Synthesis of enantiopure benzyl homoallylamines by indium-mediated barbier-type allylation combined with enzymatic kinetic resolution: Towards the chemoenzymatic synthesis of N-containing heterocycles

Abstract

Barbier-type indium-mediated allylations of different N, N(dimethylsulfamoyl)-protected aldimines with a number of allyl bromides followed by high-yielding deprotection afforded allylic amines in good to excellent yields, The racemic amines were then subjected to enzymatic kinetic resolution in order to obtain the corresponding (S)-amines and (R)amides. When acyl donors with a terminal double bond were applied in the enzymatic kinetic resolution, the product amide could be converted into unsaturated lactams in a straightforward manner by utilizing ring-closing metathesis. Furthermore, the enantiopure (S)-l-phenylbut-3-enylamine was converted into the corresponding diallylamine, which was subjected to ring-closing metathesis to yield a substituted dehydropiperidine mimicking a number of natural products. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.