Universität zu Köln

Kleczka, Margarethe, But, Diana, Dylong, Dominik, Fendinger, Carolina, Marmann, Verena, Wartke, Christian and Griesbeck, Axel G. ORCID: 0000-0002-6546-3482 (2018). Two Useful Directing Modes in Singlet Oxygen Reactivity: Electrostatic Effects in the Ene Reaction with Allylic Alcoholates and a Chemoselectivity Change with alpha-Alkoxy Michael Esters. ChemPhotoChem, 2 (11). S. 964 - 976. WEINHEIM: WILEY-V C H VERLAG GMBH. ISSN 2367-0932

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Abstract

The singlet oxygen reaction with trisubstituted E-allylic alcohols resulted in the unselective formation of regioisomeric secondary and tertiary allylic hydroperoxides. Increasing the steric demand at the allylic hydroxymethyl group leads to a moderate large-group effect that can be strongly enhanced by deprotonation of a dimethylated allylic alcohol and even more pronounced by cation complexation. The presence of alkoxide groups did additionally alter the diastereoselectivity of the singlet oxygen ene reactions with chiral allylic alcohols. The molecular combination of Michael ester and enol ether in alpha-alkoxy ester substrates made possible the design of chemoselective substrates for singlet oxygen ene versus [2+2] cycloaddition, e. g. a 3,3-dimethylated Michael ester as a selective substrate for the ene reaction and an adamantyl analogue as a selective 2+2 substrate. The Z/E-monomethylated substrates as probes for cis regioselectivity revealed that there is no site preference for Z-alkoxy hydrogen transfer on the way to the corresponding ene product.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Kleczka, Margarethe UNSPECIFIED UNSPECIFIED UNSPECIFIED But, Diana UNSPECIFIED UNSPECIFIED UNSPECIFIED Dylong, Dominik UNSPECIFIED UNSPECIFIED UNSPECIFIED Fendinger, Carolina UNSPECIFIED UNSPECIFIED UNSPECIFIED Marmann, Verena UNSPECIFIED UNSPECIFIED UNSPECIFIED Wartke, Christian UNSPECIFIED UNSPECIFIED UNSPECIFIED Griesbeck, Axel G. UNSPECIFIED orcid.org/0000-0002-6546-3482 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-167775
DOI:	10.1002/cptc.201800133
Journal or Publication Title:	ChemPhotoChem
Volume:	2
Number:	11
Page Range:	S. 964 - 976
Date:	2018
Publisher:	WILEY-V C H VERLAG GMBH
Place of Publication:	WEINHEIM
ISSN:	2367-0932
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Organic Chemistry
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language MOLECULAR-OXYGEN; PHOTOOXYGENATION; MECHANISM; OXIDATION; ALKENES; OLEFINS; O-1(2); REGIOSELECTIVITY; 1,2,4-TRIOXANES; INTERMEDIATE Multiple languages Chemistry, Physical Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/16777