Deprotonation of alkyl and vinyl carbon-hydrogen bonds for synthetic purposes is often hindered not merely by the need an exceptionally strong base, but inherent instability resultant anion. Metalation cyclic ethers adjacent to oxygen, example, has invariably initiated a ring-opening decomposition pathway. Here, we show that use bimetallic base can overcome such through cooperative combination zinc-carbon sodium-oxygen bonding. Both tetrahydrofuran tetrahydropyran reacted cleanly over days...

Die molekularen Mechanismen, die verbesserten Magnesierungsreaktionen zugrunde liegen, werden durch Aufklärung der Struktur einer 2,2,6,6-Tetramethylpiperidid(TMP)-Hauser-Base und ihrer "Turbo-Variante" erkennbar (siehe Bild; Mg grün, Li pink, C violett, O rot, N blau, Cl gelb).

The synthesis, structure and reactivity of donor-free sodium potassium magnesiates are assessed culminating in the unique 1,4-dimetallation naphthalene.

Mixed N-heterocyclic carbene (NHC) / pyridyl iron(II) complexes have attracted a great deal of attention recently because their potential as photocatalysts and light sensitizers made from Earth-abundant elements. The most decisive challenge for successful implementation is the lifetime lowest triplet metal-to-ligand charge transfer state (

Magic Metalation: Inert towards conventional organomanganese reagents, ferrocene can now be directly manganated by using a specially designed mixed lithium/manganese(II) dialkyl/amido reagent. The picture shows the structure of dimanganese compound with three 1,1′-ferrocenediyl fragments.

Abstract Check M(etal)ate: The chessboard and the figures represent a special reaction in which different low‐polarity metals can metalate arenes directly when they are brought into right position. In combination of queen (sodium) knight (chromium or iron), it is possible for (usually weaker piece) to make direct deadly hit on king (benzene) this game elemental chess. magnified image

Engagement ring: α-Metalated by a lithium bisamido-bisalkylaluminate base, the sensitive cycloanionic ring of THF or THTP remains intact engaging with both metal centers base residue (see structure; X=O, S). Metalation has served well for over 80 years as vehicle transforming inert CH bonds in organic compounds to reactive Cmetal bonds.1 Progress metalation was accelerated greatly development DoM (directed ortho-metalation),2 pioneered Snieckus, Beak, and others, special type lithiation...

The study of co-complexation reactions between NaCH(2)SiMe(3) and Mg(CH(2)SiMe(3))(2) has allowed the isolation structural elucidation first solvent-free alkali-metal alkylmagnesiate [{NaMg(CH(2)SiMe(3))(3)}(∞)] (1) as well related sodium alkyl [{(NaCH(2)SiMe(3))(4)}(∞)] (3).

Abstract [(Trimethylsilyl)methyl]sodium [NaCH 2 SiMe 3 ] ( 1 ) was prepared by a metathesis reaction of [(trimethylsilyl)methyl]lithium [LiCH with sodium tert ‐butoxide in n ‐hexane. Polydentate donors such as N , N′ ‐tetramethylethylenediamine (TMEDA) and N″ ‐pentamethyldiethylenetriamine (PMDETA) form ‐hexane‐soluble complexes the potassium congener [KCH ). The crystal structures polymers [(TMEDA)NaCH 1a [(PMDETA)KCH 2a were determined infinite helical chains exhibiting or screw‐axis...

Abstract The sterically encumbered polymeric dialkyl complexes [M(CH 2 SiMe 3 ) ] ∞ [M = Mg, Mn II were deaggregated by the potent two‐electron σ‐donor, 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr), to yield first examples of monomeric three‐coordinate · donor Mg ( 1 ); )]. Similarly, species M[CH(SiMe IPr Mn, 4 )] obtained from bulkier disilyl‐substituted alkyl [CH(SiMe congeners ether displacement IPr. Complexes – , which represent rare N‐heterocyclic‐carbene‐stabilized...

This paper presents the synthesis and characterization of new homoleptic lithium magnesiate reagents incorporating silyl-substituted alkyl ligand CH2SiMe3 in presence a variety Lewis base donors, namely tetrahydrofuran (THF), 1,4-dioxane, N,N,N′,N′-tetramethylethylenediamine (TMEDA), N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA). The constitution these bimetallic compounds has been assessed both solid state solution using combination X-ray crystallographic studies multinuclear NMR...

Abstract Mixtures of alkyllithium and heavier alkali‐metal alkoxides are often used to form alkyl compounds alkali metals, but these mixtures also known for their high reactivity in deprotonative metalation reactions. These organometallic called LiC–KOR superbases, despite many efforts constitution remains unknown. Herein we present mixed alkyl/alkoxy produced by reaction neopentyllithium with potassium tert ‐butoxide. The key success was the good solubility temperature‐stability neopentyl...

