A Study of the Reactions of 3‐Bromopropenals with Anilines for the Synthesis of α‐Bromo Enaminones

Abstract

A one-pot strategy for the synthesis of α-bromo enaminones is reported. The reactions proceed via the p-toluenesulfonic acid monohydrate (TsOH • H 2 O) catalyzed reactions of 3-bromopropenals with anilines in dimethyl sulfoxide (DMSO) and does not require an external brominating agent. The chemoselective 1,2addition was accomplished by employing aniline with a sterically hindered electron-withdrawing group attached at the ortho-position. In addition, the reactions involving other aniline derivatives as nucleophiles have resulted in minor yields of 1,4-addition product. The 3-bromopropenals showed a diverse range of reactivities with aniline derivatives.

A NaHCO3 Promoted Three‐component Cyclization: Easy Access to Benzodisulfide Heterocycles

“…[32] Inspired by this, in the combination with our previous researches on the use of cheap inorganic bases in organic synthesis, [39,40] we utilized the decarboxylation of 2-halophenylacetic acids with a ring-forming reaction site in the presence of aromatic amines and S 8 as reactants to construct cyclic disulfide compounds. [25,32,[35][36][37][38] Because there are many kinds of aromatic amines as well, [41,42] our new three-component reaction can be used as a new method for the synthesis of benzene disulfide heterocyclic compounds with high efficiency, green and easily available starting materials.…”

Coupling of acceptor-substituted diazo compounds and tertiary thioamides: synthesis of enamino carbonyl compounds and their pharmacological evaluation

“…Due to their importance in synthesis, several methods exist for preparing enamino carbonyl compounds. 2,3,5,6 However, only a few of these methods make enamino carbonyl compounds with an exocyclic double bond (Fig. 1).…”

BPO-promoted [4 + 2] cyclization of enaminones and o-phenylenediamines to 2-acyl quinoxalines via a cascade transamination and C–H amination

“…9 Thus, the development of highly efficient strategies for accessing 2-acyl quinoxalines has attracted much attention from the synthetic community. [10][11][12][13][14][15][16][17] General approaches for the direct construction of such architectures mainly focused on Minisci acylation of quinoxalines, which are pre-prepared from o-phenyle-nediamines and oxalaldehyde (Scheme 1b). For example, Zeng's group have reported the electrochemical Minisci acylation of quinoxalines using α-keto acids as acyl radical precursors and NH 4 I as a redox catalyst.…”