A computationally designed titanium-mediated amination of allylic alcohols for the synthesis of secondary allylamines
作者:Zunming Sun、Qingxia Wang、Yi Xu、Zhihong Wang
DOI:10.1039/c5ra18503c
日期:——
A computational design was inspired by previous mechanistic studies and the DFT-guided reactions were implemented in the synthesis of secondary allylamines. The participation of titanium imido intermediates facilitated the reaction and the closed transition states in the bond-forming steps rendered exclusive SN2′ substitution products.
以前的机理研究启发了计算设计,并且在仲烯丙胺的合成中实施了DFT指导的反应。钛亚氨基中间体的参与促进了反应,并且在键形成步骤中的闭合过渡态提供了唯一的S N 2'取代产物。
Direct C–H/N–H dehydrogenative coupling is a promising yet thermodynamically unfavorable transformation in the absence of a sacrificial hydrogen acceptor. Herein, a conceptually novel oxidant-free dehydrogenative amination of alkenes through a synergistic photoredox and cobaltcatalysis with H2 evolution has been achieved. With this approach, a wide range of five-membered N-heterocycles were synthesized
Transition Metal Free Cycloamination of Prenyl Carbamates and Ureas Promoted by Aryldiazonium Salts
作者:Roman Abrams、Quentin Lefebvre、Jonathan Clayden
DOI:10.1002/anie.201809323
日期:2018.10.8
O‐prenyl carbamates cyclize in a photocatalytic reaction with visiblelight and an organic dye. With electron‐deficient diazonium salts, electronic matching with an electron‐rich N‐aryl substituent results in a reaction proceeding in the ground state, without either light or photocatalyst. Cyclic voltammetry suggests that this radical reaction is initiated by hydrogen‐atomabstractionmediated by an aryl radical
in good yields by intramolecular hydroamination of N-alkoxy ureas in the presence of an organic photocatalyst and an inorganic base. In this reaction, the N-alkoxy urea anion generated by deprotonation undergoes photocatalyzed single-electron-transfer oxidation to generate the correspondingradical, which cyclizes to afford the imidazolinone ring. This new protocol grants access to an array of complex