Formal α-Allylation of Primary Amines by a Dearomative, Palladium-Catalyzed Umpolung Allylation of <i>N</i>-(Aryloxy)imines
作者:Luis M. Mori-Quiroz、Shrikant S. Londhe、Michael D. Clift
DOI:10.1021/acs.joc.0c01020
日期:2020.12.4
N-(Aryloxy)imines, readily accessible by condensation/tautomerization of (pseudo)benzylic primary amines and 2,6-di-tert-butyl-1,4-benzoquinone, undergo efficient allylation to afford a wide range of homoallylic primary amines following hydrolytic workup. Deprotonation of N-(aryloxy)imines generates a delocalized 2-azaallyl anion-type nucleophile that engages in dearomative C–C bond-forming reactions
N-(芳氧基)亚胺很容易通过(伪)苄基伯胺和2,6-二叔丁基-1,4-苯醌的缩合/互变异构而获得,经过有效的烯丙基化反应后得到各种均一的伯胺水解后处理。N-(芳氧基)亚胺的去质子化产生离域的2-氮杂烯丙基阴离子型亲核试剂,与烯丙基碳酸叔丁酯生成的烯丙基钯(II)亲电试剂参与脱芳香族CC键形成反应。该反应性基质使(伪)苄基伯胺的形式α-烯丙基化成为可能。机理研究表明,所需键形成事件的表观区域选择性是由非选择性烯丙基化引发的聚合过程。N-(芳氧基)亚胺产生几种区域异构体,其随后通过逐步的[1,3]-或一致的[3,3]-σ位移而重排,最终收敛以提供所需的胺产物的区域异构体。