Reactions of Stable <i>N</i>-Heterocyclic Silylenes with Ketones and 3,5-Di-<i>tert</i>-butyl-<i>o</i>-benzoquinone

The reactions of L [PhC(NtBu)2SiCl] and L′ [CH{(CCH2)(CMe)(2,6-iPr2C6H3N)2}Si] with monoketones and quinone have been examined. The reaction of L with 2-adamantanone furnishes a [1 + 2]–cycloaddition product 1, whereas with 3,5-di-tert-butyl-o-benzoquinone leads to the [1 + 4]–cycloaddition product 2. The treatment of L′ with 3,5-di-tert-butyl-o-benzoquinone gives [1 + 4]–cycloaddition product 3, and the reaction with acylferrocene yields compound 4. Compounds 1–4 were characterized by single crystal X-ray structural analysis, NMR spectroscopy, EI–MS spectrometry, and elemental analysis

Regiospecific C–H Bond Activation: Reactivity Study of N-Heterocyclic Silylene toward Ambidentate Phosphorus Ylide

The reaction of two highly reactive species, the silylene [CH{C(Me)NAr}{C(CH2)NAr}Si] (L, Ar = 2,6-iPr2C6H3) and the phosphorus ylide MeC(O)CHPPh3, resulted in the formation of 1, involving regiospecific Calkyl–H bond activation. Compound 1 was characterized by elemental analysis and multinuclear NMR and unambiguously by single-crystal X-ray structural analysis

Regiospecific C–H Bond Activation: Reactivity Study of N-Heterocyclic Silylene toward Ambidentate Phosphorus Ylide

The reaction of two highly reactive species, the silylene [CH{C(Me)NAr}{C(CH2)NAr}Si] (L, Ar = 2,6-iPr2C6H3) and the phosphorus ylide MeC(O)CHPPh3, resulted in the formation of 1, involving regiospecific Calkyl–H bond activation. Compound 1 was characterized by elemental analysis and multinuclear NMR and unambiguously by single-crystal X-ray structural analysis

Syntheses of Group 7 Metal Carbonyl Complexes with a Stable N-Heterocyclic Chlorosilylene

Two structurally characterized manganese [L2Mn(CO)4]+[Mn(CO)5]− (1) and rhenium [L3Re(CO)3]+[ReCO)5]− (2) silylene complexes were prepared in one pot syntheses by reacting 1 equivalent of Mn2(CO)10 with 2 equivalents of stable N-heterocyclic chlorosilylene L {L = PhC(NtBu)2SiCl} and 1 equivalent of Re2(CO)10 with 3 equivalents of L in toluene at room temperature. Both complexes 1 and 2 were characterized by single-crystal X-ray structural analysis, NMR and IR spectroscopy, EI-MS spectrometry, and elemental analysis

Syntheses of Group 7 Metal Carbonyl Complexes with a Stable N-Heterocyclic Chlorosilylene

Two structurally characterized manganese [L2Mn(CO)4]+[Mn(CO)5]− (1) and rhenium [L3Re(CO)3]+[ReCO)5]− (2) silylene complexes were prepared in one pot syntheses by reacting 1 equivalent of Mn2(CO)10 with 2 equivalents of stable N-heterocyclic chlorosilylene L {L = PhC(NtBu)2SiCl} and 1 equivalent of Re2(CO)10 with 3 equivalents of L in toluene at room temperature. Both complexes 1 and 2 were characterized by single-crystal X-ray structural analysis, NMR and IR spectroscopy, EI-MS spectrometry, and elemental analysis

A Remarkable End-On Activation of Diazoalkane and Cleavage of Both C–Cl Bonds of Dichloromethane with a Silylene to a Single Product with Five-Coordinate Silicon Atoms

The 1:1 reaction of benzamidinato-stabilized chlorosilylene PhC­(N<i>t</i>Bu)₂SiCl (<b>1</b>) with CH­(SiMe₃)­N₂ resulted in the formation of colorless [PhC­(N<i>t</i>Bu)₂Si­(Cl)­{N₂CH­(SiMe₃)}]₂ (<b>2</b>), which consists of a four-membered Si₂N₂ ring. Surprisingly, N₂ elimination from the diazoalkane did not occur, but rather an end-on activation of the nitrogen was observed. For the mechanism, we propose the formation of a silaimine complex <b>A</b> as an intermediate, which is formed during the reaction and dimerized under [2 + 2] cycloaddition to <b>2</b>. In contrast, treatment of <b>1</b> with dichloromethane afforded a 2:1 product, [{PhC­(N<i>t</i>Bu)₂Si­(Cl₂)}₂CH₂] (<b>3</b>), which is obviously formed by oxidative addition under cleavage of both C–Cl bonds and formation of two Si–Cl and two Si–C bonds. Both silicon atoms in <b>3</b> are five-coordinate. Compounds <b>2</b> and <b>3</b> were characterized by single-crystal X-ray studies, multinuclear NMR spectroscopy, and EI-mass spectrometry

A Remarkable End-On Activation of Diazoalkane and Cleavage of Both C–Cl Bonds of Dichloromethane with a Silylene to a Single Product with Five-Coordinate Silicon Atoms

The 1:1 reaction of benzamidinato-stabilized chlorosilylene PhC­(N<i>t</i>Bu)₂SiCl (<b>1</b>) with CH­(SiMe₃)­N₂ resulted in the formation of colorless [PhC­(N<i>t</i>Bu)₂Si­(Cl)­{N₂CH­(SiMe₃)}]₂ (<b>2</b>), which consists of a four-membered Si₂N₂ ring. Surprisingly, N₂ elimination from the diazoalkane did not occur, but rather an end-on activation of the nitrogen was observed. For the mechanism, we propose the formation of a silaimine complex <b>A</b> as an intermediate, which is formed during the reaction and dimerized under [2 + 2] cycloaddition to <b>2</b>. In contrast, treatment of <b>1</b> with dichloromethane afforded a 2:1 product, [{PhC­(N<i>t</i>Bu)₂Si­(Cl₂)}₂CH₂] (<b>3</b>), which is obviously formed by oxidative addition under cleavage of both C–Cl bonds and formation of two Si–Cl and two Si–C bonds. Both silicon atoms in <b>3</b> are five-coordinate. Compounds <b>2</b> and <b>3</b> were characterized by single-crystal X-ray studies, multinuclear NMR spectroscopy, and EI-mass spectrometry

Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si–Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN(SiMe3)2, L= PhC(NtBu)2) (2) has been synthesized by the reaction of LSiHCl2 with KN(SiMe3)2 in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlorinating agent. 2 exhibits a high stability up to 154 °C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si–Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, EI-mass spectrometry, and single crystal X-ray diffraction studies

Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si–Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN(SiMe3)2, L= PhC(NtBu)2) (2) has been synthesized by the reaction of LSiHCl2 with KN(SiMe3)2 in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlorinating agent. 2 exhibits a high stability up to 154 °C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si–Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, EI-mass spectrometry, and single crystal X-ray diffraction studies

Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si–Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN(SiMe3)2, L= PhC(NtBu)2) (2) has been synthesized by the reaction of LSiHCl2 with KN(SiMe3)2 in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlorinating agent. 2 exhibits a high stability up to 154 °C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si–Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, EI-mass spectrometry, and single crystal X-ray diffraction studies