Coordination chemistry of late transition metals with PCP ligands. Synthesis, catalysis and mechanism

Olsson, Daniel

Coordination chemistry of late transition metals with PCP ligands. Synthesis, catalysis and mechanism

Mark

Olsson, Daniel ^LU (2007)

Abstract: Abstract

The work presented in this thesis discusses synthesis of PCP-complexes and utilisations of such organometallic compounds in catalysis. The complexes, obtained by intramolecular Csp3-H activation, are based on the metals palladium, platinum and iridium. The synthesis of PCP-ligands include new and improved preparative routes to the previously known cis-1,3-bis-(di-iso-propylphosphinito)cyclohexane (6), cis-1,3-bis[(di-tert-butylphosphino)cyclohexane (1) and the new compound cis-1,3-Bis-(di-tert-butylphosphinito)cyclohexane (5).

With dichloro(1,5-cyclooctadiene)platinum(II) the phosphinite ligands were reluctant to Csp3-H activate and gave... (More); Abstract

The work presented in this thesis discusses synthesis of PCP-complexes and utilisations of such organometallic compounds in catalysis. The complexes, obtained by intramolecular Csp3-H activation, are based on the metals palladium, platinum and iridium. The synthesis of PCP-ligands include new and improved preparative routes to the previously known cis-1,3-bis-(di-iso-propylphosphinito)cyclohexane (6), cis-1,3-bis[(di-tert-butylphosphino)cyclohexane (1) and the new compound cis-1,3-Bis-(di-tert-butylphosphinito)cyclohexane (5).

With dichloro(1,5-cyclooctadiene)platinum(II) the phosphinite ligands were reluctant to Csp3-H activate and gave cis-[PtCl2{cis-1,3-bis-(di-iso-propylphosphinito)}-cyclohexane] (7) along with the di-nuclear trans-[PtCl2{cis-1,3-Bis-(di-tert-butyl-phosphinito)-cyclohexane}]2 complex. The platinum precursor successfully produced the PCsp3P-complex cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]-chloroplatinum(II) (8) with the phosphine ligand 1. With the dinuclear precursor bis(1,5-cyclooctadiene)diiridium(I) dichloride the phosphine ligand 1 gave the Csp3-H activated hydrido complex cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]chlorhydridoiridium(III) (9).Substitution on the previously known cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]trifluoroacetopalladium(II) (2) produced cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]bromide-palladium(II) (10) and cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]phenylpalladium(II) (11) with NaBr and PhLi, respectively.

The catalytic properties of the aromatic PCP complex {2,6-bis[(diphenyl-phosphino)methyl]-benzene}-(trifluoroacetato)palladium(II) was investigated in the Stille reaction and proved to be an excellent catalyst for the C?C cross-coupling between trimethyl phenyl stannane and aryl bromides using a very low catalyst loading at elevated temperature. Mercury poisoning test and a kinetic investigation of the catalytic reaction suggests a colloidal palladium catalyst formed from the PCP Pd(II) pre-catalyst. The aliphatic complex 2 was investigated as a precatalyst for the Suzuki reaction of aryl halides with phenylboronic acid in the absence or presence of mercury to give the product in modest to reasonably good yields. Stepwise reactions, monitored by 31P- and 1H-NMR spectroscopy concluded that complex 2 preferred activated boronic acid over aryl halide in the first reaction step to yield the phenyl complex 11. The phenyl complex thereafter generated the corresponding bromo complex 10 and the Suzuki cross coupling product upon addition of aryl halide. The investigation proves that palladium PCP complexes can mediate cross-coupling reactions in an elevated oxidation state. (Less)
Abstract (Swedish): Popular Abstract in Swedish

Eftersom allt i och runt oss består av kemikalier är det av högsta vikt att vi förstår hur dessa reagerar med varandra. Katalytiska omvandlingar är kemiska reaktioner där en katalysator underhåller en reaktion utan att själv förbrukas. Inom metallorganisk kemi är tillverkning och förstålelsen av hur komplex med övergångsmetaller kan användas vi katalys mycket viktig. Kol-väte bindningen är mycket reaktions trög och därmed mycket stabil. Om man lyckas bryta bindningen och ersätta vätet med en övergångsmetall vid så kallad C-H aktivering erhålls ofta mycket stabila metallorganiska komplex som öppnar nya möjligheter vid katalytiska reaktioner där hög temperatur är av vikt.

