Synthesis, Properties, and Catalytic Applications of Caged, Compact Trialkylphosphine 4-Phenyl-1-phospha-4-silabicyclo[2.2.2]octane

Ochida, Atsuko; Hamasaka, Go; Yamauchi, Yasuki; Kawamorita, Soichiro; Oshima, Naoya; Hara, Kenji; Ohmiya, Hirohisa; Sawamura, Masaya

doi:10.1021/om8005728

Cited by 34 publications

(29 citation statements)

References 36 publications

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“…The reported data and further experiments provided evidence for a rhodium species only coordinated by one phosphine of [silica]-SMAP (10). 61,62 This trend was also seen in other publications where very bulky monodentate phosphines and isocyanides were used in homogeneous systems and proved to be very efficient ligands in rhodium-catalyzed hydrosilylation of ketones. 63−66 Very recently, research has focused on the application of rhodium-catalyzed hydrosilylation in ionic liquids.…”

Section: N-heterocyclicsupporting

confidence: 65%

Rhodium-Catalyzed Hydrosilylation of Ketones: Catalyst Development and Mechanistic Insights

et al. 2012

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The current status of rhodium-catalyzed hydrosilylation of ketones is reviewed, focusing on development milestones leading to state of the art chiral ligand systems and mechanistic understanding. Four ligand classes are discussed: phosphorus-, nitrogen-, mixed-donor ligand-as well as N-heterocyclic carbene-based ligand systems. Results relevant for a mechanistic understanding of the reaction are presented, starting from the initial investigations by Ojima, limitations of the first mechanistic picture leading to the Zheng-Chan mechanism, which was recently replaced by a silylene-based mechanism introduced by Hofmann and Gade.

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Section: N-heterocyclicsupporting

confidence: 65%

Rhodium-Catalyzed Hydrosilylation of Ketones: Catalyst Development and Mechanistic Insights

et al. 2012

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“…Hara and Sawamura [30][31][32][33] prepared compact phosphane molecules (A) arrayed on a single-crystal Au surface (B), to which an Rh complex was coordinated (C) [34]. The caged, compact trialkylphosphane 1-phospha-4-silabicyclo[2.2.2]octane (SMAP, silicon-constrained monodentate alkylphosphane) [30] bearing an alkanethiolate pendant group forms a self-assembled monolayer on the Au surface (Figure 7.1).…”

Section: Assembled Monolayers Of Metal Complexes On Single-crystal Sumentioning

confidence: 99%

Site‐Isolated Heterogeneous Catalysts

Tada

Muratsugu

2013

Heterogeneous Catalysts for Clean Technology

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IntroductionNumerous supported metal catalysts have been utilized for a variety of chemical processes, and their crucial advantages are (i) easy separation of the catalyst and reaction medium, (ii) high durability of the catalyst, and (iii) unique catalytic performance from that of homogeneous analogs. The structures of homogeneous catalysts have been thoroughly studied in organometallic and coordination chemistry, wherein catalytic behavior can be regulated by tuning the ligands of homogeneous metal complexes. In contrast, the heterogeneity and complexity of support surfaces often hinder full understanding of relationships between catalytically active structures and reactivity for heterogeneous catalysts. Regulating catalytic performance at the molecular level therefore remains more difficult for heterogeneous supported metal catalysts compared with their homogenous analogs.To construct well-controlled metal coordination structures for selective catalysis, attachment techniques for metal complexes have been developed, and various homogeneous precursors have been chemically attached to support surfaces in a controllable manner [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. There are several types of attachment techniques: coordination of metal-complex precursors to immobilized ligands on organic polymers [17][18][19][20][21], coordination of metal-complex precursors to functional ligands bound to oxide surfaces [2,4,[22][23][24][25], intercalation into clay materials [26], ion exchange into porous materials such as zeolites and mesoporous silicas [27], and direct attachment of metal-complex precursors onto oxide surfaces [3,6,11,28,29]. The selective immobilization of a homogeneous metal complex can isolate each metal site on a support surface, resulting in the formation of a well-defined single-site catalyst. The interaction between a supported metal complex and support surface often produces a unique metal coordination structure, different from that of a homogeneous counterpart. Consequently, unique catalytic performance can be obtained on the surface.In this chapter, several recent examples of site-isolated heterogeneous catalysts on solid support surfaces are highlighted. The coordination structures of siteisolated supported metal complexes, their unique catalytic performance, and their Heterogeneous Catalysts for Clean Technology: Spectroscopy, Design, and Monitoring, First Edition. Edited

