Reversible Addition of the Si–H Bond of Phenylsilane to the ScN Bond of a Scandium Terminal Imido Complex

The facile and reversible addition of the Si–H bond of phenylsilane to the ScN bond of the scandium terminal imido complex [LScNDIPP­(DMAP)] (<b>1</b>; L  [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMe)]⁻, DIPP = 2,6-^<i>i</i>Pr₂C₆H₃) is reported. The reaction gives the scandium anilido hydride [LSc­(H)­(N­(DIPP)­(SiH₂Ph))] (<b>2</b>), and a labeling experiment shows a rapid σ-bond metathesis between Sc–H of the formed scandium anilido hydride and Si–H of phenylsilane during the reaction. <b>2</b> was trapped by an insertion reaction with diphenylcarbodiimide, giving the stable scandium anilido amidinate [LSc­(N­(DIPP)­(SiH₂Ph))­(κ²(<i>N</i>,<i>N</i>′)-PhNCHNPh)] (<b>3</b>). Furthermore, the scandium terminal imido complex can efficiently catalyze the hydrosilylation of <i>N</i>-benzylidenepropan-1-amine. The reaction was completed within 2 h at 50 °C with 5 mol % of catalyst loading and highly selectively produced the monoaminosilane

Synthesis of Hemilabile Cyclic (Alkyl)(amino)carbenes (CAACs) and Applications in Organometallic Chemistry

A versatile methodology, involving readily available starting materials, allows for the synthesis of stable hemilabile bidentate cyclic (alkyl)­(amino)­carbenes (CAACs) featuring alkene, ether, amine, imine, and phosphine functionalities. The stability of the free carbenes has been exploited for the synthesis of copper­(I) and gold­(I) complexes. It is shown that the pendant imine moiety stabilizes the gold­(III) oxidation state and enables the C–C bond oxidative addition of biphenylene to the corresponding cationic gold­(I) complex. The latter and the corresponding copper­(I) complex show high catalytic activity for the hydroarylation of α-methylstyrene with <i>N</i>,<i>N</i>-dimethylaniline, and the copper­(I) complex promotes the <i>anti</i>-Markovnikov hydrohydrazination of phenyl acetylene with high selectivity

Synthesis of Hemilabile Cyclic (Alkyl)(amino)carbenes (CAACs) and Applications in Organometallic Chemistry

A versatile methodology, involving readily available starting materials, allows for the synthesis of stable hemilabile bidentate cyclic (alkyl)­(amino)­carbenes (CAACs) featuring alkene, ether, amine, imine, and phosphine functionalities. The stability of the free carbenes has been exploited for the synthesis of copper­(I) and gold­(I) complexes. It is shown that the pendant imine moiety stabilizes the gold­(III) oxidation state and enables the C–C bond oxidative addition of biphenylene to the corresponding cationic gold­(I) complex. The latter and the corresponding copper­(I) complex show high catalytic activity for the hydroarylation of α-methylstyrene with <i>N</i>,<i>N</i>-dimethylaniline, and the copper­(I) complex promotes the <i>anti</i>-Markovnikov hydrohydrazination of phenyl acetylene with high selectivity

Synthesis of Hemilabile Cyclic (Alkyl)(amino)carbenes (CAACs) and Applications in Organometallic Chemistry

A versatile methodology, involving readily available starting materials, allows for the synthesis of stable hemilabile bidentate cyclic (alkyl)­(amino)­carbenes (CAACs) featuring alkene, ether, amine, imine, and phosphine functionalities. The stability of the free carbenes has been exploited for the synthesis of copper­(I) and gold­(I) complexes. It is shown that the pendant imine moiety stabilizes the gold­(III) oxidation state and enables the C–C bond oxidative addition of biphenylene to the corresponding cationic gold­(I) complex. The latter and the corresponding copper­(I) complex show high catalytic activity for the hydroarylation of α-methylstyrene with <i>N</i>,<i>N</i>-dimethylaniline, and the copper­(I) complex promotes the <i>anti</i>-Markovnikov hydrohydrazination of phenyl acetylene with high selectivity

Reactivity of Scandium Terminal Imido Complex toward Boranes: C(sp³)–H Bond Borylation and B–O Bond Cleavage

Scandium terminal imido complex [(NNNN)­ScNDIPP] (<b>2</b>; NNNN = [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMeCH₂CH₂NMe₂)]⁻, DIPP = 2,6-^<i>i</i>Pr₂C₆H₃) reacts with 9-borabicyclononane (9-BBN) to give scandium borohydride [(NNNN­(B)­H)­Sc­(N­(H)­DIPP)] (<b>3</b>; NNNN­(B)H = [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMeCH₂CH₂N­(Me)­CH₂(BBN)]^2–), and C­(sp³)–H bond borylation of the NNNN ligand occurs during this reaction. In contrast, the reaction between complex <b>2</b> and catecholborane (CatBH) gives scandium catecholate [(NNNN)­Sc­(Cat)] (<b>4</b>), and B–O bond cleavage happens during this reaction. Both <b>3</b> and <b>4</b> have been well-characterized including the single-crystal X-ray diffraction analysis. Reaction of <b>2</b> with bis­(catecholato)­diboron (CatB–BCat) also gives a B–O bond cleavage product

Chameleon Behavior of a Newly Synthesized Scandium Nitrilimine Derivative

The synthesis, structural characterization, and reactivity of the first example of a scandium -substituted nitrilimine are presented. This unique complex exhibits high thermal stability but shows a rich reactivity toward a variety of unsaturated substrates, including aldehyde, ketone, nitrile, and allene derivatives. The versatility of the complex was further highlighted by density functional theory mechanistic studies

Chameleon Behavior of a Newly Synthesized Scandium Nitrilimine Derivative

The synthesis, structural characterization, and reactivity of the first example of a scandium -substituted nitrilimine are presented. This unique complex exhibits high thermal stability but shows a rich reactivity toward a variety of unsaturated substrates, including aldehyde, ketone, nitrile, and allene derivatives. The versatility of the complex was further highlighted by density functional theory mechanistic studies

Lewis Acid Triggered Reactivity of a Lewis Base Stabilized Scandium-Terminal Imido Complex: C–H Bond Activation, Cycloaddition, and Dehydrofluorination

A stable scandium-terminal imido complex is activated by borane to form an unsaturated terminal imido complex by removing the coordinated Lewis base, 4-(dimethylamino)­pyridine, from the metal center. The ensuing terminal imido intermediate can exist as a THF adduct and/or undergo cycloaddition reaction with an internal alkyne, C–H activation of a terminal alkene, and dehydrofluorination of fluoro-substituted benzenes or alkanes at room temperature. DFT investigations further highlight the ease of C–H activation for terminal alkene and fluoro­arene. They also shed light on the mechanistic aspects of these two reactions