Rh(III)-catalyzed synthesis of isoquinolines using the N-Cl bond of N-chloroimines as an internal oxidant

Accurate experimental characterization of the labile N–Cl bond inN-chloro-N′-(p-fluorophenyl)-benzamidine crystal at 17.5 K

“…The interest in the N-Cl bond is motivated by the very rich chemistry it deploys. Its uses range from being an internal oxidant for the construction of an isoquinoline skeleton 10 to its cleavage in the Rh-catalyzed C-H amination of N-arylbenzamide with N-chloromorpholine, 11 to the enantioselective oxidation by chiral compounds bearing N-Cl bond 12 and to the antibacterial activity of N-halamines 13,14 As reported in a review of the synthesis, characterization, and applications of antimicrobial N-halamine polymers and coatings, 13 the oxidizing agent of molecules containing N-Cl bonds (usually chlorine) "can act through direct transfer of active element to the biological receptor or through dissociation to free halogen in aqueous media". 13 An early ab initio study 15 showed that the N-Cl bond is rather weak, and a more recent high-level quantum chemical study 16 highlights the effect of substituents on the strength of N-Cl bond dissociation energy.…”

Silver‐Free C−H Activation: Strategic Approaches towards Realizing the Full Potential of C−H Activation in Sustainable Organic Synthesis

“…The latter two studies delivered products with alkyl substituents in the 1‐position ( 53 e – f ), analogous to the ones obtained by Yi. Later, Zhu and co‐workers showed that analogous transformations are possible starting from an N−Cl bond as an internal oxidant [85] . Complementarily, in 2011 Miura reported that using oxadiazoles as starting materials products with an N ‐acyl group in the 1‐position can be generated ( 53 g , Scheme 21E) [86] .…”

A new outlook in oxidative transformations and coupling reactions via in situ generation of organic chloramines

“…Owing to the high coordinating and oxidizing reactivity of N ‐chloroimines, the same group reported Rh(III)‐catalyzed method for the synthesis of isoquinolines with N ‐chloroimines as an internal oxidant (Scheme 64). [ 111 ] The coupling of N ‐chloroimines with alkynes provides access to a varied range of isoquinoline derivatives The developed protocol features atom and step economy, use of green solvent (EtOH), and mild reaction conditions, with a broad substrate scope.…”