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Organocalcium compounds are highly reactive reagents whereas the alkaline-earth metal itself is a weak reductant. This discrepancy hampered a straightforward development of an organocalcium chemistry. The in situ generation of the highly reactive organocalcium reagent and immediate metalation of a H-acidic compound (iGMM) or addition onto a polar π-system (iGAM) offers not only a loophole to organocalcium reagents but opens the entry to a rich organic chemistry of this non-toxic and globally abundant alkaline-earth metal, being competitive to the organolithium chemistry. [ABSTRACT FROM AUTHOR]

Metalation of N‐mesityl‐P,P‐diphenylphosphinic amide with nBuLi in toluene yields tetranuclear lithium N‐mesityl‐P,P‐diphenylphosphinimidate ([Ph2P(OLi)=N−Mes]4, 1). Metalation of Ph2P(O)−N(H)Mes with a mixture of dibutylmagnesium and butyllithium in DME leads to formation of dinuclear [Ph2P{OLi(dme)}=N−Mes]2 (2). Excess of Ph2P(O)−N(H)Mes gives dinuclear [Li(O−PPh2=N−Mes){Ph2P(=O)−N(H)−Mes}]2 (3) with three‐coordinate alkali ions. The metathetical approach via reaction of 1 with anhydrous magnesium bromide in ethereal solution yields [{(thf)LiBr}2{(thf)Li(O−PPh2=NMes)(Et2O)Li(O−PPh2=NMes)}] (4). Heterobimetallic Li/Mg compounds are not accessible by these protocols. Reactions of 1 with DME, with excess of Ph2P(O)−N(H)Mes or with LiBr allows the straightforward conversion to compounds 2, 3 and 4. [ABSTRACT FROM AUTHOR]

Lithiation of the bis(pyrazolyl)methanes H2C(PzAd,Me)2 (1 a) and H2C(PzPh,Ph)2 (1 b) and subsequent addition of N,N'‐diisopropylcarbodiimide in THF yields [(thf)Li{(PzAd,Me)2HC−C(=NiPr)(NiPr)}] (2 a) and [(thf)Li{(PzPh,Ph)2HC−C(=NiPr)(NiPr)}] (2 b). For comparison reasons, the structure of [(thf)Li{(PztBu,tBu)2HC−C(=NCy)(NCy)}] (I) has been determined as well. Protolysis with aqueous ammonium chloride solution gives (PzAd,Me)2HC−C(=NiPr)(NHiPr) (3 a) and (PzPh,Ph)2HC−C(=NiPr)(NHiPr) (3 b). Zincation with diethylzinc leads to the formation of [EtZn{(PzAd,Me)2HC−C(=NiPr)(NiPr)}] (4 a) and [EtZn{(PzPh,Ph)2HC−C(=NiPr)(NiPr)}] (4 b). The metathetical approach allows preparation and isolation of [ClZn{(PzPh,Ph)2HC−C(=NiPr)(NiPr)}] (5). A comparison of the molecular structures of the lithium and zinc complexes allows to elucidate the influence of electronegativity on structural parameters because tetra‐coordinate Li and Zn ions have very similar radii. [ABSTRACT FROM AUTHOR]

Metalation of 2,4,6-triphenylphenylamine (H2N-C6H2-2,4,6-Ph3, 1a) and 4-methyl-2,6-bis(diphenylmethyl)aniline (2,6-bis(diphenylmethyl)-p-toluidine, H2N-C6H2-4-Me-2,6-(CHPh2)2, 2a) with dibutylmagnesium and Ae[N(SiMe3)2]2 with a stoichiometric 1 : 2 ratio in THF at room temperature yields the corresponding primary anilides [(thf)nAe{N(H)-C6H2-2,4,6-Ph3}2] (Ae/n = Mg/2 (1b), Ca/2 (1c), Sr/3 (1d), and Ba/3 (1e)) and [(thf)nAe{N(H)-C6H2-4-Me-2,6-(CHPh2)2}2] (Ae/n = Mg/2 (2b), Ca/3 (2c) and Sr/2 (2d)), respectively. The 1 : 1 reaction of Mg(n/sBu)2 and MgPh2 with 2a leads to the formation of heteroleptic [(thf)2Mg(R){N(H)-C6H2-4-Me-2,6-(CHPh2)2}] (R = n/sBu (2bBu), Ph (2bPh)). At 50 °C, the strontium complex 2d liberates one equivalent of 2avia intramolecular deprotonation of the triarylmethyl functionality yielding dinuclear [(thf)2Sr{N(H)-C6H2-4-Me-2-(CPh2)-6-(CHPh2)2}]2 (2d′). The barium compound is significantly more reactive and regardless of applied stoichiometry the isotypic barium congener [(thf)2Ba{N(H)-C6H2-4-Me-2-(CPh2)-6-(CHPh2)2}]2 (2e′) forms. The molecular structures of 1c, 2d, 2d′, and 2e′ are stabilized by metal-phenyl π-interactions. [ABSTRACT FROM AUTHOR]

Deprotonation of phenyl‐bis(3,5‐dimethylpyrazolyl)methane (HC(Ph)(PzMe2)2, 1 a) with [(thf)2Ca{N(SiMe3)2}2] in THF at −40 °C yields heteroleptic [(thf)2Ca{N(SiMe3)2}{C(Ph)(PzMe2)2}] (2 a) and finally homoleptic [(thf)Ca{C(Ph)(PzMe2)2}2] (2 b). However, these complexes degrade at room temperature to calcium bis(pyrazolate) and 2‐phenyl‐4,6‐dimethylpyrimidine (3 a). This degradation is accelerated when bulky phenyl‐bis(3‐adamantyl‐5‐methylpyrazolyl)methane (HC(Ph)(PzAd,Me)2, 1 b) is treated similarly and 2‐phenyl‐4‐adamantyl‐6‐methylpyrimidine (3 b) forms quickly. Sodiation of 1 a and 1 b with NaN(SiMe3)2 yields [{HC(Ph)(PzMe2)2}Na{C(Ph)(PzMe2)2}] (4 a) and [{HC(Ph)(PzAd,Me)2}Na{C(Ph)(PzAd,Me)2}] (4 b). The stronger metalation reagent benzylpotassium is able to quantitatively deprotonate 1 b leading to dinuclear [K{C(Ph)(PzAd,Me)2}]2 (4 c). The metathetical approach and the reaction of 4 c with metal(II) halides of Mg, Ca and Zn again leads to degradation and formation of pyrimidine 3 b. This decomposition of the ligand can be circumvented when the sidearm contains the anionic charge. Thus, 2‐hydroxyphenyl‐bis(3‐adamantyl‐5‐methylpyrazol‐1‐yl)methane (1 c) reacts with [(thf)2Ca{N(SiMe3)2}2] in THF to the homoleptic complex [(thf)4Ca{O−C6H4−CH(PzAd,Me)2}] (2 c). In this complex, THF and pyrazolyl bases compete in the coordination sphere and preparation of a heteroleptic complex fails. To avoid the binding competition between THF and pyrazolyl bases and to stabilize heteroleptic calcium complexes, the reaction has been repeated in toluene yielding [Ca{N(SiMe3)2}{O−C6H4−CH(PzAd,Me)2}]2 (2 d). [ABSTRACT FROM AUTHOR]

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