210890-19-0Relevant academic research and scientific papers
Stereoselective synthesis of highly substituted piperidines
Schneider, Christoph,B?rner, Christoph,Schuffenhauer, Ansgar
, p. 3353 - 3362 (2007/10/03)
Enantiopure piperidines 4 may be accessed in very good overall yields and high stereoselectivity from the bifunctional products 2 of the silyloxy Cope rearrangement of chiral aldol products 1 by sequential nucleophilic addition of primary amines and subsequent hydrogenation. The reaction is proposed to proceed by initial imine formation followed by an intramolecular aza-conjugate addition to the α,β-unsaturated imide. The stereoselectivity is controlled by A(1.2) strain between the imine N-alkyl group and the conjugate double bond. In an alternate approach, polyalkyl-substituted piperidines were prepared by the addition of organozinc reagents to cyanopiperidines readily obtained from the Cope products in the presence of a silver salt.
Novel and stereocontrolled synthesis of enantiopure and polyalkyl substituted piperidines
Schneider, Christoph,B?rner, Christoph
, p. 652 - 654 (2007/10/03)
A flexible and stereodivergent synthesis of enantiopure piperidines with up to four alkyl-substituted chiral centers is reported which proceeds by way of a double nucleophilic addition of primary amines to the 7-oxo-2-enimides 1. These in turn are accessible via the silyloxy-Cope rearrangement of chiral syn-aldol products.
