Direct Access to Quinazolines and Pyrimidines from Unprotected Indoles and Pyrroles through Nitrogen Atom Insertion

Modular synthetic strategies for dipyrrolopyrazines

“…Additionally, we demonstrated the functionalisation of the pyrrole and NH-moieties substantiating the versatility of the dipyrrolopyrazines for further extension of the π-system or potential molecular editing reactions. 43–45 The accompanying photophysical characterisation showed high quantum yields and fluorescence stability for blue-emitting compounds. 30 This, in combination with the exceptional thermal stability demonstrates that dipyrrolopyrazines serve as strong candidates for applications in materials science.…”

Precision single-atom editing: new frontiers in nitrogen insertion and substitution for the generation of N-heterocycles

“…Under similar reaction conditions, the Morandi group successfully inserted nitrogen atoms between C2 and C3 of unprotected indoles and pyrroles, resulting in the synthesis of quinazolines and pyrimidines. 30…”

Oxidative nitrogen insertion into silyl enol ether C=C bonds

“…Reshuffling C-C bond connectivity in the course of nitrogen incorporation has many advantages, including the ability to access functional group-rich arrays or skeletal architecture that may be difficult to obtain by other means [4][5][6] or the ability to achieve late-stage skeletal diversification of natural products or drug candidates. [7][8][9] Of particular interest are electrophilic ammonia surrogates, which allow nitrogen incorporation without requirement for specific substituents. Within this area of investigation, ammonium salts in the presence of an iodine(III) reagent have shown considerable promise 10 since their first report in 2016 for the oxidative amination of sulfoxide to sulfoximines (see Figure 1A, panel 1).…”

“…Within this area of investigation, ammonium salts in the presence of an iodine(III) reagent have shown considerable promise 10 since their first report in 2016 for the oxidative amination of sulfoxide to sulfoximines (see Figure 1A, panel 1). 11 The reactivity diversity possible with this reagent combination is exemplified by the variety of oxidation modes observed, including formal two-electron, 11 four-electron, [4][5][6][7][8][9][12][13][14] and six-electron oxidations (vide infra). Under the reaction conditions, ammonia and PhI(OAc)2 are proposed to give an "iodonitrene"-like species that serves as the active aminating agent.…”

“…Recent reports of related transformations of cyclic (hetero)aromatic nucleophiles (see Figure 1A, panel 2) provide important precedent for the potential power of this approach. [7][8][9] However, the chemistry of acyclic and aliphatic substrates for skeletal rearrangement upon nitrogen incorporation remains largely unexplored. In this work, we describe oxidative C=C cleavage of cyclic and acyclic silyl enol ethers using a combination of ammonium salt and iodine(III) reagent, affording Nacyl-N,O-acetals (see Figure 1B).…”