Synthetic and Mechanistic Studies of Organometallic Compounds to Activate NO2 and Organic Compounds.

Master's Thesis

Abstract

Pt(IV) complexes of L2Pt(CH3)3NO2 (L2 = 1,2- bis(diphenylphosphino)ethane (dppe) or 1,2- bis(diphenylphosphino)benzene (dppbz)) were synthesized and characterized. On thermolysis in relatively nonpolar solvents, benzene-d6 and THF-d8, the complexes undergo competitive C-C (ethane), C-N (nitromethane), and C-O (methyl nitrite) reductive elimination. Heating in acetone-d6 the C-C reductive elimination is favored in polar solvent. With the addition of acid scavenger, PVP, C-N and C-O reductive elimination are observed in high yield in benzene-d6 and THF-d8. Mechanistic studies determined that the reactions are initiated by dissociation of NO2- , leaving a cationic five coordinate Pt(IV) intermediate. The C-N and C-O products are then formed by an SN2 attack on a methyl by the dissociated NO2-. C-C reductive elimination is in competition with nucleophilic attack and forms solely from the cationic intermediate. The complex (E)-2,4-di-tert-butyl-6-((3,5-di-tert-butyl-2 hydroxybenzylidene)amino)phenol bismuth phenyl ((ONCO)BiPh) was successfully synthesized and characterized. Attempts to synthesize the Bi(V) complex, (ONCO)BiPh(OAc)2, proved to be difficult. Under oxidizing conditions the ONCO ligand will dissociate from the bismuth and oxidize to form 5,7-di-tert-butyl-2-(2-hydroxy-3,5-di-tert-butylphenyl)benzoxazole. Utilizing tetradentate ligands like 6,6’-(piperazine-1,4-diylbis(methylene))bis(2,4-di-tert-butylphenol) or 6,6’-((1,4-diazepane-1,4-diyl)bis(methylene))bis(2-(tert-butyl)-4-methoxyphenol) could bypass the oxidation of the ligand due to the tetradentate ligands being bound more tightly then ONCOH2. Ipso nitration of boronic acids and boronic acid pinacol esters can be achieved using NO2 (g). Boronic acids and electron rich boronic pinacol esters typically do not need a catalyst to form the nitro-deboronation product, but the less reactive boronic acid pinacol esters and electron poor boronic acids seem to need a catalyst to form the desired product. Several transition metal compounds showed catalytic activity in reactions, however the most suitable catalyst was found to be IrPy3Cl3. Under these conditions good to excellent yields can be obtained.

Attributes

Attribute NameValues
URN
  • etd-07182014-123550

Author Arnold Bertron Kidd IV
Advisor Seth N. Brown
Contributor Vlad M. Iluc, Committee Member
Contributor Seth N. Brown, Committee Chair
Contributor A. Graham Lappin, Committee Member
Degree Level Master's Thesis
Degree Discipline Chemistry and Biochemistry
Degree Name MS
Defense Date
  • 2014-07-17

Submission Date 2014-07-18
Country
  • United States of America

Subject
  • Organometallic chemsitry

  • Organic chemistry

  • Inorganic chemistry

Publisher
  • University of Notre Dame

Language
  • English

Record Visibility Public
Embargo Release Date
  • 2015-10-15

Content License
  • All rights reserved

Departments and Units

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