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The regioselective introduction of an alkenyl moiety on indoles can be achieved by exploiting the intrinsic reactivity of this heterocycle toward C‐3 substitution. Conversely, the appropriate functionalization of the indole nitrogen atom allows to direct the alkenylation at C‐2. Metal‐catalyzed C−H activation and reaction with alkenes, hydroindolation of alkynes and condensation reactions with carbonyl derivatives are the main procedures adopted for the alkenylation of indoles. For more information see the Review article by M. Petrini on page 16115 ff. [ABSTRACT FROM AUTHOR]

Synthetic Methods Asymmetric catalytic processes have been indispensable for the synthesis of enantioselective materials to meet demands from various fields. Michael addition has been used extensively for the construction of C−C bonds under mild conditions. Previously reported applications of metal‐catalyzed asymmetric Michael additions in natural product synthesis are presented here and discussed in depth, see Minireview by J. Xu et al. on page 4023 ff. [ABSTRACT FROM AUTHOR]

The front cover image, provided by Kylie Agnew ‐ Francis and Craig Williams, illustrates diverse examples of catalytic systems that contain the sterically bulky adamantane moiety. This ‘big guy’ molecule has become well regarded in the literature for its powerful electron ‐ donating properties in addition to its size, and has thus marked its place in the organic chemist’s toolbox as an excellent (and often superior) addition to catalyst and ligand design. Details can be found in the review on pages 675 – 700 (K. A. Agnew ‐ Francis, C. M. Williams, Adv. Synth. Catal.­ 2016, 358, 675 – 700; DOI:10.1002/adsc.201500949). [ABSTRACT FROM AUTHOR]

The Ni II complex 1 containing pyridyl- and hydroxy-functionalized N-heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base-free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen-bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α-hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds 2 and 4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds 1 and 3) show substantial activity. The linkage isomer 1' where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pK a measurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand-promoted nucleophilic water addition to a metal-bound nitrile group. This work reports a Ni-based catalyst that exhibits functional hemilability for hydration chemistry., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Polynucleotide ligases comprise a ubiquitous superfamily of nucleic acid repair enzymes that join 3'-OH and 5'-PO 4 DNA or RNA ends. Ligases react with ATP or NAD + and a divalent cation cofactor to form a covalent enzyme-(lysine-Nζ)-adenylate intermediate. Here, we report crystal structures of the founding members of the ATP-dependent RNA ligase family (T4 RNA ligase 1; Rnl1) and the NAD + -dependent DNA ligase family ( Escherichia coli LigA), captured as their respective Michaelis complexes, which illuminate distinctive catalytic mechanisms of the lysine adenylylation reaction. The 2.2-Å Rnl1•ATP•(Mg 2+ ) 2 structure highlights a two-metal mechanism, whereby: a ligase-bound "catalytic" Mg 2+ (H 2 O) 5 coordination complex lowers the p K a of the lysine nucleophile and stabilizes the transition state of the ATP α phosphate; a second octahedral Mg 2+ coordination complex bridges the β and γ phosphates; and protein elements unique to Rnl1 engage the γ phosphate and associated metal complex and orient the pyrophosphate leaving group for in-line catalysis. By contrast, the 1.55-Å LigA•NAD + •Mg 2+ structure reveals a one-metal mechanism in which a ligase-bound Mg 2+ (H 2 O) 5 complex lowers the lysine p K a and engages the NAD + α phosphate, but the β phosphate and the nicotinamide nucleoside of the nicotinamide mononucleotide (NMN) leaving group are oriented solely via atomic interactions with protein elements that are unique to the LigA clade. The two-metal versus one-metal dichotomy demarcates a branchpoint in ligase evolution and favors LigA as an antibacterial drug target.

The front cover picture provided by Wei ‐ Cheng Yuan and co ‐ workers illustrates the recent advances in catalytic asymmetric cascade reactions with α ‐ isothiocyanato compounds as new type of versatile reagents. In recent years, numerous catalytic asymmetric reactions, including asymmetric cascade aldol/cyclization, Mannich/cyclization, Michael/cyclization, [3+2] cyclization with allenic esters, [3+2] cyclization with 2 ‐ butynedioic acid diesters, [3+2] cyclization with azodicarboxylates, as well as self ‐ cyclization/addition with aziridines, were successfully developed by using α ‐ isothiocyanato compounds. Details can be found in the review on pages 3007 – 3031 (W. ‐ Y. Han, J. ‐ Q. Zhao, J. Zuo, X. ‐ Y. Xu, X. ‐ M. Zhang, W. ‐ C. Yuan, Adv. Synth. Catal.­ 2015, 357, 3007 – 3031; DOI: 10.1002/adsc.201500264). [ABSTRACT FROM AUTHOR]

Thioxanthones - being readily available in one step from thiosalicylic acid and arenes - were used in ruthenium-catalyzed C-H-activation reaction to produce 1-mono- or 1,8-disubstituted thioxanthones in good to excellent yields. Scope and limitation of this reaction are presented.

Ruthenium-catalyzed reductive couplings of paraformaldehyde with dienes, alkynes, and allenes provide access to products of hydrohydroxymethylation that cannot be formed selectively under the conditions of hydroformylation. In certain cases, the regioselectivity of the CC coupling can be inverted by using nickel catalysts. With iridium catalysts, methanol engages in redox-neutral regioselective hydrohydroxymethylations., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)