Quantifying the Electronic Effect of Substituted Phosphine Ligands via Molecular Electrostatic Potential

Suresh, Cherumuttathu H.; Koga, Nobuaki

doi:10.1021/ic0109400

Cited by 169 publications

(156 citation statements)

References 43 publications

Supporting

Mentioning

153

Contrasting

Unclassified

Order By: Relevance

“…11 Crabtree et al reported a scheme for quantifying the electronic impact of different phosphines using ab initio calculations on Ni(CO) 3 (PR 3 ) complexes. 12 Koga et al 13 focused on PR 3 ligands in order to develop metal-independent measures of electronic character. Pittard and co-workers used PM3(tm) quantum mechanics to evaluate semiempirical electronic parameters (SEP) for phosphines ligated to Mo(CO) 5 (PR 3 ), W(CO) 5 (PR 3 ), and CpRh(CO)(PR 3 ).…”

Section: Introductionmentioning

confidence: 99%

A Priori Assessment of the Stereoelectronic Profile of Phosphines and Phosphites

et al. 2003

View full text Add to dashboard Cite

This research has demonstrated the utility of a rigorously calibrated, molecular mechanics/ semiempirical quantum mechanical protocol for developing stereoelectronic (Tolman) maps for phosphine ligands. A computational analysis of alkyl and aryl phosphines in common usage suggests that these ligands are quite similar stereoelectronically. A noticeable gap in the Tolman map for common phosphines is observed for large, electron-poor phosphines. Several candidates meeting these criteria were identified, the most promising of which is P(t-C 4F9)3. Phosphines in which the phosphorus participates in a ring, which comprise a very small subset of reported phosphines, have very interesting stereoelectronic properties, particularly those in which the ligating phosphorus is part of a three-membered ring. In terms of steric properties, the symmetric deformation coordinate proposed by Orpen and co-workers on the basis of crystallographic studies is calculated with sufficient accuracy using PM3(tm) to allow good confidence in predictions of novel phosphines. For quantification of the electronic properties of phosphines, we analyzed changes in the CO stretching frequency upon changing the ancillary phosphine ligands.

show abstract

Section: Introductionmentioning

confidence: 99%

A Priori Assessment of the Stereoelectronic Profile of Phosphines and Phosphites

et al. 2003

View full text Add to dashboard Cite

show abstract

“…In numerous studies pursuing the efficient synthesis of Ph-SMAP (1a) (the parent compound for various SMAP-type compounds), we have developed a route that uses benzylphosphine (12) as a source of the P atom as shown in Scheme 1. Thus, phenyltrivinylsilane (10), which was prepared from PhSiCl 3 and vinylmagnesium bromide, was converted into tribromide 11 through anti-Markovnikov HBr addition.…”

Section: Synthesismentioning

confidence: 99%

“…12 A larger negative V min value corresponds to a stronger electron-donating ability of a phosphine. The V min (∫43.14 kcal/mol) of Ph-SMAP is much more negative than the value of monoaryldialkylphosphine PhMe 2 P and is in the range for trialkylphosphines, being between the values of Me 3 P and Et 3 P (see also Figure 8).…”

Section: Structure and Propertiesmentioning

confidence: 99%

“…20 Calculations of V min (kcal/mol) values 12 indicated that the donor powers of 4-MeO-Ph-SMAP (1c) and 4-Me-Ph-SMAP (1d) were apparently stronger than those of Me 3 P and Ph-SMAP (1a), and comparable with those of Bu 3 P and (i-Pr) 3 P. The Me 2 N group causes a much larger effect, increasing the donor ability of 4-Me 2 N-Ph-SMAP (1b) even more than (t-Bu) 3 P. In contrast, substitution at the para-position with an electron-withdrawing group decreased donor power; the donating power of 4-Cl-Ph-SMAP (1e) and 4-CF 3 -Ph-SMAP (1f) were comparable with monoaryl-dialkylphosphine Me 2 PhP. The donor power of 3,5-(CF 3 ) 2 -Ph-SMAP (1g) is as weak as that of MePh 2 P. The substitution effect at the para-position of Ph-SMAP on V min is proportional to Hammett's substituent constant s. …”

