Premium
Enantiomerically Pure Amines as Substrates for the Ti‐Catalyzed Hydroamination of Alkynes
Author(s) -
Pohlki Frauke,
Bytschkov Igor,
Siebeneicher Holger,
Heutling Andreas,
König Wilfried A.,
Doye Sven
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300522
Subject(s) - hydroamination , racemization , chemistry , catalysis , pyridine , organic chemistry , medicinal chemistry , enantioselective synthesis , nitrogen atom , combinatorial chemistry , alkyl
For two representative reactions employing enantiomerically pure ( S )‐1‐phenylethylamine and ( S )‐1‐cyclohexylethylamine it is shown that Ti‐catalyzed hydroamination reactions of alkynes do not generally take place without partial racemization at the chiral center adjacent to the nitrogen atom. However, identified from a selection of nine Ti catalysts, Cp* 2 TiMe 2 and at least two other catalysts can be used for racemization‐free hydroamination reactions of alkynes. Furthermore, the amount of racemization can be reduced significantly by the addition of pyridine to the reaction mixture. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)