tool for the designing and synthesis of various heterocyclic moieties as it offers a straight‐forward and step‐economic pathway. On the other hand, the readily available/accessible conjugated carbonyls are well‐known reagents for the construction of carbocycles and heterocycles over the years. However, the employment of C‐H functionalization of the two C‐H bond of.
A cheap and efficient C(sp3)–H phosphorylation has been achieved via the iron‐catalyzed cross‐coupling reactions between 1,3‐dicarbonyl compounds and P(O)–H compounds involving C–C bond cleavages with air as the oxidant. This transformation provides a straightforward way to construct C(sp3)–P bonds, leading to the formation of β‐ketophosphine oxides in up to 93% yield with good functional group tolerance.
Phenothiazine is an important structural motif in pharmaceuticals and advanced functional organic materials. However, the C‐H functionalization reaction of N‐protected phenothiazine is rather unexplored and often shadowed by its chemical reactivity on the heteroatomic centers, which limits the diversity of its potential applications. This report demonstrates a straightforward approach towards the site‐selective C‐H functionalization of phenothiazine at the para‐position of N atom via gold‐catalyzed carbene transfer reactions (37 examples, up to 83% yield). The mechanism behind the regionselectivity of the C‐H functionalization reaction was also elucidated by a combination of computational and experimental studies.
N‐(Pyrid‐2‐yl)‐substituted azolium and pyridinium salts, precursors for hybrid NHC‐containing ligands, were obtained with excellent regioselectivity, employing a deoxygenative CH‐functionalization of pyridine‐N‐oxides with substituted imidazoles, thiazoles, and pyridine.
The front cover picture illustrates the diverse chemical building blocks and synthetic methods, including transition metal‐catalysed methodologies, that have been developed over the past decades to generate (E,Z)‐diene moieties. Many of the methodical developments were applied in total synthetic approaches of complex natural products containing one or more (E,Z)‐diene moieties. The review provides a full account of stereoselective strategies to build up E,Z‐configured 1,3‐dienes. Details can be found in the review by Renata Marcia de Figueiredo and collaborators. (P. Hubert, E. Seibel, C. Beemelmanns, J.‐M. Campagne, R. M. de Figueiredo, Adv. Synth. Catal. 2020, 362, XXXX–YYYY; DOI: 10.1002/adsc.202000730).
The importance of fluorinated organic molecules in drugs and pharmaceuticals led to the development of several synthetic methods for introducing fluorine into bioactive molecules and trifluoromethylation is one of the key approaches for the same. Electrochemical organic synthesis has emerged as one of the most sustainable, green synthetic strategies in recent years and new developments in electroorganic synthesis also focus on electrochemical trifluoromethylation of organic compounds. A considerable number of reports have appeared in recent literature and this review surveys all the recent developments in electrochemical trifluoromethylation reactions. This highly sustainable protocol for trifluoromethylation will emerge further soon and pa.
While remarkable progress has recently been made for the direct C‐H‐functionalization of azines, its application is still limited by a lack of accessible functional groups (primarily carbon‐based) and poor regioselectivity. In contrast, C2‐functionalized pyridines and quinolines can be easily synthesized by treating readily available N‐oxides with various reagents under appropriate activation conditions. This review seeks to comprehensively document the available synthetic methods for introducing functional groups at the C2 position of pyridines and quinolines. In this work, we highlight recent developments in the C2‐functionalization of pyridine and quinoline N‐oxides and address both the mechanisms and regioselectivity of the reactions. W.
Indole derivatives are important heterocycles in organic synthesis for serving as privileged building blocks for functional material and as key components in a lot of bioactive compounds. Propargylic alcohols, bearing alkynyl and hydroxyl functional groups, have emerged as promising feedstock materials for the construction of carbo‐ and heterocycles. Especially, in the last decade, the Lewis or Brønsted acid catalysed tandem annulations of propargylic alcohols to build structurally diverse indole derivatives have been well‐investigated. In this review, we summarize two main synthetic strategies toward indole derivatives via the cascade reactions of propargylic alcohols: indole‐ring formation involved tandem reactions and the direct function.
A synthetic strategy for the synthesis of substituted thiophenes is described by the one‐pot reaction of indoles with ketene dithioacetals under mild reaction conditions. Promoted by triflic acid (TfOH), the reaction of indoles with the easily available α‐acetyl ketene dithioacetals resulted in the formation of vinylketene dithioacetals via condensation instead of the well known nucleophilic addition‐alkylthio elimination process. In the presence of CuBr2, vinylketene dithioacetals can cyclize into the corresponding substituted thiophenes. This transformation may benefit from the acidic reaction conditions and the steric effects of the 2‐substituted indoles.
Molecules with di‐ or trichloromethyl group are widely existed in natural products and man‐made structures that represent special activities in pharmaceuticals and agrochemicals. Besides, polychloromethyl‐containing compounds are also high valuable intermediates in organic synthesis and also can be used as functional materials. Therefore, significant efforts have been made toward the incorporation of polychloromethyl groups into certain structures. In this field, a variety of polychloromethyl reagents, such as CH2Cl2, HCCl3, CCl4, TMSCCl3, TMSCCl2H, etc. have been utilized as the di‐ or trichloromethyl sources toward polychloromethylated structures through radical, nucleophilic, and other reaction patterns. In this review, we summarized and.

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