Mononuclear and dinuclear iridium and heterodinuclear iridium–rhodium complexes derived from 1,4-C6H4(CCSiMe3)2 as precursor

Lass, Raimund W.; Werner, Helmut

doi:10.1016/j.ica.2010.09.055

“…Consequently, vinylidene complexes are attractive candidates as intermediates for the transition-metal-catalyzed transformation of alkynes . The heteroatom-substituted internal alkynes R–CC–E (E = SiR 3 , SnR 3 , SR, SeR, Br, I , ) can also participate in such vinylidene formation via the migration of an E group, and, in some cases, silylvinylidenes thus formed are known to undergo the reverse reaction, rearrangement of the η 1 -silylvinylidenes into the corresponding η 2 -silylalkynes at certain metal complexes. , …”

Section: Introductionmentioning

confidence: 99%

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η¹-Disubstituted Vinylidene and η²-Internal Alkyne

Mutoh

¹

,

Kimura

²

,

Ikeda

³

et al. 2012

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The reaction of diphenylacetylene at a cationic ruthenium complex with a dppm (Ph2PCH2PPh2) ligand, [CpRu(dppm)]+, has been studied to reveal essentially for the first time the existence of an equilibrium between an η2-internal alkyne and η1-disubstituted vinylidene at a transition metal center. The reaction mixture at 70 °C for 69 h unexpectedly afforded a coupling product of diphenylacetylene and the dppm ligand, an (alkenylphosphonio)phenyl complex [CpRu{Ph2PCH2P(C6H4)Ph(η2-C(Ph)CHPh)}]+ with the extremely rare coordination mode of κ1 P,η1 C,η2 C,C′. The (alkenylphosphonio)phenyl complex further undergoes inversion of the coordination face of the alkene moiety at p-xylene reflux temperature. Both isomers of (alkenylphosphonio)phenyl complexes as well as the intermediary η2-internal alkyne and η1-disubstituted vinylidene complexes were fully characterized spectroscopically and crystallographically. By considering the structure of the (alkenylphosphonio)phenyl complexes obtained, the coupling reaction has been proposed to involve the attack of a phosphorus atom on the coordinated diphenylacetylene, which is in equilibrium with an η1-diphenylvinylidene ligand, and the C–H bond activation of a phenyl group on the cationic phosphorus atom leading to the products. Theoretical calculations support the proposed mechanism.

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Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

Suzuki

¹

,

Wu

²

,

Lin

³

et al. 2021

Angewandte Chemie

1

0

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This manuscript describes the first example of an alkyne insertion to the Au−B bond of a di(o‐tolyl)borylgold complex to afford a cis‐2‐borylalkenylgold complex, and its isomerization to result in interchanging substituents on the alkenyl carbon atom and the boron atom. The former reaction is the first example of an alkyne insertion to a Au−B bond. In the latter reaction, the regiochemistry of the isomerized alkenylgold products varied depending on the substituents. DFT calculations revealed the formation of gold alkynylborates as a common intermediate via a “retro‐1,2‐metalate shift”, which can be considered as an anti‐β‐carbon/silicon elimination, and identified a subsequent 1,2‐metalate shift as the regiochemistry‐determining step. Relative energies of the transition states to each isomer and natural‐bond‐orbital (NBO) analyses were used to clearly rationalize the regiochemistry of the products.

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Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

Suzuki

¹

,

Wu

²

,

Lin

³

et al. 2021

View full text Add to dashboard Cite

This manuscript describes the first example of an alkyne insertion to the Au−B bond of a di(o‐tolyl)borylgold complex to afford a cis‐2‐borylalkenylgold complex, and its isomerization to result in interchanging substituents on the alkenyl carbon atom and the boron atom. The former reaction is the first example of an alkyne insertion to a Au−B bond. In the latter reaction, the regiochemistry of the isomerized alkenylgold products varied depending on the substituents. DFT calculations revealed the formation of gold alkynylborates as a common intermediate via a “retro‐1,2‐metalate shift”, which can be considered as an anti‐β‐carbon/silicon elimination, and identified a subsequent 1,2‐metalate shift as the regiochemistry‐determining step. Relative energies of the transition states to each isomer and natural‐bond‐orbital (NBO) analyses were used to clearly rationalize the regiochemistry of the products.

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Mononuclear and dinuclear iridium and heterodinuclear iridium–rhodium complexes derived from 1,4-C6H4(CCSiMe3)2 as precursor

Cited by 9 publications

References 34 publications

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η¹-Disubstituted Vinylidene and η²-Internal Alkyne

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η¹-Disubstituted Vinylidene and η²-Internal Alkyne

Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

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Mononuclear and dinuclear iridium and heterodinuclear iridium–rhodium complexes derived from 1,4-C6H4(CCSiMe3)2 as precursor

Cited by 9 publications

References 34 publications

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η1-Disubstituted Vinylidene and η2-Internal Alkyne

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η1-Disubstituted Vinylidene and η2-Internal Alkyne

Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

Isomerization of a cis‐(2‐Borylalkenyl)Gold Complex via a Retro‐1,2‐Metalate Shift: Cleavage of a C−C/C−Si Bond trans to a C−Au Bond

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Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η¹-Disubstituted Vinylidene and η²-Internal Alkyne

Formation of (Alkenylphosphonio)phenylruthenium Complexes from Diphenylacetylene and a [CpRu(dppm)] Cation: Experimental Evidence for the Equilibrium between η¹-Disubstituted Vinylidene and η²-Internal Alkyne