Organocatalytic Enantioselective Synthesis of Tetrahydrofluoren-9-ones via Vinylogous Michael Addition/Henry Reaction Cascade of 1,3-Indandione-Derived Pronucleophiles

Autor: Lennart Möhlmann, G. Madhusudhan Reddy, Geng Hua Chang, Chia Jui Lee, Wenwei Lin
Rok vydání: 2016
Předmět:
Zdroj: Organic letters. 18(4)
ISSN: 1523-7052
Popis: An unprecedented organocatalytic enantioselective vinylogous Michael addition/Henry cyclization cascade is presented for the synthesis of highly substituted tetrahydrofluoren-9-ones 3 employing novel 1,3-indandione-derived pronucleophiles 1a–g and nitroalkenes 2. Following a very simple protocol, a wide range of products were obtained in good to excellent yields and with excellent enantioinduction (43–98% yield, up to 98% ee). The reaction proceeded with excellent diastereocontrol despite the simultaneous generation of four stereogenic centers. Surprisingly, when 2-(1-phenylethylidene)-1H-indandione (1h) was used as a pronucleophile, no cyclization was observed, and only Michael addition adducts 4a–x were furnished in very good yields and excellent enantioselectivities.
Databáze: OpenAIRE