Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation

Craig M. Forsyth, Steven P. Nolan, Charlotte L. Stern, Tobin J Marks, Arnold L. Rheingold

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

This contribution addresses, using the non-redox-active ion La3+, the constraints under which lanthanide M-C≡CR functionalities undergo facile coupling to yield binuclear M2(μ-RC4R) complexes. The reaction of Cp′2LaCHTMS2 (Cp′ = η5-Me5C5) with PhCCH at room temperature yields the coupled product (Cp′2La)2(μ-PhC4Ph) (monoclinic space group C2/m, a = 15.600(2) Å, b = 14.318(2) Å, c = 15.368(2) Å, β = 114.17(1)°, Z = 2, R = 0.050, Rw = 0.063) plus CH2TMS2. Reaction of Cp′2LaCHTMS2 with t-BuCCH at 0°C, yields the uncoupled dimer (Cp′2LaC2-t-Bu)2 (plus CH2TMS2), which, in toluene solution at 50 and 60°C, undergoes clean unimolecular conversion to the coupled dimer (Cp′2La)2(μ-BuC4-t-Bu) (monoclinic space group P21/n, a = 11.232(2) Å, b = 14.199(3) Å, c = 15.309(4) Å, β = 103.35(2)°, Z = 2, R = 0.027, Rw = 0.034). These results argue that excursions in formal metal oxidation state (+3 ⇌ +2) are not important along the reaction coordinate, that acetylene aryl substituents are not necessary for the coupling process to occur, and that the immediate kinetic precursor to the coupled product is an uncoupled dimer.

Original languageEnglish
Pages (from-to)3618-3623
Number of pages6
JournalOrganometallics
Volume12
Issue number9
Publication statusPublished - 1993

Fingerprint

Alkynes
alkynes
Dimers
Metals
dimers
metals
Acetylene
Lanthanoid Series Elements
Toluene
products
acetylene
toluene
Ions
Oxidation
oxidation
Kinetics
kinetics
room temperature
ions
Temperature

ASJC Scopus subject areas

  • Inorganic Chemistry
  • Organic Chemistry

Cite this

Forsyth, C. M., Nolan, S. P., Stern, C. L., Marks, T. J., & Rheingold, A. L. (1993). Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation. Organometallics, 12(9), 3618-3623.

Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation. / Forsyth, Craig M.; Nolan, Steven P.; Stern, Charlotte L.; Marks, Tobin J; Rheingold, Arnold L.

In: Organometallics, Vol. 12, No. 9, 1993, p. 3618-3623.

Research output: Contribution to journalArticle

Forsyth, CM, Nolan, SP, Stern, CL, Marks, TJ & Rheingold, AL 1993, 'Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation', Organometallics, vol. 12, no. 9, pp. 3618-3623.
Forsyth, Craig M. ; Nolan, Steven P. ; Stern, Charlotte L. ; Marks, Tobin J ; Rheingold, Arnold L. / Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation. In: Organometallics. 1993 ; Vol. 12, No. 9. pp. 3618-3623.
@article{59753cd01794470db4db7d31b33a728b,
title = "Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation",
abstract = "This contribution addresses, using the non-redox-active ion La3+, the constraints under which lanthanide M-C≡CR functionalities undergo facile coupling to yield binuclear M2(μ-RC4R) complexes. The reaction of Cp′2LaCHTMS2 (Cp′ = η5-Me5C5) with PhCCH at room temperature yields the coupled product (Cp′2La)2(μ-PhC4Ph) (monoclinic space group C2/m, a = 15.600(2) {\AA}, b = 14.318(2) {\AA}, c = 15.368(2) {\AA}, β = 114.17(1)°, Z = 2, R = 0.050, Rw = 0.063) plus CH2TMS2. Reaction of Cp′2LaCHTMS2 with t-BuCCH at 0°C, yields the uncoupled dimer (Cp′2LaC2-t-Bu)2 (plus CH2TMS2), which, in toluene solution at 50 and 60°C, undergoes clean unimolecular conversion to the coupled dimer (Cp′2La)2(μ-BuC4-t-Bu) (monoclinic space group P21/n, a = 11.232(2) {\AA}, b = 14.199(3) {\AA}, c = 15.309(4) {\AA}, β = 103.35(2)°, Z = 2, R = 0.027, Rw = 0.034). These results argue that excursions in formal metal oxidation state (+3 ⇌ +2) are not important along the reaction coordinate, that acetylene aryl substituents are not necessary for the coupling process to occur, and that the immediate kinetic precursor to the coupled product is an uncoupled dimer.",
author = "Forsyth, {Craig M.} and Nolan, {Steven P.} and Stern, {Charlotte L.} and Marks, {Tobin J} and Rheingold, {Arnold L.}",
year = "1993",
language = "English",
volume = "12",
pages = "3618--3623",
journal = "Organometallics",
issn = "0276-7333",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Alkyne coupling reactions mediated by organolanthanides. Probing the mechanism by metal and alkyne variation

