Solvent-free one-pot synthesis of 1,2,3-triazole derivatives by the 'Click' reaction of alkyl halides or aryl boronic acids, sodium azide and terminal alkynes over a Cu/Al 2 O 3 surface under ball-milling †

Highly selective reduction of nitroarenes has been achieved using iron metal nanoparticles in water at room temperature. A wide spectrum of reducible functionalities remained inert under the reaction conditions. During the reaction a change in shape of Fe nanoparticles was observed.

A convenient, efficient, and general procedure for the synthesis of diaryl chalcogenides including sulfides, selenides and tellurides has been developed by the reaction of diazonium tetrafluoroborates and diaryl dichalcogenides on the surface of alumina under ball-milling without any solvent or metal. A wide range of functionalized diaryl chalcogenides are obtained in high purity by this procedure.

Among the many types of transition-metal-catalysed C–C bond forming reactions, olefin metathesis is without a doubt one of the most thriving fields in modern organic synthetic chemistry.

Traditionally, a metal‐catalyzed cross‐coupling reaction is governed by displacement of leaving groups such as halogens, tosylates, etc. by different nucleophiles leading to the formation of carbon‐carbon and carbon‐heteroatom bonds. Besides displacement of traditional leaving groups in coupling reactions decyanative cross‐coupling has also received current attention. The objective of this work is to develop a decyanative cross‐coupling through metal‐assisted nucleophilic displacement, which is less explored so far. Thus, a decyanative cross‐coupling of aryl selenocyanate with aryl‐/alkylacetylenes, boronic acids and silanes has been accomplished by a copper‐assisted nucleophilic displacement reaction for an easy access to a series of diaryl, aryl alkyl, aryl vinyl and aryl alkynyl selenides. The best yield of product was obtained using 5 mol% of Cu(OAc)2, Ag2CO3 (20 mol%) and Cs2CO3 (1 equiv.) at 100 °C for 8 h in N‐methylpyrrolidinone (NMP). The advantages of simple operation, high yields and general applicability make this procedure more attractive. A mechanistic pathway has been proposed. Silver plays a key role in the decyanation process. A plausible mechanistic pathway of this decyanative carbon‐selenium cross‐coupling has been proposed based on UV, EPR, HR‐MS and IR analytical data along with results obtained from control experiments.magnified image