Sn−Li Transmetalation of α‐Aminoorganostannanes for the Stereoselective Synthesis of Substituted Dehydropiperidines and Dehydroazepanes
作者:Alexandre Lumbroso、Isabelle Beaudet、Jean‐Paul Quintard、Cécile Fraisse、Nicolas Galland、Loïc Toupet、Erwan Le Grognec
DOI:10.1002/adsc.201900349
日期:2019.8.21
A highly diastereoselective synthesis of (R,S) or (S,S) 2,6‐disubstituted dehydropiperidines and 2,7‐disubstituted dehydroazepanes has been developed. The stereochemical preference for the (R,S) or the (S,S) isomer is governed by a tin‐lithium exchange/electrophilic trapping sequence combined with a ring‐closing metathesis. Their relative order was found to have a dramatic influence on the interaction
已开发出(R,S)或(S,S)2,6-二取代的脱氢哌啶和2,7-二取代的脱氢氮杂环庚烷的高度非对映选择性合成。(R,S)或(S,S)异构体的立体化学偏好是由锡-锂交换/亲电子捕获序列与闭环复分解相结合决定的。发现它们的相对顺序对控制阴离子中心差向异构的相互作用有很大的影响。在每种情况下,反应序列的完全立体发散都是通过考虑羰基锂配位带来的稳定性并通过DFT计算合理化来解释的。