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A new synthetic route for biologically interesting pyranocarbazoles was developed by reaction of 2- or 4-hydroxycarbazole with α,β-unsaturated aldehydes in the presence of ethylenediamine diacetate (EDDA). The key strategy of this methodology is a formal [3+3] cycloaddition via domino aldol-type/6π- electrocyclization. The synthesized pyranocarbazoles can be converted into derivatives bearing substituents on the carbazole and pyran rings. [ABSTRACT FROM AUTHOR]

The front cover picture, provided by Yong Rok Lee and co ‐ worker, illustrates the catalytic application of silver for the construction of multifunctionalized azopyrazoles via cascade reaction of a ‐ diazo ‐ b ‐ keto esters and arylhydrazines. The synthesis of azopyrazoles bearing two different aromatic rings from 4 ‐ diazopyrazol ‐ 3 ‐ ones and aryhydrazine hydrochlorides is a unique advantage of this protocol. Silver ‐ catalyzed in situ pyrazole formation, N–H insertion, and oxidation have great potential for the advancement in the area of carbenoid chemistry. Details can be found in the full paper on pages 2657 – 2664 (R. P. Pandit, Y. R. Lee, Adv. Synth. Catal.­ 2015, 357, 2657 – 2664; DOI: 10.1002/adsc.201500197 [ABSTRACT FROM AUTHOR]

Wolff rearrangement of α-diazo-β-ketoesters (I) and (IV) followed by trapping of the ketene intermediates with enol ethers (II) and (V) generates a variety of trans-γ,δ-unsaturated β-ketoesters (III) and (VI), respectively. [ABSTRACT FROM AUTHOR]