School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, U.K.
School of Chemistry, University of Bristol , Cantock's Close, Bristol BS8 1TS, U.K.
Org Lett. 2017 Feb 3;19(3):472-475. doi: 10.1021/acs.orglett.6b03603. Epub 2017 Jan 18.
Treatment of N'-aryl urea derivatives of enantiomerically enriched α-(2-pyridyl) and α-(3-pyridyl)alkylamines with a base leads to the migration of the N'-aryl substituent from N to C in a 'nonclassical' intramolecular nucleophilic aromatic substitution reaction. Both electron-rich and -poor rings migrate successfully. A new quaternary stereogenic center is formed adjacent to the pyridine ring with high stereospecificity, even when the intermediate anion is a presumably planar 2-picolyllithium. Base hydrolysis of the urea gives enantiomerically enriched α-pyridylalkylamines.
用碱处理对映体富集的α-（2-吡啶基）和α-（3-吡啶基）烷基胺的 N'-芳基脲衍生物，导致 N'-芳基取代基从 N 到 C 的“非经典”分子内亲核芳香取代反应迁移。富电子和缺电子环都成功迁移。在吡啶环的相邻位置形成了一个新的具有高立体特异性的季立体中心，即使中间阴离子是假定的平面 2-吡啶基锂。脲的碱水解得到对映体富集的α-吡啶基烷基胺。
