Phase transfer activation of fluorous analogs of Grubbs second-generation catalyst

Ring-opening metathesis polymerization

Robert Tuba, Rosenildo Corrêa Da Costa, Hassan S. Bazzi, John A. Gladysz

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Grubbs second-generation alkene metathesis catalyst and the fluorous analog (H 2IMes)((R f8(CH 2) 2) 3P)(Cl) 2Ru(=CHPh) (1; H 2IMes/R f8 = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene/(CF 2) 7CF 3) catalyze ring-opening metathesis polymerizations of norbornene at essentially identical rates (CDCl 3, RT). However, dramatic accelerations can be observed with 1 in the presence of the fluorous solvent perfluoro(methylcyclohexane) (PFMC). The fluorous phosphine (R f8(CH 2) 2) 3P must first dissociate from 1 to generate the 14-valence-electron intermediate that begins the catalytic cycle and should be scavenged by the PFMC phase (PFMC/toluene partition coefficient >99.7:<0.3). This would allow alkenes to more effectively compete for active catalyst. However, faster rates are seen only when 1 (partition coefficient 39.6:60.4) is added as a PFMC solution or a PFMC/CDCl 3 biphase mixture, as opposed to CDCl 3 solution, and possible additional contributing factors are analyzed. Analogous effects are observed with a 7-oxanorbornene-based N-butylsuccinimide. The molecular weights, polydispersities, glass transition temperatures, and cis/trans C=C linkage ratios of the polynorbornene produced under monophasic and biphasic conditions are compared and are usually similar.

Original languageEnglish
Pages (from-to)155-162
Number of pages8
JournalACS Catalysis
Volume2
Issue number1
DOIs
Publication statusPublished - 1 Jan 2012

Fingerprint

Ring opening polymerization
Olefins
Chemical activation
Catalysts
Polydispersity
phosphine
Toluene
Alkenes
Molecular weight
Electrons
perfluoromethylcyclohexane
Glass transition temperature

Keywords

  • biphase catalysis
  • fluorous
  • Grubbs' catalyst
  • phase transfer
  • polynorbornene
  • ROMP

ASJC Scopus subject areas

  • Catalysis

Cite this

Phase transfer activation of fluorous analogs of Grubbs second-generation catalyst : Ring-opening metathesis polymerization. / Tuba, Robert; Corrêa Da Costa, Rosenildo; Bazzi, Hassan S.; Gladysz, John A.

In: ACS Catalysis, Vol. 2, No. 1, 01.01.2012, p. 155-162.

Research output: Contribution to journalArticle

Tuba, Robert ; Corrêa Da Costa, Rosenildo ; Bazzi, Hassan S. ; Gladysz, John A. / Phase transfer activation of fluorous analogs of Grubbs second-generation catalyst : Ring-opening metathesis polymerization. In: ACS Catalysis. 2012 ; Vol. 2, No. 1. pp. 155-162.
@article{9a480cfae7e1438ebbb75c753b2fe89e,
title = "Phase transfer activation of fluorous analogs of Grubbs second-generation catalyst: Ring-opening metathesis polymerization",
abstract = "Grubbs second-generation alkene metathesis catalyst and the fluorous analog (H 2IMes)((R f8(CH 2) 2) 3P)(Cl) 2Ru(=CHPh) (1; H 2IMes/R f8 = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene/(CF 2) 7CF 3) catalyze ring-opening metathesis polymerizations of norbornene at essentially identical rates (CDCl 3, RT). However, dramatic accelerations can be observed with 1 in the presence of the fluorous solvent perfluoro(methylcyclohexane) (PFMC). The fluorous phosphine (R f8(CH 2) 2) 3P must first dissociate from 1 to generate the 14-valence-electron intermediate that begins the catalytic cycle and should be scavenged by the PFMC phase (PFMC/toluene partition coefficient >99.7:<0.3). This would allow alkenes to more effectively compete for active catalyst. However, faster rates are seen only when 1 (partition coefficient 39.6:60.4) is added as a PFMC solution or a PFMC/CDCl 3 biphase mixture, as opposed to CDCl 3 solution, and possible additional contributing factors are analyzed. Analogous effects are observed with a 7-oxanorbornene-based N-butylsuccinimide. The molecular weights, polydispersities, glass transition temperatures, and cis/trans C=C linkage ratios of the polynorbornene produced under monophasic and biphasic conditions are compared and are usually similar.",
keywords = "biphase catalysis, fluorous, Grubbs' catalyst, phase transfer, polynorbornene, ROMP",
author = "Robert Tuba and {Corr{\^e}a Da Costa}, Rosenildo and Bazzi, {Hassan S.} and Gladysz, {John A.}",
year = "2012",
month = "1",
day = "1",
doi = "10.1021/cs200487j",
language = "English",
volume = "2",
pages = "155--162",
journal = "ACS Catalysis",
issn = "2155-5435",
publisher = "American Chemical Society",
number = "1",

