Pd-Catalyzed Regioselective Intramolecular Allylic C–H Amination of 1,1-Disubstituted Alkenyl Amines

Abstract

Pd-Catalyzed intramolecular allylic C–H amination of 1,1-disubstituted alkenyl amines with various allylic tethers (X = O, NMs, CH2) was developed. This process allows for the divergent synthesis of 1,3-X,N-heterocycles through a regioselective allylic C–H cleavage and π-allylpalladium formation. Particularly noteworthy is the use of substrates containing a labile allylic moiety and new simple catalytic systems capable of promoting highly chemo- and regioselective allylic C–H amination by overcoming significant challenges.

Synthesis of Quinazolinone-Fused Tetrahydroisoquinolines and Related Polycyclic Scaffolds by Iodine-Mediated sp3 C–H Amination

“…Classic approaches to the synthesis of these compounds include oxidative decarboxylative cyclization of isatins or isatoic anhydrides with dihydro- or tetrahydroisoquinolines , (Scheme a) and cyclization of anthranils or 2-nitro/2-amino benzyl alcohols with tetrahydroisoquinolines (Scheme b) . These compounds can also be synthesized by photoredox-catalyzed intramolecular radical cyanide insertion (Scheme c) or Lewis-acid-catalyzed annulation using triethoxymethane (HC­(OEt) 3 ) (Scheme d). , In recent years, significant progress has been made in the synthesis of quinazolinone-fused polycyclic compounds by C–H amination reactions of substrates bearing azide, nitro, amino, , or amide groups serving as the nitrogen source (Scheme e). In view of the significance of quinazolinone-fused polycyclic scaffolds, convenient and efficient methods to produce compounds of the type remain in high demand.…”

Construction of N-Ferrocene Substituted Benzodihydrooxazoles via a Catalyst-Free Aza-Michael Addition/C(sp3)-O Bond Formation Tandem Reaction

“…Tandem reactions, in which multiple transformations are combined in a single procedural step, have been widely employed for the construction of complex molecules Benzodihydrooxazoles are an important class of nitrogen and oxygen-containing heterocycles which are prevalent in natural products, bioactive molecules and many other functional molecules [20][21][22][23][24][25]. Considerable efforts have been devoted to the synthesis of this unique skeleton, strategies such as cyclization of 2-aminophenol, transition-metal-catalyzed intramolecular C-H amination reactions and coupling reactions of benzoxazoles have been discussed [22,[26][27][28][29][30][31][32][33][34][35][36]. However, the drawbacks of these methods are the requirement of strong acids or bases, participation of transition metal catalysts, lengthy steps and high reaction temperatures.…”

Simple Tandem Olefin Isomerization/Intramolecular Hydroamination of Alkenyl Amines with Various Allylic Tethers

“…As part of our continued interest in TM-catalyzed annulative reactions for heterocyclic synthesis, we herein report a simple and efficient AgOTf-promoted tandem olefin isomerization/intramolecular hydroamination of alkenyl amines (Scheme d). , Alkenyl amines with various allylic tethers (X = O, NR″, S) could be employed as substrates to afford diverse 1,3- X , N -heterocycles, which are ubiquitous motifs with broad applications found in a wide range of bioactive natural products, pharmaceuticals, and functional molecules. , Particularly noteworthy are the use of new and simple catalytic systems, the aerobic conditions in the absence of additional strong acids, the good chemical yields and functional group tolerance, the broad substrate scope, and the highly efficient and selective C­(sp 3 )–N bond formation in an atom-economic manner.…”