Selective synthesis of β-nitrated N-heterocycles and N-nitroso-2-alkoxyamine aldehydes from inactivated cyclic amines promoted by ^tBuONO and oxoammonium salt

Abstract

Solvent-dependent-controlled selective synthesis of β-nitrated N-heterocycles and N-nitroso chain 2-alkoxyamine aldehydes has been successfully realized viatBuONO and oxoammonium salt promoted cascade reactions of inactivated cyclic amines.

Transition‐Metal‐Free Methods for the Remote C−H Bond Functionalization of Cyclic Amines

“…In 2019, Fan and co‐workers developed an oxidative β ‐nitration of N ‐aryl cyclic amines (Scheme 16). [39] The reaction uses t ‐butyl nitrite as the nitration reagent, which was proposed to generate nitrite radical in situ . 2,2,6,6‐Tetramethyl oxopiperidinium ion and for some substrates together with trifluoroborane etherate (BF 3 ⋅OEt 2 ) oxidize N ‐aryl cyclic amines to iminium ions, which subsequently form enamines by deprotonation.…”

Solvent-Regulated Coupling of 2-Alkynylbenzaldehydes with Cyclic Amines: Selective Synthesis of Fused N-Heterocycles and Functionalized Naphthalene Derivatives

“…Until now, while benzannulation of 2-alkynylbenzaldehydes with various unsaturated hydrocarbons was reported, the cycloaddition between 2-alkynylbenzaldehydes and inactivated cyclic amines with saturated chemical bonds to form fused N-heterocyclic compounds is still unknown. Thus, inspired by the elegant pioneering studies mentioned above and as a continuation of our work on the functionalization of cyclic amines, we herein report a new method for the synthesis of 1,2,3,4-tetrahydrobenzo­[ g ]­quinoline derivatives through PdCl 2 -catalyzed dehydrogenation/[4+2] cycloaddition of saturated cyclic amines with 2-alkynylbenzaldehydes (Scheme ).…”

“…On the basis of the experimental results mentioned above and previous reports, , two possible pathways for the formation of 3a are proposed in Scheme . Initially, 2a undergoes oxidation and subsequent dehydrogenation to produce enamine B .…”

Non-Directed β- or γ-C(sp3)–H Functionalization of Saturated Nitrogen-Containing Heterocycles

“…In 2019, Fan reported the oxidative -C(sp 3 )-H nitrification of piperidines with tBuONO (Scheme 23). 31…”