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“…[35] 232 Hz for [W(CO) 5 (PtBu 3 )] [36] and [W(CO) 5 (PCy 3 )], [16] and 240 Hz for [W(CO) 5 (PPh 2 Et)] [37] but contrasts somewhat with that of 280 Hz seen for [W(CO) 5 (PPh 3 )]. [36] The solution 31 [38] It is noteworthy that a related bicyclic 4-silaphosphinane complex has a lower 1 J P-Rh coupling constant of 117.8 Hz [39] while a phenyl-phosphatrioxaadamantane derivative has a higher value of 133 Hz. [40] Carbonyl stretching frequencies in the infrared spectra of phosphane containing complexes have long been used as a measure of the donating properties of phosphanes.…”

Section: Spectroscopic and Electronic Properties Of 2 3 4 Andmentioning

confidence: 99%

Metal Complexes of a Structurally Embellished Phosphinane Ligand: An Assessment of Stereoelectronic Effects

et al. 2011

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The stereoelectronic features of the pentacyclic phosphane (1S,4R,4aS,5aR,6R,9S,9aS,10aR)‐4,6,11,11,12,12‐hexamethyl‐10‐phenyldodecahydro‐1,4:6,9‐dimethanophenoxaphosphinine (phenop) have been explored through a range of empirical methods including single‐crystal X‐ray structure determinations of the sulfide derivative phenopS (1), the selenide phenopSe (2), [Fe(CO)4(κ1‐phenop)] (3), [W(CO)5(κ1‐phenop)] (4) and trans‐[Rh(κ1‐phenop)(CO)Cl] (5). Cone angles derived from the structural data range from 164–203° with the smaller values being observed for the compounds possessing a phenyl group that is orthogonal to the P–Z bond and the larger values for the compounds expressing a parallel phenyl ring orientation. The cone angle data suggest a moderately bulky phosphane comparable, in steric terms, to PCy3. This is further borne out on inspection of the M–P bond lengths which tend towards the longer end of the known scale. Some flexibility is observed in the central ring which approximates to a boat conformation at one extreme and an envelope at the other depending on the nature of the P‐substituent. The electronic properties of κ1‐phenop have been assessed using a combination of infrared and NMR spectroscopy. The absolute value of the one‐bond coupling constants 1JP‐Se and 1JP‐Rh are very close to those reported for PPh3, suggesting a close analogy between κ1‐phenop and the well known triphenylphosphane. In addition, relevant υ(CO) stretches in the IR spectra of the metal carbonyl complexes also closely mimic those for the analogous complexes containing PPh3. These conclusions are supported by molecular electrostatic potential calculations at the DFT level which place phenop close to PPh3 in terms of lone pair availability.

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Synthesis, Properties, and Catalytic Applications of Caged, Compact Trialkylphosphine 4-Phenyl-1-phospha-4-silabicyclo[2.2.2]octane

Cited by 34 publications

References 36 publications

Rhodium-Catalyzed Hydrosilylation of Ketones: Catalyst Development and Mechanistic Insights

Rhodium-Catalyzed Hydrosilylation of Ketones: Catalyst Development and Mechanistic Insights

Site‐Isolated Heterogeneous Catalysts

Metal Complexes of a Structurally Embellished Phosphinane Ligand: An Assessment of Stereoelectronic Effects

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