Nitroepoxides as Versatile Precursors to 1,4-Diamino Heterocycles
摘要:
Nitroepoxides are easily transformed into 1,4-diamino heterocycles such as quinoxalines and pyrazines by treatment with 1,2-benzenediamines and ammonia, respectively. Additionally, related saturated heterocycles, such as piperazines and tetrahydroquinoxalines, can be accessed by treatment with 1,2-diamines and a reducing agent. These transformations are efficient, provide access privileged, bioactive structures, and produce minimal waste.
Nitroepoxides as Versatile Precursors to 1,4-Diamino Heterocycles
摘要:
Nitroepoxides are easily transformed into 1,4-diamino heterocycles such as quinoxalines and pyrazines by treatment with 1,2-benzenediamines and ammonia, respectively. Additionally, related saturated heterocycles, such as piperazines and tetrahydroquinoxalines, can be accessed by treatment with 1,2-diamines and a reducing agent. These transformations are efficient, provide access privileged, bioactive structures, and produce minimal waste.
ABSTRACT Substituted2-aminothiazoles have been synthesized from α-nitro-epoxides, cyanamide, and sodium sulfide through a facile, three-component, and ecofriendly protocol with good to excellent yields. This reaction was achieved at room temperature without any additives. A possible mechanism has also been proposed. GRAPHICAL ABSTRACT
A multi-component synthesis of N-substituted 2-amino-3-cyano pyrroles from nitroepoxides, amines and malononitrile has been demonstrated. The reaction proceeded well for a wide range of nitroepoxides and amines under mild conditions without transition metal catalysis via the formation of three new bonds.
A novel and efficient reaction has been developed to synthesize a set of substituted 2-aminothiazoles from α-nitroepoxides and ammonium thiocyanate. This reaction could proceed smoothly at mild condition, to afford products for a wide range of substrates with good to excellent yields. A possible mechanism has also been proposed.
An efficient synthesis of 2,4,5-trisubstituted thiazoles via the reaction of α-nitroepoxides and thioureas under mild conditions has been developed. This reaction proceeded well at room temperature, to afford products in excellent yields for a wide range of substrate, and a possible mechanism has also been proposed.
A novel and facile one-pot reaction has been developed to synthesize a variety of penta-substituted pyrroles from α-nitroepoxides, primary amines and dialkyl acetylenedicarboxylates under the conditions without catalyst. Furthermore, the controlled experiments has been performed and a possible mechanism has also been proposed.