method for the efficient syntheses of optically active 1-alkyl homoallylic amines in yields up to 95%, 13.5:1 dr, and 98% ee under mild, aqueous reaction conditions, via the Rh-catalyzed asymmetric allylation of aliphatic aldimines. This method provides a streamlined synthetic platform for the preparation of indolizidine and piperidine alkaloids, thus demonstrating its usefulness.
Stereoselective Multicomponent Assembly of Enantiopure Oxazolopiperidines and -azepines
作者:Nicolas Zill、Angèle Schoenfelder、Nicolas Girard、Maurizio Taddei、André Mann
DOI:10.1021/jo202455c
日期:2012.3.2
efficient diastereoselective preparation of oxazolopiperidines (4a–e) and -azepines (7a–d). The bicyclic oxazolidines were obtained from chiral N-alkenylamino alcohols via transient cyclic iminium intermediates that underwent an intramolecular cyclization from the appendant oxygen. On the basis of a series of different experimental conditions, the diastereocontrol observed during the formation of the
Asymmetric synthesis of piperidines and octahydroindolizines using a one-pot ring-closure/N-debenzylation procedure
作者:Stephen G. Davies、Ai M. Fletcher、Deri G. Hughes、James A. Lee、Paul D. Price、Paul M. Roberts、Angela J. Russell、Andrew D. Smith、James E. Thomson、Oliver M.H. Williams
DOI:10.1016/j.tet.2011.09.038
日期:2011.12
The conjugate addition of an enantiopure lithium amide to a zeta-hydroxy-alpha,beta-unsaturated ester followed by a one-pot ring-closure/N-debenzylation protocol has been used in the asymmetric syntheses of (S)coniine and (R)-delta-coniceine (isolated as the corresponding hydrochloride salts), and (R,R)-1-(hydroxymethyl)octahydroindolizine (the bicyclic fragment of stellettamides A-C). (C) 2011 Elsevier Ltd. All rights reserved.
Asymmetric Synthesis of Piperidines and Octahydroindolizines
作者:Stephen Davies、Deri Hughes、Paul Price、Paul Roberts、Angela Russell、Andrew Smith、James Thomson、Oliver Williams
DOI:10.1055/s-0029-1219346
日期:2010.3
The conjugate addition of a homochiral lithium amide to a xi-hydroxy-alpha,beta-unsaturated ester, followed by a one-pot, ring-closure-N-debenzylation protocol has been used in the asymmetric syntheses of (S)-coniine and (R)-delta-coniceine (isolated as the corresponding hydrochloride salts) and the bicyclic core of stellettamide A.