Dearomatization of electron poor six-membered N-heterocycles through [3 + 2] annulation with aminocyclopropanes

Autor:	Jerome Waser, Shyamal Chakrabarty, Johannes Preindl
Rok vydání:	2017
Předmět:	Annulation 010405 organic chemistry Chemistry Iminium Indolizidine General Chemistry 010402 general chemistry 01 natural sciences High yielding 0104 chemical sciences Catalysis chemistry.chemical_compound Nucleophile Organic chemistry
Zdroj:	Chemical Science
ISSN:	2041-6520
Popis:	Dearomative [3 + 2] annulation of N-heterocycles with donor–acceptor aminocyclopropanes: fast access to indolizidine building blocks. Many abundant and highly bioactive natural alkaloids contain an indolizidine skeleton. A simple, high yielding method to synthesize this scaffold from N-heterocycles was developed. A wide range of pyridines, quinolines and isoquinolines reacted with donor–acceptor (DA)-aminocyclopropanes via an ytterbium(iii) catalyzed [3 + 2] annulation reaction to give tetrahydroindolizine derivatives. The products were obtained with high diastereoselectivities (dr > 20 : 1) as anti-isomers. Additionally, the formed aminals could be easily converted into secondary and tertiary amines through iminium formation followed by reduction or nucleophile addition. This transformation constitutes the first example of dearomatization of electron-poor six-membered heterocycles via [3 + 2] annulation with DA cyclopropanes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f06e9889ca669c81df22049a22c05163 https://pubmed.ncbi.nlm.nih.gov/29147541 Zobrazit plný text záznamu