AU - Forsyth, Craig M.

AU - Nolan, Steven P.

AU - Stern, Charlotte L.

AU - Marks, Tobin J

AU - Rheingold, Arnold L.

PY - 1993

Y1 - 1993

N2 - This contribution addresses, using the non-redox-active ion La3+, the constraints under which lanthanide M-C≡CR functionalities undergo facile coupling to yield binuclear M2(μ-RC4R) complexes. The reaction of Cp′2LaCHTMS2 (Cp′ = η5-Me5C5) with PhCCH at room temperature yields the coupled product (Cp′2La)2(μ-PhC4Ph) (monoclinic space group C2/m, a = 15.600(2) Å, b = 14.318(2) Å, c = 15.368(2) Å, β = 114.17(1)°, Z = 2, R = 0.050, Rw = 0.063) plus CH2TMS2. Reaction of Cp′2LaCHTMS2 with t-BuCCH at 0°C, yields the uncoupled dimer (Cp′2LaC2-t-Bu)2 (plus CH2TMS2), which, in toluene solution at 50 and 60°C, undergoes clean unimolecular conversion to the coupled dimer (Cp′2La)2(μ-BuC4-t-Bu) (monoclinic space group P21/n, a = 11.232(2) Å, b = 14.199(3) Å, c = 15.309(4) Å, β = 103.35(2)°, Z = 2, R = 0.027, Rw = 0.034). These results argue that excursions in formal metal oxidation state (+3 ⇌ +2) are not important along the reaction coordinate, that acetylene aryl substituents are not necessary for the coupling process to occur, and that the immediate kinetic precursor to the coupled product is an uncoupled dimer.

AB - This contribution addresses, using the non-redox-active ion La3+, the constraints under which lanthanide M-C≡CR functionalities undergo facile coupling to yield binuclear M2(μ-RC4R) complexes. The reaction of Cp′2LaCHTMS2 (Cp′ = η5-Me5C5) with PhCCH at room temperature yields the coupled product (Cp′2La)2(μ-PhC4Ph) (monoclinic space group C2/m, a = 15.600(2) Å, b = 14.318(2) Å, c = 15.368(2) Å, β = 114.17(1)°, Z = 2, R = 0.050, Rw = 0.063) plus CH2TMS2. Reaction of Cp′2LaCHTMS2 with t-BuCCH at 0°C, yields the uncoupled dimer (Cp′2LaC2-t-Bu)2 (plus CH2TMS2), which, in toluene solution at 50 and 60°C, undergoes clean unimolecular conversion to the coupled dimer (Cp′2La)2(μ-BuC4-t-Bu) (monoclinic space group P21/n, a = 11.232(2) Å, b = 14.199(3) Å, c = 15.309(4) Å, β = 103.35(2)°, Z = 2, R = 0.027, Rw = 0.034). These results argue that excursions in formal metal oxidation state (+3 ⇌ +2) are not important along the reaction coordinate, that acetylene aryl substituents are not necessary for the coupling process to occur, and that the immediate kinetic precursor to the coupled product is an uncoupled dimer.

UR - http://www.scopus.com/inward/record.url?scp=0000440816&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000440816&partnerID=8YFLogxK

M3 - Article

VL - 12

SP - 3618

EP - 3623

JO - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 9

ER -