Meta–meta metalation: Remarkably, toluene can be directly dimanganated or dimagnesiated at the 3,5-positions using bimetallic bases with active Me3SiCH2 ligands (see scheme, blue). In contrast, n-butyl lead to 2,5-metalation (red). tmp=2,2,6,6-tetramethylpiperidide. Organolithium reagents have long enjoyed iconic status amongst synthetic chemists, in part because of their unrivaled ability affect directed metalation (lithiation, lithium–hydrogen exchange) reactions on arenes, heteroarenes,...

Inside out approach: Twofold deprotonation of benzene by a sodium monoalkyl bisamido manganate(II) reagent derived from BuNa, 2,2,6,6-tetramethylpiperidine, and Mn(CH2SiMe3)2 has produced the first inverse-crown complex in which transition-metal atoms are incorporated host (see X-ray structure, blue N, green Na, purple Mn). Variable-temperature magnetization measurements show that is antiferromagnetic.

Abstract Extending the recently introduced concept of “alkali‐metal‐mediated manganation” to functionalised arenes, heteroleptic sodium manganate reagent [(tmeda)Na(tmp)(R)Mn(tmp)] ( 1 ; TMEDA= N , ′, ′‐tetramethylethylenediamine, TMP=2,2,6,6‐tetramethylpiperidide, R=CH 2 SiMe 3 ) has been treated with anisole or ‐diisopropylbenzamide in a 1:1 stoichiometry hexane. These reactions afforded crystalline products [(tmeda)Na(tmp)( o ‐C 6 H 4 OMe)Mn(tmp)] and [(tmeda)Na(tmp){ ‐{C(O)N( i Pr) C...

The new synergic base [PMDETA·K(TMP)(Et)Zn(Et)] selectively zincates 4-(dimethylamino)pyridine at the 2-position and 4-methoxypyridine 3-position, to afford bimetallic potassium pyridylzinc complexes each displaying a novel, but remarkably different, structure.

Three Lewis base variations of the synthetically useful aluminate [L·Li(TMP)(iBu)Al(iBu)2], where L is TMPH, Et3N or PhC(O)NiPr2, are reported, together with reaction benzamide complex 1,4-dioxane, which surprisingly leads to fragmentation cyclic ether and capture its alkoxy vinyl residue within a novel dilithium dialuminium hexaalkyl aggregate.

Extending to transition metals, the class of compounds known as inverse crown ethers, two mixed alkali metal-manganese(II) amide ring with oxo cores have been synthesised and crystallographically characterised, together an oxo-free alkyl-amido precursor.

With the aim of introducing diisopropylamide [NiPr(2)](-) ligand to alkali-metal-mediated manganation (AMMMn) chemistry, temperature-dependent reactions a 1:1:3 mixture butylsodium, bis(trimethylsilylmethyl)manganese(II), and diisopropylamine with ferrocene in hexane/toluene have been investigated. Performed at reflux temperature, reaction affords surprising, ferrocene-free, hydrido product [Na(2)Mn(2) (mu-H)(2){N(iPr)(2)}(4)]2 toluene (1), first Mn inverse crown complex. Repeating...

A series of four ferrocenyl ester compounds, 1-methoxycarbonyl- ( 1 ), 1,1’-bis(methoxycarbonyl)- 2 1,1’,3-tris(methoxycarbonyl)- 3 ) and 1,1’,3,3’-tetrakis(methoxycarbonyl)ferrocene 4 has been studied with respect to their potential use as redox mediators. The impact the number position groups present in – on electrochemical E 1/2 is correlated sum Hammett constants. / + couples are chemically stable under conditions electrolysis demonstrated by IR UV–vis spectroelectrochemical methods....

The first neutral base-free silylcopper compound 1 (structure depicted) was obtained by ligand exchange of bis(hypersilyl)lead and CuAr* (Ar*C6H3Mes2-2,6). In the solid state, forms trimers (1)3 with short Cu⋅⋅⋅Cu contacts relatively long Cu−Si bonds. Surprisingly, analogous reaction bis(hypersilyl)tin does not yield 1. Instead, a novel complex heteroleptic stannanediyl is formed, which contains covalent Cu−Sn bond.

Using structurally well-defined dipotassium-tetra(alkyl)magnesiates, a new straightforward methodology to promote regioselective Mg-H exchange reactions of wide range aromatic and heteroaromatic substrates is disclosed. Contacted ion pair intermediates are likely be involved, with K being the key facilitate magnesiation processes.