“On Water” Metal-Catalyst-Free Oxidative Coupling–Amidation of Amines To Access Imines and Amides

Abstract

A simple route toward the selective synthesis of imines and amides through oxidative coupling−oxidative amidation of amines using widely available NaOCl is presented. Under this approach, unprecedented one-pot synthesis of symmetrical and unsymmetrical secondary amides from primary amines as a single starting material is reported. This metalcatalyst-free protocol relies upon "on water" acceleration to obtain the desired products in high yields. An additive-based robustness screen was conducted to demonstrate the high reaction tolerance to several chemical motifs. Furthermore, mechanistic studies support a proposed pathway for the targeted oxidation products.

Anion–cation synergistic metal-free catalytic oxidative homocoupling of benzylamines by triazolium iodide salts

“…Strategies for conversion of amines to imines without involving metal-based catalysts offer benefits in terms of cost and purification. 1 To this end, diverse purely organic systems have been reported for this transformation, such as bleach, 19 catalytic AIBN, 20 graphene oxide, 21 bio-inspired ortho-quinone organocatalysts, 22 and salicylic acid derivatives, 23 the latter of which were also used to construct benzimidazoles. Photocatalytic reactions have been reported with WS 2 nanosheets 24 and truxene-based polymers.…”

Visible‐Light‐Induced Oxidation of Diazenyl‐Protected Tetrahydroisoquinolines and Isoindolines for the Synthesis of Functionalized Lactams

“…In the recent developments in this field, the direct α‐oxidation of tetrahydroisoquinolines and isoindolines is receiving a great deal of attention and proved to be a useful, efficient and direct strategy (Scheme 1a) [8] . Nevertheless, most protocols require harsh reaction conditions (e. g., higher reaction temperature [8d] and longer reaction times [8c] ) or using environmentally undesirable organic or inorganic oxidants such as TBHP, [8b,f] hypervalent iodine [8h] or chlorite, [8e] and transition metal catalyst (e. g., copper, [8a,g] manganese, [9] cobalt, [10] rhodium, [11] or iron [12] ). Compared to the use of common environmentally unfriendly organic and inorganic oxidants, the molecular oxygen has been suggested as an alternative to oxides organic substrates due to its atom‐economical, environmentally benign, and inexpensive character [13] .…”

Reversible detection of hypochlorite using the deprotonation–protonation strategy: a search for new building blocks

“…Sodium hypochlorite is a known oxidant in organic transformation reactions. 28 To examine the application of probe 1 to inhibit NaOCl induced oxidative coupling, we examined the oxidative coupling of benzylamine under standard conditions. In the control reaction under lab conditions, benzylamine was used as a reactant (Scheme S2, ESI †).…”