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TY  - THES
AU  - Köhler, Manuela
TI  - Neue optisch aktive Phosphoniumsalze als Phasentransferkatalysatoren sowie die Verwendung der korrespondierenden Phosphane in der asymmetrischen Katalyse
CY  - Aachen
PB  - Publikationsserver der RWTH Aachen University
M1  - RWTH-CONV-123520
SP  - 208 S. : graph. Darst.
PY  - 2003
N1  - Prüfungsjahr: 2003. - Publikationsjahr: 2004
N1  - Aachen, Techn. Hochsch., Diss., 2003
AB  - Within this thesis, primary the application of optically active phosphoniumsalts in asymmetric phase transfer catalysis is described. Emphasis is placed on the Darzens-reaction of benzaldehyde and chloroacetophenone. First, achiral phosphoniumsalts were used under variation of the structure of the salt, temperature, reaction time and base. This was followed by the synthesis of polymerbound alkltriphenylphosphonium iodides , which were repeatedly used up to 18 times in a row as phase transfer catalysts. To obtain optically active phosphoniumsalts, first optically active phosphane precursors were quarternised with methyl iodine. Subsequently, phosphoniumsalts were derived from diphenylphosphino benzoic acid amides. The use of diphenylphosphino benzoic acid pentafluorophenol esters paved the way for the synthesis of a wide range of amides, which were obtained by conversion with diverse amines. It was found that sterically demanding substituents in alpha-position to the amide group led to the highest enantiomeric excesses, whereas the enantioselectivity dropped in case of substitution at the beta position. The highest enantiomeric excess was obtained with the methyl phosphonium iodine of ortho-diphenylphosphino benzoic acid coupled with adamantyl glycinole in 36
KW  - Darzens-Reaktion (SWD)
KW  - Asymmetrische Reaktion (SWD)
KW  - Phasentransfer-Katalyse (SWD)
KW  - Phosphoniumsalze (SWD)
KW  - Optisch aktive Verbindungen (SWD)
LB  - PUB:(DE-HGF)11
DO  - DOI:10.18154/RWTH-CONV-123520
UR  - https://publications.rwth-aachen.de/record/61907
ER  -