Furanyl cyclic amines: a diastereoselective synthesis of 2,6-syn-disubstituted piperidines under thermodynamic control
作者:Matthew O'Brien、Andrew Leach、Roly J. Armstrong、Keting Chong、Ross Sheridan
DOI:10.1039/c2ob07008a
日期:——
Utilising the propensity of the 2-furanyl group to facilitate equilibration of an adjacent tosylamide chiral centre, a diastereoselective route to 2,6-syn-piperidines was developed that proceeds with high levels of thermodynamic stereocontrol. X-ray crystallography structures suggest that, as seen in similar systems, pseudo-allylic strain between the N-tosyl group and the substituents at the 2 and 6 positions dominates stereochemical preference, overriding 1,3 diaxial interactions.
利用 2-呋喃基团促进邻近对甲苯磺酰胺手性中心平衡的倾向,开发出了一种非对映选择性的 2,6-辛基哌啶路线,该路线具有很高的热力学立体控制能力。X 射线晶体学结构表明,正如在类似体系中看到的那样,N-对甲基苯磺酰基与 2 和 6 位上的取代基之间的假烯丙基应变主导了立体化学偏好,压倒了 1,3 二轴相互作用。