Reactions of Alkynylsilanes with [RhCl(PPr-iso3)2]: The Synthesis of Four-Coordinate (Alkyne)-, Alkynyl-, and Vinylidenerhodium(I) and Five- and Six-Coordinate Alkynylhydridorhodium(III) Complexes from RC.tplbond.CSiMe3, Me3SiC.tplbond.CSiMe3, and HC.tplbond.CSiMe3

Werner, Helmut; Baum, Matthias; Schneider, Dietrich; Windmueller, B.

doi:10.1021/om00016a013

Cited by 129 publications

(34 citation statements)

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“…These findings were pivotal in the development of the "oxidative-addition" pathway for the formation of metal vinylidene complexes. [25,[40][41][42][43][44][45][46] Despite the initial reports in this area being published over 25 years ago, the precise mechanism that connects the three compounds has been the subject of a considerable number of recent experimental and theoretical studies. Much of this work has been focused specifically on the conversion of the alkynyl hydride species to the corresponding vinylidene complexes.…”

Section: In a Series Of Pioneering Studies Werner Established That Tmentioning

confidence: 99%

Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes

Lynam

2010

Chemistry A European J

155

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Transition-metal vinylidene complexes are intermediates in a number of synthetically important transformations of alkynes. Underpinning these applications is the ability of various electron-rich transition-metal complexes to effectively facilitate the conversion of alkynes into their vinylidene tautomers. Recent experimental and theoretical studies have provided considerable insight into the mechanisms by which this process occurs and they are detailed herein. In particular, it has been demonstrated that different substituents on both the metal and the alkyne may have profound effects on both the kinetic and thermodynamic profiles of the alkyne/vinylidene tautomerisation. An important finding is that internal alkynes may be employed to prepare disubstituted vinylidene complexes under easily accessible conditions. This discovery brings to light a new facet of the potential synthetic applications of transition metal vinylidene complexes.

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Section: In a Series Of Pioneering Studies Werner Established That Tmentioning

confidence: 99%

Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes

Lynam

2010

Chemistry A European J

155

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“…a) Hydrtdo region of the in situ 500 MHz 'H NMR spectrum of 4 (13.8 bar HJCO, 22°C); b) broadband phosphorus-decoupled 'H{"P} NMR spectrum of 4 under the same conditions.of 164 Hz is not caused by trans 'J(P,H) coupling, as seen in virtually all other H-Rh'Rh"'-P complexes, but rather, is due to 'J(Rh, H) coupling! ["I There are hundreds of rhodium hydrido complexes known and their 'J(Rh,H) coupling constants are typically small and vary from almost 0 to 50.8 Hz [16]. The 'J(Rh.…”

mentioning

confidence: 99%

Bimetallic Hydroformylation Catalysis: In Situ Characterization of a Dinuclear Rhodium(II) Dihydrido Complex with the Largest Rh–HNMR Coupling Constant

Matthews¹,

Howell²,

Peng³

et al. 1996

Angew. Chem. Int. Ed. Engl.

105

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COMMUNICATIONS T = 25 "C, t = 3.5 h) also showed that complex 1 is able to perform more than 36 000 (yield 99.9 YO) without loss of activity.In order to rule out the participation in the catalysis of free, solvated [Rh(PPh,),]+ or similar cationic species formed by dissociation of complex 1, two independent experiments were made. First. the addition of four equivalents of Cs-2 did not alter the rate of reaction, which suggests that the common ion effect is absent. Second, hydrogenation experiments with added D,O provided further evidence to eliminate this hypothesis. If [Rh(PPh,),]+ or a related species were present, partially deuterated hexane would be found.["' By GC-MS analysis it was shown that the hexane formed in the reaction was not deuterium-enriched.The first e.w-monothiocarborane rhodium complex has been synthesized, and it catalyzed the hydrogenation of 1 -hexene eight times faster than Wilkinson's catalyst. The thioether group directly bonded to the cluster's open face enables discrimination between upper and lower belt B-H groups, leading to the formation of a B(l I)-H-Rh bond. This supports the initial hypothesis that the favoring of an exo-nido upper-belt form would readily enhance the hydrogenation activity of a rhodacarborane molecule. Experimental Procedure

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“…Since the alkyne-vinylidene isomerization is af acile process in the rhodium-catalyzed reaction of internal silyl alkynes, [10] the reaction of disilyl diyne 1m in the presence of the cationic rhodium(I)/biphep catalyst is of interest. At room temperature,t he reaction proceeded sluggishly to give the corre-sponding alkynylmethylidene-benzoxasilole 2m in low yield.…”

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confidence: 99%

“…Diyne 1 reacts with ac ationic rhodium(I) complex to generate rhodium vinylidene A through oxygenassisted 1,2-silicon migration. [10,13] Subsequent 1,3-alkyne migration via hypervalent silicon B [14] affords alkenylrhodium C-1 or p-allenylrhodium C-2.Protodemetalation of C-1 or C-2 affords alkynylmethylidene-benzoxasilole 2.Inthe reaction of disilyl diynes 1m-o,t here may be equilibration between two possible rhodium vinylidenes A and D,b ut the phenol oxygen cannot attack at the vinylidene a-carbon and silicon atoms in intermediate D.Alkynylmethylidene-benzoxasiloles 2m-o might thus be generated via intermediate A at elevated temperature.…”

mentioning

confidence: 99%

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Synthesis of Alkynylmethylidene‐benzoxasiloles through a Rhodium‐Catalyzed Cycloisomerization Involving 1,2‐Silicon and 1,3‐Carbon Migration

et al. 2017

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It is shown that ac ationic rhodium(I)/biphep complex catalyzest he cycloisomerization of 2-(alkynylsilylethynyl)phenols,leading to alkynylmethylidene-benzoxasiloles through concomitant silicon and carbon migration. This unprecedented cycloisomerization presumably proceeds via the formation of rhodium vinylidenes through 1,2-silicon migration, followed by 1,3-carbon (alkyne) migration via the formation of hypervalent silicon centers.

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Reactions of Alkynylsilanes with [RhCl(PPr-iso3)2]: The Synthesis of Four-Coordinate (Alkyne)-, Alkynyl-, and Vinylidenerhodium(I) and Five- and Six-Coordinate Alkynylhydridorhodium(III) Complexes from RC.tplbond.CSiMe3, Me3SiC.tplbond.CSiMe3, and HC.tplbond.CSiMe3

Cited by 129 publications

References 0 publications

Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes

Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes

Bimetallic Hydroformylation Catalysis: In Situ Characterization of a Dinuclear Rhodium(II) Dihydrido Complex with the Largest Rh–HNMR Coupling Constant

Synthesis of Alkynylmethylidene‐benzoxasiloles through a Rhodium‐Catalyzed Cycloisomerization Involving 1,2‐Silicon and 1,3‐Carbon Migration

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