... (More); Popular Abstract in Swedish

Eftersom allt i och runt oss består av kemikalier är det av högsta vikt att vi förstår hur dessa reagerar med varandra. Katalytiska omvandlingar är kemiska reaktioner där en katalysator underhåller en reaktion utan att själv förbrukas. Inom metallorganisk kemi är tillverkning och förstålelsen av hur komplex med övergångsmetaller kan användas vi katalys mycket viktig. Kol-väte bindningen är mycket reaktions trög och därmed mycket stabil. Om man lyckas bryta bindningen och ersätta vätet med en övergångsmetall vid så kallad C-H aktivering erhålls ofta mycket stabila metallorganiska komplex som öppnar nya möjligheter vid katalytiska reaktioner där hög temperatur är av vikt.

Föreliggande avhandling sammanfattar studier av tillverkning av C-H aktiverade komplex med övergångsmetaller samt undersökningar av katalytiska kol-kol kopplingsreaktioner i fem bilagda vetenskapliga artiklar. De metallorganiska komplexen består av en difosfinligand (en så kallad PCP-ligand) innehållande cyklohexan och palladium, platina, och iridium som övergångsmetallerna. Själva C-H aktiveringsprocessen sker vid hög temperatur för både platina och iridium medan med palladium sker reaktionen vid rumstemperatur och de erhållna komplexen är mycket termiskt stabila.

De båda korskopplingsreaktioner, kallade Heck och Suzuki, som undersöktes förklaras med två olika mekanismer. För Heck-reaktionen används en förklaringsmodell där den palladium innehållande katalysatorn (PCP-komplexet) läcker mycket små mängder katalytisk aktivt palladium(0). Detta visas med förgiftningsförsök där kvicksilver används. Aktiviteten för det undersökta komplexet som användes i Suzuki reaktionen har en annan förklaring. I det här fallet påverkas reaktionen mycket lite av kvicksilver och därför anses komplexet underhålla reaktionen i intakt form. Dessutom kan kontrollexperiment utförda med NMR spektroskopi följa katalysatorns uppförande under Suzuki reaktionen varpå de olika katalytiska intermediaten påvisades. Avhandlingen visar alltså att samma typ av metallorganiska komplex kan underhålla katalytiska reaktioner via olika reaktionsvägar. (Less)

Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/598976

author

Olsson, Daniel ^LU

supervisor

Ola Wendt ^LU

opponent

Professor Norrby, Per-Ola, Inst för kemi,Göteborgs universitet, Kemigården 4, 412 96 Göteborg

organization

Centre for Analysis and Synthesis

publishing date

2007

type

Thesis

publication status

published

subject

Organic Chemistry

keywords

Organisk kemi, Organometallic chemistry, Metallorganisk kemi, Organic chemistry, Oorganisk kemi, Inorganic chemistry, Suzuki reaction, Stille reaction, catalysis, cyclometalation, C-H activation, PCP complex, POCOP ligand, PCP ligand, iridium, palladium, platinum

pages

144 pages

publisher

Organisk kemi, Kemiska institutionen, Box 188, 221 00 Lund

defense location

Sal F, Kemicentrum

defense date

2007-10-18 10:15:00

ISBN

978-91-7422-173-2

language

English

LU publication?