}

TY - JOUR

T1 - Phase transfer activation of fluorous analogs of Grubbs second-generation catalyst

T2 - Ring-opening metathesis polymerization

AU - Tuba, Robert

AU - Corrêa Da Costa, Rosenildo

AU - Bazzi, Hassan S.

AU - Gladysz, John A.

PY - 2012/1/1

Y1 - 2012/1/1

N2 - Grubbs second-generation alkene metathesis catalyst and the fluorous analog (H 2IMes)((R f8(CH 2) 2) 3P)(Cl) 2Ru(=CHPh) (1; H 2IMes/R f8 = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene/(CF 2) 7CF 3) catalyze ring-opening metathesis polymerizations of norbornene at essentially identical rates (CDCl 3, RT). However, dramatic accelerations can be observed with 1 in the presence of the fluorous solvent perfluoro(methylcyclohexane) (PFMC). The fluorous phosphine (R f8(CH 2) 2) 3P must first dissociate from 1 to generate the 14-valence-electron intermediate that begins the catalytic cycle and should be scavenged by the PFMC phase (PFMC/toluene partition coefficient >99.7:<0.3). This would allow alkenes to more effectively compete for active catalyst. However, faster rates are seen only when 1 (partition coefficient 39.6:60.4) is added as a PFMC solution or a PFMC/CDCl 3 biphase mixture, as opposed to CDCl 3 solution, and possible additional contributing factors are analyzed. Analogous effects are observed with a 7-oxanorbornene-based N-butylsuccinimide. The molecular weights, polydispersities, glass transition temperatures, and cis/trans C=C linkage ratios of the polynorbornene produced under monophasic and biphasic conditions are compared and are usually similar.

AB - Grubbs second-generation alkene metathesis catalyst and the fluorous analog (H 2IMes)((R f8(CH 2) 2) 3P)(Cl) 2Ru(=CHPh) (1; H 2IMes/R f8 = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene/(CF 2) 7CF 3) catalyze ring-opening metathesis polymerizations of norbornene at essentially identical rates (CDCl 3, RT). However, dramatic accelerations can be observed with 1 in the presence of the fluorous solvent perfluoro(methylcyclohexane) (PFMC). The fluorous phosphine (R f8(CH 2) 2) 3P must first dissociate from 1 to generate the 14-valence-electron intermediate that begins the catalytic cycle and should be scavenged by the PFMC phase (PFMC/toluene partition coefficient >99.7:<0.3). This would allow alkenes to more effectively compete for active catalyst. However, faster rates are seen only when 1 (partition coefficient 39.6:60.4) is added as a PFMC solution or a PFMC/CDCl 3 biphase mixture, as opposed to CDCl 3 solution, and possible additional contributing factors are analyzed. Analogous effects are observed with a 7-oxanorbornene-based N-butylsuccinimide. The molecular weights, polydispersities, glass transition temperatures, and cis/trans C=C linkage ratios of the polynorbornene produced under monophasic and biphasic conditions are compared and are usually similar.

KW - biphase catalysis

KW - fluorous

KW - Grubbs' catalyst

KW - phase transfer

KW - polynorbornene

KW - ROMP

UR - http://www.scopus.com/inward/record.url?scp=84855579356&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84855579356&partnerID=8YFLogxK

U2 - 10.1021/cs200487j

DO - 10.1021/cs200487j

M3 - Article

VL - 2

SP - 155

EP - 162

JO - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 1

ER -