Iron(III)-Mediated Rapid Radical-Type Three-Component Deuteration of Quinoxalinones With Olefins and NaBD4

Abstract

Iron(III)-promoted rapid three-component deuteration of quinoxalinones with olefins and NaBD 4 is reported for the first time, which provides a novel, economic, and efficient method for the rapid synthesis of deuterated quinoxalinones. In this transformation, a radical pathway is involved according to the results of control experiments.

Recent Developments for the Deuterium and Tritium Labeling of Organic Molecules

“…Moreover, the convenient reaction conditions of this labeling technique should be mentioned, as the products are obtained at room temperature in short time (30 min). A related deuteration of quinoxalinones with NaBD 4 and olefins was recently established by Li and co-workers via a three-component reaction following a radical pathway . Sodium borodeuteride was used as isotope source, allowing the functionalization of diverse quinoxalinones.…”

“…A related deuteration of quinoxalinones with NaBD 4 and olefins was recently established by Li and co-workers via a three-component reaction following a radical pathway. 354 Sodium borodeuteride was used as isotope source, allowing the functionalization of diverse quinoxalinones. However, the substrate scope is limited to this type of backbone as theophyllines and quinazolines did not undergo similar reactions.…”

Regiospecificity C(sp2)–C(sp3) Bond Construction between Purines and Alkenes to Synthesize C6-Alkylpurines and Purine Nucleosides Using O2 as the Oxidant

“…According to the results of mechanistic studies and previous studies, ,, a plausible mechanism was proposed (Scheme ). Initially, a formal hydrogen radical is formed via single-electron oxidation of the hydride by Fe 3+ salt, which will add to alkenes to generate more stable secondary alkyl radical A , but not primary radical A′ .…”

“…20 Subsequently, Li et al reported a similar method with iron(III)-promoted rapid radical-type three-component deuteration of quinoxalinones with olefins and NaBD 4 . 21 In their case, most substrates usually just own one reactive C−H position (Scheme 1D). However, there has been no report on the direct C 6 -alkylation between alkenes and purines, in which the potential regioselectivity issues caused by three C−H positions (C 2 −H, C 6 −H, and C 8 −H) remain difficult to tackle.…”

“…. Subsequently, Li et al reported a similar method with iron­(III)-promoted rapid radical-type three-component deuteration of quinoxalinones with olefins and NaBD 4 . In their case, most substrates usually just own one reactive C–H position (Scheme D).…”