A microwave-assisted three-component reaction was used to prepare a series of 1,4-disubstituted-1,2,3-triazoles from corresponding alkyl halides, sodium azide, and alkynes. This procedure eliminates the need to handle organic azides, as they are generated in situ, making this already powerful click process even more user-friendly and safe.

In the footsteps of Victor Grignard: The simple LiCl‐mediated insertion of magnesium into aryl chlorides and bromides at moderate temperatures leads to functionalized organomagnesium reagents (see scheme). An unprecedented range of functional groups may be present in the substrates (e.g. CN, CO2R, OTs, OBoc; Ts=p‐toluenesulfonyl, Boc=tert‐butylcarbonyloxy).

Cycloaddition reactions belong to one of the most well-investigated and widely used reactions in synthetic organic chemistry for the construction of (hetero)cyclic compounds in a single-step operation. In this tutorial review, a select number of examples of some [3+2] cycloadditions, i.e. for 1,2,3-triazole formation, as well as of some [4+2] and [2+2] cycloadditions are reviewed, where it has been proven that the application of microwave irradiation has a profound influence on the outcome of the reaction.

Inter- and intramolecular hetero-Diels-Alder reactions in a series of functionalized 2(1H)-pyrazinones were investigated under controlled microwave irradiation. The cycloaddition reactions were efficiently performed in sealed tubes, utilizing either a combination of 1,2-dichloroethane and a thermally stable ionic liquid, or 1,2-dichlorobenzene as reaction medium. In all cases, a significant rate-enhancement using microwave flash heating as compared to thermal heating was observed.

The development of new strategies for synthesis of medium-sized heterocycles has remained a highly attractive but challenging proposition. In the last few years, the application of microwave irradiation has greatly facilitated the construction of such heterocyclic ring systems through a myriad of different synthetic approaches. This feature article illustrates the progress made in the microwave-assisted synthesis of medium-sized heterocycles with an emphasis on examples describing the use of a dedicated microwave synthesizer.