Dual nucleophilic substitution at a W(<scp>ii</scp>) η<sup>2</sup>-coordinated diiodo acetylene leading to an amidinium carbyne complex

Helmdach, Kai; Rüger, Julia; Villinger, Alexander; Seidel, Wolfram W.

doi:10.1039/c5cc10397e

Cited by 7 publications

(3 citation statements)

References 48 publications

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“…In this paper, we present a general procedure to generate W(II) alkyne complexes with nitrogen substitution in the α-position via the nucleophilic substitution of one bromine substituent at a coordinated bromoalkyne. In contrast to recent investigations with a diiodoacetylene complex, nucleophilic substitution is possible while a rearrangement of the alkyne moiety to an aminocarbenium carbyne complex is avoided . In addition, deprotonation of the secondary amine group at the coordinated alkyne does not inevitably lead to a metal assisted C/C bond cleavage forming an isocyanide ligand.…”

Section: Discussionmentioning

confidence: 87%

“…In contrast to recent investigations with a diiodoacetylene complex, nucleophilic substitution is possible while a rearrangement of the alkyne moiety to an aminocarbenium carbyne complex is avoided. 60 In addition, deprotonation of the secondary amine group at the coordinated alkyne does not inevitably lead to a metal assisted C/C bond cleavage forming an isocyanide ligand. This stability can be attributed to the absence of a labile ligand in the complex.…”

Section: ■ Conclusionmentioning

confidence: 99%

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Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

et al. 2019

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Recently, alkyne complexes with terminal thiolate/ amide substitution have been shown to act as S,N-chelate ligands in dinuclear complexes. In this study, the detailed synthesis and reactivity of W(II) alkyne complexes bearing different amino groups in the α-position are reported. The preparative scheme starts with cationic alkyne complexes [Tp′W(CO) 2 -η 2 -C,C′-C 2 Br(SR)]PF 6 {Tp′ = hydridotris(3,5-dimethylpyrazolyl)borate, R = benzyl (Bn), C 2 H 4 SiMe 3 }, which are obtained by applying free bromo alkynes. Subsequent nucleophilic substitution of the bromine substituent led to unsymmetrical substituted alkyne complexes [Tp′W(CO) 2 -η 2 -C,C′-C 2 (SR)(NHBn)]PF 6 with S,N substitution in the α position of the coordinated alkyne. Depending on the base used, deprotonation of the secondary amine resulted in either neutral iminoketenyl complexes [Tp′W(CO) 2 -η 2 -C,C′-C 2 (SR)(NBn)] or a zwitterionic PF 5 adduct. Reductive removal of the benzyl protective group was primarily observed at the imine substituent, causing a side-on/end-on rearrangement to the cyanide substituted carbene complex K[Tp′W(CO) 2 -η 1 -C(CN)(SBn)]. The reversibility of the rearrangement was proven with HBF 4 /Et 2 O, because double protonation led to [Tp′W(CO) 2 -η 2 -C,C′-C 2 (SR)(NH 2 )]BF 4 exhibiting an unprecedented primary amine substitution at the coordinated alkyne. The reaction sequence starting with the thiol SC 2 H 4 SiMe 3 derivative leading to the desired [Tp′W(CO) 2 -η 2 -C,C′-C 2 S(NHBn)] with a terminal S atom as well as the bonding situation in those complexes is discussed based on full spectroscopic characterization including X-ray structure analyses. Finally, a trinuclear complex assembled by homoleptic coordination of Pd(II) by two anionic S,N-chelates [Tp′W(CO) 2 -η 2 -C,C′-C 2 S(NBn)] − is presented.

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Section: Discussionmentioning

confidence: 87%

Section: ■ Conclusionmentioning

confidence: 99%

Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

et al. 2019

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“…Classic synthetic strategies toward transition metal vinylidene complexes rely on the transformation of organometallic species such as metal π‐alkyne, [10] σ‐alkynyl, [33] carbyne, [34,35] and acyl complexes [19] . Isomerization of π‐alkyne complexes derived from terminal alkynes to generate a number of metal vinylidene complexes has been studied extensively [13,16,17,20] .…”

Section: Resultsmentioning

confidence: 99%

One‐Pot Synthesis of High‐Strained Metal Vinylidene and Metal Carbyne

Huang

Yan

Zheng

et al. 2022

Chemistry A European J

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A novel one-pot reaction producing a metal vinylidene structure in a five-membered ring by cyclization of a multiyne has been achieved. The ring strain and the high stability of the cyclic metal vinylidene complexes have been analyzed experimentally and computationally. The metal vinylidene unit in a fused-ring complex is unreactive to both nucleophiles and electrophiles. It reacts however at the nearby carbonyl group achieving the unprecedented conversion of metal tributing factors for the aromaticity-driven process has been studied by DFT calculations.

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Facile Synthesis of a Stable Side‐on Phosphinyne Complex by Redox Driven Intramolecular Cyclisation

Lange

Schröder

Oberem

et al. 2020

Chemistry A European J

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Alkyne complexes with vicinal substitution by a Lewis acid and a Lewis base at the coordinated alkyne are prospective frustrated Lewis pairs exhibiting a particular mutual distance and, hence, a specific activation potential. In this contribution, investigations on the generation of a WII alkyne complex bearing a phosphine as Lewis base and a carbenium group as Lewis acid are presented. Independently on potential substrates added, an intramolecular cyclisation product was always isolated. A subsequent deprotonation step led to an unprecedented side‐on λ5‐phosphinyne complex, which is interpreted as highly zwitterionic according to visible absorption spectroscopy supported by TD‐DFT. Low‐temperature 31P NMR and EPR spectroscopic measurements combined with time‐dependent IR‐spectroscopic monitoring provided insights in the mechanism of the cyclisation reaction. Decomposition of the multicomponent IR spectra by multivariate curve resolution and a kinetic hard‐modelling approach allowed the derivation of kinetic parameters. Assignment of the individual IR spectra to potential intermediates was provided by DFT calculations.

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Dual nucleophilic substitution at a W(ii) η²-coordinated diiodo acetylene leading to an amidinium carbyne complex

Cited by 7 publications

References 48 publications

Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

One‐Pot Synthesis of High‐Strained Metal Vinylidene and Metal Carbyne

Facile Synthesis of a Stable Side‐on Phosphinyne Complex by Redox Driven Intramolecular Cyclisation

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Dual nucleophilic substitution at a W(ii) η2-coordinated diiodo acetylene leading to an amidinium carbyne complex

Cited by 7 publications

References 48 publications

Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

Pathways to Polynuclear Complexes with α-S,N-Substituted Alkynes as Bridging Ligands

One‐Pot Synthesis of High‐Strained Metal Vinylidene and Metal Carbyne

Facile Synthesis of a Stable Side‐on Phosphinyne Complex by Redox Driven Intramolecular Cyclisation

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Dual nucleophilic substitution at a W(ii) η²-coordinated diiodo acetylene leading to an amidinium carbyne complex