Cross-Metathesis of Chiral N-tert-Butylsulfinyl
Homoallylamines: Application to the Enantioselective Synthesis of
Naturally Occurring 2,6-cis-Disubstituted Piperidines
Regio- and Stereoselective Monoamination of Diketones without Protecting Groups
作者:Robert C. Simon、Barbara Grischek、Ferdinand Zepeck、Andreas Steinreiber、Ferdinand Belaj、Wolfgang Kroutil
DOI:10.1002/anie.201202375
日期:2012.7.2
Hitting the right target: Differentiation between two keto moieties was accomplished by a regio‐ and enantioselective bioamination employing ω‐transaminases. Using 1,5‐diketones as substrates gave access to the opticallypure 2,6‐disubstituted piperidine scaffold. The approach allowed the shortest synthesis of the alkaloid dihydropinidine, as well as its enantiomer, by choosing an appropriate ω‐transaminase
Chemoenzymatic Synthesis of All Four Diastereomers of 2,6-Disubstituted Piperidines through Stereoselective Monoamination of 1,5-Diketones
作者:Robert C. Simon、Ferdinand Zepeck、Wolfgang Kroutil
DOI:10.1002/chem.201202793
日期:2013.2.18
evaluated for the stereoselective monoamination of designated 1,5‐diketones; excellent conversions, enantio‐ and regioselectivities were observed. The resulting amino‐ketones underwent spontaneous intramolecular ringclosure to afford Δ1‐piperideines, which served as precursors for the cis‐ and anti‐piperidine scaffold as demonstrated for the synthesis of the alkaloids dihydropinidine and epi‐dihydropinidine
Cross-Metathesis of Chiral <i>N</i>-<i>tert</i>-Butylsulfinyl
Homoallylamines: Application to the Enantioselective Synthesis of
Naturally Occurring 2,6-<i>cis</i>-Disubstituted Piperidines
The synthesis of piperidine alkaloids (+)-dihydropinidine (1), (+)-isosolenopsin (2a), (+)-isosolenopsin A (2b), and (2R,6R)-6-methylpipecolic acid (3a) hydrochlorides, based on cross-metathesis of chiral N-tert-butylsulfinyl homoallylamines with methyl vinyl ketone, is presented.