The Regioisomeric Triphenylaminoethanols–Comparison of their Efficiency in Enantioselective Catalysis

Autor:	Manfred Braun, Marc-André Schneider, Brigitte Mai, Stefan Lachenicht, Ralf Fleischer
Rok vydání:	2004
Předmět:	Benzaldehyde Diketone chemistry.chemical_compound Nucleophilic addition chemistry Enantioselective synthesis Organic chemistry Alcohol General Chemistry Enantiomer Diethylzinc Catalysis
Zdroj:	Advanced Synthesis & Catalysis. 346:474-482
ISSN:	1615-4169 1615-4150
Popis:	Both enantiomers of the novel amino alcohol (R)- and (S)-2 are prepared from the corresponding enantiomer of the mandelic acid-derived ethanediol 3. The regioisomeric amino alcohols 1 and 2 are converted into the imines 7 and 8, respectively. Titanium complexes 9 and 10 derived therefrom are used as catalysts for the addition of diethylzinc to benzaldehyde and yield the alcohol 11 in up to 92% ee. On the other hand, the chloro-substituted titanium complexes 14 and 15 are able to mediate the Torgov cyclization reaction of the diketone 16 to give the estrone derivative 17. In both reactions titanium complexes 10 and 15 derived of the novel amino alcohol 2 give higher enantioselectivities than the complexes 9 and 14 that are based on the regioisomeric amino alcohol 1.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8d3e92ae5c311895f7921a56a43d8f27 https://doi.org/10.1002/adsc.200303178 Zobrazit plný text záznamu Plný text