Oxidative additions of amides to an iridium(I) metal center
Carboxylic amides will add oxidatively via N-H activation to the complex [(COD)Ir(PMe3h]CI (where COD 1,5-cyclooctadiene) in organic solvents at 80°C to form stable iridium hydrides with the hydride arranged cis to nitrogen and trans to chloride. Acetamide will add to form the complex mer-(MeC(O)...
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ndltd-VTETD-oai-vtechworks.lib.vt.edu-10919-434582021-05-26T05:48:32Z Oxidative additions of amides to an iridium(I) metal center Clark, Robert D. Chemistry Merola, Joseph S. Hanson, Brian E. Anderson, Mark R. amides LD5655.V855 1995.C537 Carboxylic amides will add oxidatively via N-H activation to the complex [(COD)Ir(PMe3h]CI (where COD 1,5-cyclooctadiene) in organic solvents at 80°C to form stable iridium hydrides with the hydride arranged cis to nitrogen and trans to chloride. Acetamide will add to form the complex mer-(MeC(O)HN)IrH(PMe3)3CI which is isolable as a sticky yellow solid and soluble in all common solvents. The reaction with benzamide in toluene at 80°C produces the complex mer( PhC(O)HN)IrH(PMe3)3CI which is stabilized by a hydrogen bonding interaction with one equivalent of excess benzamide. All attempts to isolate the organometallic failed as the organometallic degraded quickly in the absence of amide. FTIR experiments indicated a significant hydrogen bonding interaction between the benzamide and mer(PhC(O)HN)IrH(PMe3)3Cl. NMR scale reactions with acrylamide and benzanalide showed that oxidative N-H addition could occur despite the presence of an unsaturate or an N-substituent. The attempts to form the thioamide analogues of the acetamide and benzamide complexes failed to produce stable iridium hydrides. Thioacetamide will add to [(COD)Ir(PMe3)3]CI in chloroform or methylene chloride; however~ any hydrido species which formed subsequently reacted with the solvent to produce fac( MeC(S)HN)Ir(PMe3)3Ch. All attempts at adding thiobenzamide to [(COD)Ir(PMe3)3)CI produced an uncharacterizable mixture of products. The reactivity ofmer-(PhC(O)HN)IrH(PMe3)3CI was probed with regard to its potential for catalytic amination. Reaction with TIPF6 in methylene chloride showed evidence for the formation of the bidentate amide mer-[(PhC(O)HN)IrH(PMe3)3]CI where the amide is chelated through the nitrogen and the oxygen; however, the species was not stable and could not be isolated. Refluxing mer-(PhC(O)HN)IrH(PMe3)3CI in water produces a rearrangement to form another isomer of mer( PhC(O)HN)IrH(PMe3)3CI in which the hydride is trans to nitrogen and cis to chloride. Reactions with unsaturates in benzene, chloroform, and water at elevated temperatures produced evidence for the formation of insertion products. The reaction of mer( PhC(O)HN)IrH(PMe3)3CI with t-butyl acetylene in water shows evidence for the formation of an amidated elimination product, though it was not shown to be catalytic. Master of Science 2014-03-14T21:39:12Z 2014-03-14T21:39:12Z 1995-08-27 2009-06-23 2009-06-23 2009-06-23 Thesis Text etd-06232009-063527 http://hdl.handle.net/10919/43458 http://scholar.lib.vt.edu/theses/available/etd-06232009-063527/ en OCLC# 34185569 LD5655.V855_1995.C537.pdf In Copyright http://rightsstatements.org/vocab/InC/1.0/ viii, 69 leaves BTD application/pdf application/pdf Virginia Tech |
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amides LD5655.V855 1995.C537 |
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amides LD5655.V855 1995.C537 Clark, Robert D. Oxidative additions of amides to an iridium(I) metal center |
description |
Carboxylic amides will add oxidatively via N-H activation to the complex
[(COD)Ir(PMe3h]CI (where COD 1,5-cyclooctadiene) in organic solvents at 80°C to
form stable iridium hydrides with the hydride arranged cis to nitrogen and trans to
chloride. Acetamide will add to form the complex mer-(MeC(O)HN)IrH(PMe3)3CI
which is isolable as a sticky yellow solid and soluble in all common solvents. The
reaction with benzamide in toluene at 80°C produces the complex mer(
PhC(O)HN)IrH(PMe3)3CI which is stabilized by a hydrogen bonding interaction with
one equivalent of excess benzamide. All attempts to isolate the organometallic failed as
the organometallic degraded quickly in the absence of amide. FTIR experiments
indicated a significant hydrogen bonding interaction between the benzamide and mer(PhC(O)HN)IrH(PMe3)3Cl. NMR scale reactions with acrylamide and benzanalide
showed that oxidative N-H addition could occur despite the presence of an unsaturate or an N-substituent.
The attempts to form the thioamide analogues of the acetamide and benzamide
complexes failed to produce stable iridium hydrides. Thioacetamide will add to
[(COD)Ir(PMe3)3]CI in chloroform or methylene chloride; however~ any hydrido species
which formed subsequently reacted with the solvent to produce fac(
MeC(S)HN)Ir(PMe3)3Ch. All attempts at adding thiobenzamide to [(COD)Ir(PMe3)3)CI
produced an uncharacterizable mixture of products.
The reactivity ofmer-(PhC(O)HN)IrH(PMe3)3CI was probed with regard to its
potential for catalytic amination. Reaction with TIPF6 in methylene chloride showed
evidence for the formation of the bidentate amide mer-[(PhC(O)HN)IrH(PMe3)3]CI
where the amide is chelated through the nitrogen and the oxygen; however, the species
was not stable and could not be isolated. Refluxing mer-(PhC(O)HN)IrH(PMe3)3CI in
water produces a rearrangement to form another isomer of mer(
PhC(O)HN)IrH(PMe3)3CI in which the hydride is trans to nitrogen and cis to chloride.
Reactions with unsaturates in benzene, chloroform, and water at elevated temperatures
produced evidence for the formation of insertion products. The reaction of mer(
PhC(O)HN)IrH(PMe3)3CI with t-butyl acetylene in water shows evidence for the
formation of an amidated elimination product, though it was not shown to be catalytic. === Master of Science |
author2 |
Chemistry |
author_facet |
Chemistry Clark, Robert D. |
author |
Clark, Robert D. |
author_sort |
Clark, Robert D. |
title |
Oxidative additions of amides to an iridium(I) metal center |
title_short |
Oxidative additions of amides to an iridium(I) metal center |
title_full |
Oxidative additions of amides to an iridium(I) metal center |
title_fullStr |
Oxidative additions of amides to an iridium(I) metal center |
title_full_unstemmed |
Oxidative additions of amides to an iridium(I) metal center |
title_sort |
oxidative additions of amides to an iridium(i) metal center |
publisher |
Virginia Tech |
publishDate |
2014 |
url |
http://hdl.handle.net/10919/43458 http://scholar.lib.vt.edu/theses/available/etd-06232009-063527/ |
work_keys_str_mv |
AT clarkrobertd oxidativeadditionsofamidestoaniridiumimetalcenter |
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