h1

TY  - THES
AU  - Philipps, Arne R.
TI  - Katalytische asymmetrische Synthesen von Cyclohexencarbaldehyden, Indanen und 4H-Chromenen
PB  - RWTH Aachen University
VL  - Dissertation
CY  - Aachen
M1  - RWTH-2017-03158
SP  - 1 Online-Ressource (II, 142 Seiten) : Illustrationen, Diagramme
PY  - 2017
N1  - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University
N1  - Dissertation, RWTH Aachen University, 2017
AB  - In this thesis, three different reaction sequences were developed, enabling the catalytic asymmetric synthesis of carbo- and heterocycles. In addition to one method for the organocatalytic synthesis of cyclohexencarbaldehydes bearing three contiguous stereocenters, two methods concerning the combination of organo- and metal catalysis were investigated. In the first project, the asymmetric synthesis of cyclohexencarbaldehydes via organocatalysis with the secondary amine diphenyl prolinol-TMS-ether was realized. In this cascade reaction, consisting of a vinylogous Friedel-Crafts/Michael/Michael/Aldol condensation sequence, several nucleophilic bis(anilin)alkenes and nitro olefins with aromatic and heteroaromatic substituents could be used. The products were obtained in good yields with excellent enantiomeric excesses. The diastereomeric ratios ranged from 9:1 to 20:1. In the second project a Michael/Conia-ene sequence was developed, allowing the synthesis of methyleneindanes and methylindenes. As starting materials, 1,3-diketones or malonates and 2-ethinyl nitrostyrenes were used. The Michael addition was catalyzed by a squaramide bearing a chiral scaffold derived from quinine, while the Conia-ene reaction was catalyzed by Indium(III)-triflate. The products were obtained in yields of up to 99
LB  - PUB:(DE-HGF)11
DO  - DOI:10.18154/RWTH-2017-03158
UR  - https://publications.rwth-aachen.de/record/687139
ER  -