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Aminosilylene, comprising reactive NH− and Si(II) sites next to each other, is an intriguing class of compounds due to its ability to show diverse reactivity. However, stabilizing the reactive NH− group next to the free Si(II) atom is challenging and has not yet been achieved. Herein, we report the first examples of base stabilized free aminosilylenes Ar*NHSi(PhC(NtBu)2) (1 a) and Mes*NHSi(PhC(NtBu)2) (1 b) (Ar*=2,6‐dibenzhydryl‐4‐methylphenyl and Mes*=2,4,6‐tri‐tert‐butylphenyl), tolerating a NH− group next to the naked Si(II) atom. Remarkably, 1 a and 1 b exhibited interesting differences in their reactivity upon heating. With 1 a, an intramolecular C(sp3)−H activation of one of the benzhydryl methine hydrogen atoms to the Si(II) atom produced the five‐membered cyclic silazane 2. However, with 1 b, a rare 1,2‐hydrogen shift to the Si(II) atom afforded a silanimine 3, with a hydride ligand attached to an unsaturated silicon atom. Further, the coordination capabilities of 1 a were also tested with Ru(II) and Fe(0) precursors. Treatments of 1 a with [Ru(η6‐p‐cymene)Cl2]2 led to the isolation of a η6‐arene tethered complex [RuCl2{Ar*NHSi(PhC(tBuN)2)‐κ1‐Si‐η6‐arene}] (4), whereas with the Fe(CO)5 precursor a Fe(0) complex [Fe(CO)4{Ar*NHSi(PhC(tBuN)2)‐κ1‐Si}] (5) was obtained. Density functional theory (DFT) calculations were conducted to shed light on the structural, bonding, and energetic aspects in 1–5. [ABSTRACT FROM AUTHOR]

• Two pincer-type Ru catalysts with proton-responsive group exhibited excellent performance for β-alkylation of alcohols. • The 2a catalyst exhibited excellent performance for β-alkylation of secondary alcohols with primary alcohols. • The role of protic NHC group on performance of β-alkylation have been investigated. This study investigated the catalytic activities of two pincer Ru complexes with bifunctional metal-ligand cooperativity, namely (HO-C 5 H 3 N-CH 2 -C 5 H 3 N-NHC)Ru(PPh 3) 2 Cl (1a) and (C 5 H 4 N-CH 2 -C 5 H 3 N-NHC)Ru(PPh 3) 2 Cl (2a), for C C bond formation through the borrowing hydrogen process. Surprisingly, complex 2a , which lacks the 2-hydroxypyridyl fragment, exhibited comparable activity to complex 1a with the same catalyst loading in the coupling of a broad range of primary and secondary alcohols. The efficiency of this straightforward system was further demonstrated in the challenging reaction of β-alkylation of 1-phenylethanol with benzyl alcohol, with a minimal catalyst loading of 0.0001 mol.%. The highest TOF observed for the cross-coupling of alcohols was 13,333 h−1. Additionally, complex 2a was found to be effective in catalysing β-alkylation of aliphatic secondary alcohols with primary alcohols and double C-alkylation of cyclopentanol. This finding holds promise for the development of more effective bifunctional catalysts for β-alkylation reactions of primary and secondary alcohols. [Display omitted] [ABSTRACT FROM AUTHOR]

Bis-protic N-heterocyclic carbene complexes of platinum and palladium (4) yield dimeric structures 6 when treated with sodium tert-butoxide in CH2Cl2. The use of a more polar solvent (THF) and a strong base (LiN(iPr)2) gave the lithium chloride adducts monobasic complex 7 or analogous dibasic complex 8.

The adenine derivative 8-bromo-9-ethyl-1, N 6-ethenoadenine 3 has been synthesized and oxidatively added to [M0(PPh 3) 4 ] (M = Pd, Pt). Depending on the procedure for the protonation as well as the metal, either the mononuclear complexes trans -[ 4 ]BF 4 and trans -[ 5 ]BF 4 or the dinuclear complex [ 6 ](BF 4) 2 were obtained. [Display omitted] • First NHC complex of 1, N 6-ethenoadenine. • First dinuclear platinum NHC complex of a purine-derived ligand. • Protic NHC complexes of a purine-derived ligand. The 8-bromoadenine derivative 8-bromo-9-ethyl-1, N 6-ethenoadenine 3 was prepared from adenine in three steps. Treatment of 8-bromo-9-ethyl-1, N 6-ethenoadenine 3 with the zero-valent metal precursors [M0(PPh 3) 4 ] (M = Pd, Pt) in the presence of NH 4 BF 4 as proton source gave exclusively the compounds trans -[ 4 ]BF 4 and trans -[ 5 ]BF 4. The obtained complexes bear a modified C8-bound adenine derivative with a protonated endocyclic nitrogen atom N7. A stepwise reaction sequence consisting of an initial oxidative addition of the C8–Br bond of 3 to [Pt0(PPh 3) 4 ] followed by treatment with HBF 4 ·Et 2 O as proton source led to the dinuclear complex [ 6 ]2+ after a reaction time of several days. This complex features two adenine-derived NHC ligands coordinating to two PtII ions in a µ - κ C8: κ N7 bridging fashion. Protonation of the NHC ligands occurred at the nitrogen atom N6 instead of N7 of the purine scaffold. The molecular structures of the three complexes were determined by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

Bis-protic N-heterocyclic carbene complexes of platinum and palladium (4) yield dimeric structures 6 when treated with sodium tert-butoxide in CH2Cl2. The use of a more polar solvent (THF) and a strong base (LiN(iPr)2) gave the lithium chloride adducts monobasic complex 7 or analogous dibasic complex 8.