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Although sufficient tolerance against attack by superoxide radicals (O 2 - ) has been mainly recognized as an important property for Li-O 2 battery (LOB) electrolytes, recent evidence has revealed that other critical factors also govern the cyclability, prompting a reconsideration of the basic design guidelines of LOB electrolytes. Here, we found that LOBs equipped with a N,N-dimethylacetamide (DMA)-based electrolyte exhibited better cyclability compared with other standard LOB electrolytes. This superior cyclability is attributable to the capabilities of quenching 1 O 2 and forming highly decomposable Li 2 O 2 . The 1 O 2 quenching capability is equivalent to that of a tetraglyme-based electrolyte containing a several millimolar concentration of a typical chemical quencher. Based on these overlooked factors, the DMA-based electrolyte led to superior cyclability despite its lower O 2 - tolerance. Thus, the present work provides a novel design guideline for the development of LOB electrolytes., (© 2022 Wiley-VCH GmbH.)

The carbon-carbon (C-C) bond activation of [n]cycloparaphenylenes ([n]CPPs) by a transition-metal complex is herein reported. The Pt 0 complex Pt(PPh 3 ) 4 regioselectively cleaves two C-C σ bonds of [5] CPP and [6]CPP to give cyclic dinuclear platinum complexes in high yields. Theoretical calculations reveal that the relief of ring strain drives the reaction. The cyclic complex was further transformed into a cyclic diketone by using a CO insertion reaction., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, a copper-catalyzed C-F bond defluorosilylation reaction of tetrafluoroethylene and other polyfluoroalkenes is described. Mechanistic studies, based on a series of stoichiometric reactions with copper complexes, revealed that the key steps of this defluorosilylation reaction are 1) the 1,2-addition of a silylcopper intermediate to the polyfluoroalkene and 2) a subsequent selective β-fluorine elimination, which generates a Cu-F species. The β-fluorine elimination is facilitated by Lewis acidic F-Bpin, which is generated in situ during the defluorosilylation., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A transition-metal-free catalytic hydrodefluorination (HDF) reaction of polyfluoroarenes is described. The reaction involves direct hydride transfer from a hydrosilicate as the key intermediate, which is generated from a hydrosilane and a fluoride salt. The eliminated fluoride regenerates the hydrosilicate to complete the catalytic cycle. Dispersion-corrected DFT calculations indicated that the HDF reaction proceeds through a concerted nucleophilic aromatic substitution (CS N Ar) process., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The copper(I)-mediated generation of -OCF 2 CF 2 - moieties by the oxycupration of tetrafluoroethylene (TFE) using either copper aryloxides or alkoxides is disclosed. The key intermediates, 2-aryloxy-1,1,2,2-tetrafluoroethyl and 2-alkoxy-1,1,2,2-tetrafluoroethyl copper complexes, were obtained from the reaction of the corresponding aryloxy and alkoxy copper complexes with TFE, and their structures in solution and in the solid state were unambiguously determined by multinuclear NMR spectroscopy and X-ray diffraction analysis. These copper complexes subsequently reacted with aryl iodides (ArI) to afford ROCF 2 CF 2 Ar (R=aryl or alkyl) in high yields., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The nickel(0)-catalyzed carbonylative cycloaddition of 1,5- and 1,6-ene-imines with carbon monoxide (CO) is reported. Key to this reaction is the efficient regeneration of the catalytically active nickel(0) species from nickel carbonyl complexes such as [Ni(CO) 3 L]. A variety of tri- and tetracyclic γ-lactams were thus prepared in excellent yields with 100 % atom efficiency. Preliminary results on asymmetric derivatives promise potential in the synthesis of enantioenriched polycyclic γ-lactams., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In the presence of Ni 0 /PCy 3 , styrene was found to participate in oxidative cyclization with tetrafluoroethylene, thus leading to the corresponding nickelacycle with a unique η 3 -π-benzyl structure. In addition, the flexibility of the coordination mode in the η 3 -benzyl moiety allowed the partially fluorinated nickelacycle to undergo unprecedented amine-induced α-fluorine elimination, thus leading to the construction of a fluorinated cyclobutyl skeleton., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Direct synthesis of carboxylic-phosphinic mixed anhydrides has been achieved by treating carbon dioxide with N-phosphine oxide-substituted imidazolylidenes (PoxIms) that contain both nucleophilic carbene and electrophilic phosphorus moieties. This novel mixed anhydride was efficiently derivatized into an ester, an amide, and an unsymmetrical ketone via transformation into its corresponding imidazolium salt followed by a dual substitution reaction. The presented work used well-designed multifunctional carbene reagents to establish a novel utility for carbon dioxide in organic synthesis., (© 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

A copper-catalyzed reaction of easily accessible α,α,α-trifluoromethylketones with various aldehydes affords difluoro-methylene compounds in the presence of diboron and NaOtBu. The key process of the reaction is the formation of a copper difluoroenolate by 1,2-addition of a borylcopper intermediate to α,α,α-trifluoromethylketones and subsequent β-fluoride elimination. Mechanistic studies including the isolation and characterization of a possible anionic copper alkoxide intermediate are also described., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

N-Phosphine oxide substituted imidazolylidenes (PoxIms) have been synthesized and fully characterized. These species can undergo significant changes to the spatial environment surrounding their carbene center through rotation of the phosphine oxide moiety. Either classical Lewis adducts (CLAs) or frustrated Lewis pairs (FLPs) are thus formed with B(C6 F5 )3 depending on the orientation of the phosphine oxide group. A strategy to reactivate FLPs from CLAs by exploiting molecular motions that are responsive to external stimuli has therefore been developed. The reactivation conditions were successfully controlled by tuning the strain in the PoxIm-B(C6 F5 )3 complexes so that reactivation only occurred above ambient temperature., (© 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.)

A chemoselective C(sp(2) )F or C(sp(3) )F bond activation of hexafluoropropylene (HFP) was achieved by adopting the proper combination of a Lewis acid co-additive with a ligand which coordinates Pd(0) . The treatment of [(η(2) -HFP)Pd(PCy3 )2 ] with B(C6 F5 )3 allowed a chemoselective C(sp(3) )F bond cleavage of HFP to give a unique cationic perfluoroallypalladium complex. In this complex, the coordination mode of the perfluoroallyl ligand was considered to be of the unique η(2) -fashion., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)