Section: Electronic Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Air-Stable, Compact, Caged Trialkylphosphines (SMAPs): Synthesis, Properties and Applications to Homogeneous and Heterogeneous Catalysis

Sawamura

2009

J. Synth. Org. Chem. Jpn.

View full text Add to dashboard Cite

Synthesis, properties and applications to transition metal catalysis of extremely compact, caged trialkylphosphines (SMAPs) in the form of molecules or silica-supported materials are described. The new phosphines are air-stable despite their strongly electron-rich character. Soluble phosphine Ph-SMAP showed high ligand performance in the Rh-catalyzed hydrosilylation and hydrogenation of ketones. The silica-supported SMAP (Silica-SMAP) displayed a unique coordination behavior to form 1:1 P-metal complexes, which appeared to be useful as platforms to create highly active catalytic centers. As a result, Silica-SMAP enabled the Rh-catalyzed hydrosilylation and hydrogenation of extremely hindered ketones such as di-tert-butyl ketone as well as Ir-catalyzed directed ortho-borylation of functionalized arenes with a broad substrate scope.

show abstract

“…We optimized the geometry of Ph-SMAP ( Figure 4a) and evaluated donor ability by the value of the molecular electrostatic potential minimum V min (kcal·mol -1 ) according to Koga's method. 18 A larger negative V min value corresponds to stronger electron-donating ability of a phosphine. For comparison, we also performed calculations for 4-phenyl-1-phosphabicyclo[2.2.2]octane (13, Figure 4b), an analog of Ph-SMAP that has a bridgehead carbon atom instead of the Si atom.…”

Section: Electronic Properties Of Ph-smap (Dft Calculations)mentioning

confidence: 99%

Synthesis and properties of SMAPs 1-phospha-4-silabicyclo[2.2.2]octane derivatives

Ochida¹,

Sawamura²

2006

Arkivoc

View full text Add to dashboard Cite

Synthesis and properties of a new class of trialkylphosphine ligands SMAPs (1-phospha-4-silabicyclo[2.2.2]octane derivatives, named after silicon-constrained monodentate alkylphosphine) with Me 3 P-like steric demand around the phosphorus center are described. A new feature of this class of ligands is the presence of a site for functionalization at the backside of the P-lone pair, which is not the case for Me 3 P. The SMAP ligands contain phosphorus and silicon atoms at each bridgehead of the bicyclo[2.2.2]octane framework. The molecular constraint of the bicyclic framework makes the steric demand around the phosphorus center as small as that of Me 3 P and projects the P-lone pair and the Si-substituent (R) in diametrically opposite directions on the straight line defined by the two bridgehead atoms. SMAP derivatives bearing Si substituents with varied electronic natures are obtainable by transforming the parent compound 4-phenyl-phospha-4-silabicyclo[2.2.2]octane (Ph-SMAP) through Si-Ph bond cleavage, and they constitute a class of electronically tunable trialkylphosphines. DFT calculations indicated that the parent ligand Ph-SMAP is similar to Me 3 P in donor power and that the tunable range of the donor power overlaps those of (t-Bu) 3 P and RAr 2 P (R: alkyl, Ar: aryl).

show abstract

Quantifying the Electronic Effect of Substituted Phosphine Ligands via Molecular Electrostatic Potential

Cited by 169 publications

References 43 publications

A Priori Assessment of the Stereoelectronic Profile of Phosphines and Phosphites

A Priori Assessment of the Stereoelectronic Profile of Phosphines and Phosphites

Air-Stable, Compact, Caged Trialkylphosphines (SMAPs): Synthesis, Properties and Applications to Homogeneous and Heterogeneous Catalysis

Synthesis and properties of SMAPs 1-phospha-4-silabicyclo[2.2.2]octane derivatives

Contact Info

Product

Resources

About