Iodine-mediated facile dehydrogenation of dihydropyridazin-3(2H)one

Nickel-catalyzed multicomponent reaction of dinitriles and hydrazine hydrochlorides with boronic acids: access to 1,3-diaryl-1H-pyrazol-5-amines and 4,5-dihydropyridazin-3(2H)-ones

“…Moreover, pyridazin-3(2 H )-one ( 8c ) was obtained in excellent yield through the late-stage oxidation process (Scheme 2, eqn (f)). 19…”

“…Moreover, pyridazin-3(2H)-one (8c) was obtained in excellent yield through the late-stage oxidation process (Scheme 2, eqn (f )). 19 The intermolecular competitive experiment of OMe-and CF 3 -substituted boronic acids was performed, and the result indicated that 2e showed better reactivity than 2o (Scheme 3, eqn (a)), indicating that electron-rich arylboronic acids show better efficiency. As for phenylhydrazine hydrochlorides, the substrate with electron-withdrawing substituents facilitated the reaction (Scheme 3, eqn (b)).…”

A New Method for the Preparation of Intermediates for 2,6‐Substituted Anthrapyridazones

“…In the second step, the alkylation of 3 required us to try a variety of electrophilic reagents as well as different solvents and temperature conditions in order to find the most efficient method. First of all, literature procedures for the alkylation of pyridazinones were tested. However, the attempts to directly transfer the published reaction conditions to the alkylation of 3 by 2‐(dimethylamino)ethyl chloride hydrochloride ( 4a ) failed.…”

Metal‐Free Iodine‐Catalyzed Oxidative Dehydrogenation of N‐Heterocycles

“…[7] In this content, the iodine-promoted oxidative reactions have attracted extensive attention. [8][9][10][11] Despite the advances, the current protocols have been limited to a few special N-heterocycles in oxidative dehydrogenative aromatization reactions. [9] For example, the construction of pyridiazin-3(2H)-ones, [9a] carbazoles, [9b] β-carbolines, [9c-e] and benzazoles/ benzazines [9f] with iodine as promoter have been developed by the Lokhande [9a-e] and Deng groups [9f] (Scheme 1b).…”

“…[9] For example, the construction of pyridiazin-3(2H)-ones, [9a] carbazoles, [9b] β-carbolines, [9c-e] and benzazoles/ benzazines [9f] with iodine as promoter have been developed by the Lokhande [9a-e] and Deng groups [9f] (Scheme 1b). Despite these remarkable achievements made, [9] most cases need peroxide/corrosive acid (HCl) [9c-e] or high temperature (160 °C), [9f] thus restricting their potential applications. Spurred by the above developments of the iodine-promoted oxidative aromatizations, [8][9][10] and in continuation of our studies on Nheteroarenes synthesis, [12] herein we wish to establish a general and convenient exploration of iodine-catalyzed oxidative methods for the construction of other new N-heteroarene scaffolds.…”