Copper-catalyzed interrupted click reaction: The synthesis of 3-difluoromethyl-substituted 1,2,4-triazinones

Each Interruption is an Opportunity: Novel Synthetic Strategies Explored Through Interrupted Click Reactions

The particular and unique mechanism of the copper-catalyzed reaction between azides and alkynes (CuAAC) has not only allowed for the efficient synthesis of 1,2,3-trisubstituted 1,4-triazoles in excellent yields and under mild conditions, becoming the quintessential click reaction, but it has also enabled the straightforward formation of a metallocycle intermediate, the copper triazolyl. This, under suitable reaction conditions able to suppress its protonolysis, can be used either for the creation of new bicyclic triazolyl structures or for the generation of novel three or four-component reactions. The aim of this review is to rationalize and unify all these transformations, which are collectively referred to as "interrupted click reactions".

Fluorination and fluoroalkylation of alkenes/alkynes to construct fluoro-containing heterocycles

This review summarize the established strategies through fluorination and fluoroalkylation of alkenes/alkynes for constructing fluoro-containing heterocycles. Reaction scopes, mechanisms and some shortcomings are also discussed.

Silver-catalyzed decarboxylative radical relay difluoroalkylation–carbocyclization: convenient access to CF2-containing quinolinones

A practical Ag-catalyzed formal decarboxylation and radical difluoroalkylation–carbocyclization–hydrolysis route is established to construct a series of structurally diverse CF2-containing N-heterocycles.

Copper-catalyzed [4 + 2] annulation reaction of β-enaminones and aryl diazonium salts without external oxidant: synthesis of highly functionalized 3H-1,2,4-triazines via homogeneous or heterogeneous strategy

Herein, both homogeneous and heterogeneous strategies were developed to access highly functionalized 3H-1,2,4-triazines using Cu-catalyzed [4 + 2] annulation.