yes

additional info

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Organic chemistry (S/LTH) (011001240)

id

f874fe53-73d2-4ce5-8566-61c855b84ecc (old id 598976)

date added to LUP

2016-04-04 12:20:52

date last changed

2018-11-21 21:10:26

@phdthesis{f874fe53-73d2-4ce5-8566-61c855b84ecc,
  abstract     = {{Abstract<br/><br>
<br/><br>
The work presented in this thesis discusses synthesis of PCP-complexes and utilisations of such organometallic compounds in catalysis. The complexes, obtained by intramolecular Csp3-H activation, are based on the metals palladium, platinum and iridium. The synthesis of PCP-ligands include new and improved preparative routes to the previously known cis-1,3-bis-(di-iso-propylphosphinito)cyclohexane (6), cis-1,3-bis[(di-tert-butylphosphino)cyclohexane (1) and the new compound cis-1,3-Bis-(di-tert-butylphosphinito)cyclohexane (5).<br/><br>
<br/><br>
With dichloro(1,5-cyclooctadiene)platinum(II) the phosphinite ligands were reluctant to Csp3-H activate and gave cis-[PtCl2{cis-1,3-bis-(di-iso-propylphosphinito)}-cyclohexane] (7) along with the di-nuclear trans-[PtCl2{cis-1,3-Bis-(di-tert-butyl-phosphinito)-cyclohexane}]2 complex. The platinum precursor successfully produced the PCsp3P-complex cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]-chloroplatinum(II) (8) with the phosphine ligand 1. With the dinuclear precursor bis(1,5-cyclooctadiene)diiridium(I) dichloride the phosphine ligand 1 gave the Csp3-H activated hydrido complex cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]chlorhydridoiridium(III) (9).Substitution on the previously known cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]trifluoroacetopalladium(II) (2) produced cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]bromide-palladium(II) (10) and cis-[2,6-bis(di-tert-butylphosphinomethyl)cyclohexyl-?3P,C1,P?]phenylpalladium(II) (11) with NaBr and PhLi, respectively.<br/><br>
<br/><br>
The catalytic properties of the aromatic PCP complex {2,6-bis[(diphenyl-phosphino)methyl]-benzene}-(trifluoroacetato)palladium(II) was investigated in the Stille reaction and proved to be an excellent catalyst for the C?C cross-coupling between trimethyl phenyl stannane and aryl bromides using a very low catalyst loading at elevated temperature. Mercury poisoning test and a kinetic investigation of the catalytic reaction suggests a colloidal palladium catalyst formed from the PCP Pd(II) pre-catalyst. The aliphatic complex 2 was investigated as a precatalyst for the Suzuki reaction of aryl halides with phenylboronic acid in the absence or presence of mercury to give the product in modest to reasonably good yields. Stepwise reactions, monitored by 31P- and 1H-NMR spectroscopy concluded that complex 2 preferred activated boronic acid over aryl halide in the first reaction step to yield the phenyl complex 11. The phenyl complex thereafter generated the corresponding bromo complex 10 and the Suzuki cross coupling product upon addition of aryl halide. The investigation proves that palladium PCP complexes can mediate cross-coupling reactions in an elevated oxidation state.}},
  author       = {{Olsson, Daniel}},
  isbn         = {{978-91-7422-173-2}},
  keywords     = {{Organisk kemi; Organometallic chemistry; Metallorganisk kemi; Organic chemistry; Oorganisk kemi; Inorganic chemistry; Suzuki reaction; Stille reaction; catalysis; cyclometalation; C-H activation; PCP complex; POCOP ligand; PCP ligand; iridium; palladium; platinum}},
  language     = {{eng}},
  publisher    = {{Organisk kemi, Kemiska institutionen, Box 188, 221 00 Lund}},
  school       = {{Lund University}},
  title        = {{Coordination chemistry of late transition metals with PCP ligands. Synthesis, catalysis and mechanism}},
  year         = {{2007}},
}

Lund University Publications

LUND UNIVERSITY LIBRARIES

Coordination chemistry of late transition metals with PCP ligands. Synthesis, catalysis and mechanism