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Organomolybdenum Complexes in Organic Synthesis- New methods for the Preparation of Cationic Diene Complexes and Applications to Synthesis

Bjurling, Emelie LU (2002)
Abstract
Indolyl substituted pyranyl- and cyclohexenyl molybdenum complexes were synthesised through stereoselective nucleophilic addition of indoles to the corresponding cationic 2H-pyran or cyclohexadiene molybdenum complex. Decomplexation of an allylic molybdneum complex by treatment with iodine gave 1-(4-iodo-2-cyclohexenyl)-1H-indole-3-carbonitrile in high regio-selectivity. A new method for preparation of eta-4-diene molybdneum complexes was developed based on in situ generation of carbenium ions effectuating hydride abstraction from neutral eta-3-allylic substrates. The presence of 1,1,1,3,3,3-hexafluoroisopropanol as a co-solvent was critical for successful hydride abstraction to occur with various di-or triarylmethyl halides or carbinols... (More)
Indolyl substituted pyranyl- and cyclohexenyl molybdenum complexes were synthesised through stereoselective nucleophilic addition of indoles to the corresponding cationic 2H-pyran or cyclohexadiene molybdenum complex. Decomplexation of an allylic molybdneum complex by treatment with iodine gave 1-(4-iodo-2-cyclohexenyl)-1H-indole-3-carbonitrile in high regio-selectivity. A new method for preparation of eta-4-diene molybdneum complexes was developed based on in situ generation of carbenium ions effectuating hydride abstraction from neutral eta-3-allylic substrates. The presence of 1,1,1,3,3,3-hexafluoroisopropanol as a co-solvent was critical for successful hydride abstraction to occur with various di-or triarylmethyl halides or carbinols as carbenium ion precursors. The first enantioselective hydride abstraction from an allylic molybdenum complex was performed, with an enantiomeric excess of up to 10%, utilising non-racemic 1-alkoxy-9-hydroxyxanthene derivatives as carbenium ion precursors. (Less)
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author
supervisor
opponent
  • Prof Moberg, Christina
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Organisk kemi, Organic chemistry, indoles, carbenium ions, hexafluoroisopropanol, hydride abstraction, molybdenum, cationic diene complexes
pages
106 pages
publisher
Organic Chemistry, Lund University
defense location
N/A
defense date
2001-01-26 10:15:00
ISBN
91-7874-172-6
language
English
LU publication?
yes
additional info
Article: Bjurling, E.; Johansson, M. H.; Andersson, C.-M.Synthesis of N-(2-Puranyl)-and N- Cyclohexenylindole Derivatives via StereoselectiveAddition of Indole Nucleophiles to Organomolybdneum Complexes.Organometallics, 1999, 18, 5606-5613. Article: Bjurling, E.; Andersson, C.-M.An alternative Procedure for Preparing Cationic eta-4-Diene- Molybdenum Complexesfrom the Corresponding Allylic Precursors.Tetrahedron Lett. 1999, 40, 1981. Article: Bjurling, E.; Björkman, A.; Andersson, C.-M.Preparation of Cationic Cyclopentadienyl Diene Molybdneum Complexes throughHydride Abstraction Effected by Di- or Triarylmethyl Halides in the Presence ofHexafluoro-2-propanol.Organometallics, 2001, 20, 990-994. Article: Bjurling E.; Berg, U.; Andersson, C.-M.Hydride Abstraction from eta-3-Allylic Molybdenum Complexes Exploring Various DiarylCarbenium Ion Precursors. A Study towards Enantioselective Hydride Abstraction.Submitted for publication. 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
09b840c9-cc60-465c-8722-790f8fb0a84a (old id 464266)
date added to LUP
2016-04-04 11:24:07
date last changed
2018-11-21 21:04:37
@phdthesis{09b840c9-cc60-465c-8722-790f8fb0a84a,
  abstract     = {Indolyl substituted pyranyl- and cyclohexenyl molybdenum complexes were synthesised through stereoselective nucleophilic addition of indoles to the corresponding cationic 2H-pyran or cyclohexadiene molybdenum complex. Decomplexation of an allylic molybdneum complex by treatment with iodine gave 1-(4-iodo-2-cyclohexenyl)-1H-indole-3-carbonitrile in high regio-selectivity. A new method for preparation of eta-4-diene molybdneum complexes was developed based on in situ generation of carbenium ions effectuating hydride abstraction from neutral eta-3-allylic substrates. The presence of 1,1,1,3,3,3-hexafluoroisopropanol as a co-solvent was critical for successful hydride abstraction to occur with various di-or triarylmethyl halides or carbinols as carbenium ion precursors. The first enantioselective hydride abstraction from an allylic molybdenum complex was performed, with an enantiomeric excess of up to 10%, utilising non-racemic 1-alkoxy-9-hydroxyxanthene derivatives as carbenium ion precursors.},
  author       = {Bjurling, Emelie},
  isbn         = {91-7874-172-6},
  language     = {eng},
  publisher    = {Organic Chemistry, Lund University},
  school       = {Lund University},
  title        = {Organomolybdenum Complexes in Organic Synthesis- New methods for the Preparation of Cationic Diene Complexes and Applications to Synthesis},
  year         = {2002},
}