Universität zu Köln

Griesbeck, Axel G. ORCID: 0000-0002-6546-3482, de Kiff, Alan and Kleczka, Margarethe (2014). Tetraphenylporphyrin-Catalyzed Tandem Photooxygenation of Polyenes and 1,4-Dienes: Multiple and Diverse Oxyfunctionalizations. Adv. Synth. Catal., 356 (13). S. 2839 - 2846. WEINHEIM: WILEY-V C H VERLAG GMBH. ISSN 1615-4169

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Abstract

Tandem singlet oxygen reactions photocatalyzed by meso-tetraphenylporphyrin were performed with substrates designed for primary alpha-gem-selectivity or high vinylogous gem-selectivity. The 1,3,5-triene ester 1 was designed as a model compound for the natural compound crocin and resulted in a highly regioselective singlet oxygen ene reaction with e-hydrogen activation (93:7 ene vs. [4+2] cycloaddition). The initially formed hydroperoxide 2a adds another singlet oxygen molecule in a slower reaction step to furnish the endoperoxide 3a. From the hydroperoxide stage, oxygen transfer gives the epoxide 4, reduction leads to the allylic alcohol 2b and subsequent photooxygenation (to 3b) followed by reduction results in the furan derivative 5. The allylic alcohol could also be reacted with other dienophiles as shown for the PTAD adduct 6. From the 1,4-diene 7, a gem-regioselective singlet oxygen ene reaction generates a mixture of the hydroperoxides 8a and 9a. Product 8a adds another singlet oxygen molecule to give the endoperoxide 10a. Catalyst activity was demonstrated by analysis of the changes in the electronic absorption properties.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Griesbeck, Axel G. UNSPECIFIED orcid.org/0000-0002-6546-3482 UNSPECIFIED de Kiff, Alan UNSPECIFIED UNSPECIFIED UNSPECIFIED Kleczka, Margarethe UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-428647
DOI:	10.1002/adsc.201400565
Journal or Publication Title:	Adv. Synth. Catal.
Volume:	356
Number:	13
Page Range:	S. 2839 - 2846
Date:	2014
Publisher:	WILEY-V C H VERLAG GMBH
Place of Publication:	WEINHEIM
ISSN:	1615-4169
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 SINGLET-OXYGEN; RATE CONSTANTS; ENE-REACTION; MOLECULAR-OXYGEN; AQUEOUS-SOLUTION; DIENES; INTERMEDIATE; CAROTENOIDS; SENSITIZER; LYCOPENE Multiple languages Chemistry, Applied; Chemistry, Organic Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/42864