Deaminative Cyclization of Tertiary Amines for the Synthesis of 2-Arylquinoline Derivatives with a Nonsubstituted Vinylene Fragment

Abstract

With triethylamine as a vinylene source, a convenient protocol for the regioselective synthesis of β,γ-nonsubstituted 2arylquinolines from aldehydes and arylamines has been accomplished. The deaminative cyclization is also extended to long-chain tertiary alkylamines, enabling diverse alkyl groups to be concurrently installed into the pyridine rings. This process demonstrates a new conversion pathway for the simultaneous dual C(sp 3 )−H bond functionalization of tertiary amines, wherein the transient acyclic enamines generated in situ undergo the Povarov reaction.

Benzannulation with Et3N as 1,3-Diene Variants

“…Moreover, only a trace amount of product 3a was found in the absence O 2 (Scheme 7d), which suggested that O 2 plays an essential role in the annulation procedure. According to the mechanistic investigations above and previous literature, a plausible explanation of the reaction mechanism is depicted in Scheme 20 Finally, the desired product 3 is produced through oxidative aromatization of O 2 .…”

“…The amide carbonyl α carbon nucleophilic attack on the imine cation causes cyclization into intermediate E . The Mannich-type intermediate E could be transformed into intermediate G via elimination of Et 2 NH at high temperature . Finally, the desired product 3 is produced through oxidative aromatization of O 2 .…”

Photocatalytic synthesis of 2,3-diamines from anilines and DIPEA via C–N bond cleavage and C–C bond formation

“…14 In addition, trialkylamines can be used as carbon sources to participate in the reaction and provide ethyl or methyl. 15 However, studies on trialkylamines as carbon sources have mostly focused on the construction of nitrogen-containing heterocycles. The use of trialkylamines to provide carbon chains in the synthesis of 2,3-diamines has not been reported yet.…”

TBHP Mediated C–N Bond Cleavage of Tertiary Amines toward the Synthesis of Oxalamides and α,β-Epoxy Amides

“…On the other hand, cleaving the highly stable C–N bond in tertiary amines and applying the fragments to construct new C–N or C–C bonds have aroused much attention. − However, previous investigations mainly focused on transition-metal catalysis processes. − In contrast, non-transition-metal catalysis for the activation of C–N bond has been rarely explored. Based on our previous work on β-ketoamides, herein, we present a simple and efficient protocol toward oxalamides by the reaction of β-ketoamides with tertiary amines via the tandem oxidation/amination process (Scheme d).…”