Shifting the Reactivity of Bis-propargyl Ethers from Garratt–Braverman Cyclization Mode to 1,5-H Shift Pathway To Yield 3,4-Disubstituted Furans: A Combined Experimental and Computational Study

Regioselectivity of the 1,3-Dipolar Cycloaddition of Organic Azides to 7-Heteronorbornadienes. Synthesis of β-Substituted Furans/Pyrroles

An efficient procedure for the preparation of β-substituted furans/pyrroles is presented. The methodology is based on the use of 7-oxa/azanorbornadienes as dipolarophiles in 1,3-dipolar cycloaddition with benzyl azide. The triazoline cycloadduct thus formed spontaneously decomposes via a retro-Diels-Alder (rDA) reaction to afford a β-substituted furan/pyrrole derivative and a stable triazole. The scope of this tandem 1,3-dipolar cycloaddition/rDA reaction was studied with thirteen 7-heteronorbornadienes. This study allowed a deep knowledge of the regioselectivity of the reaction, which can be tuned through the substituents of the heteronorbornadienic systems.

Revisiting 1-chloro-1,2-benziodoxol-3-one: efficient ortho-chlorination of aryls under aqueous conditions

The ortho-selective amide directing group assisted chlorination of aryls with the easily accessible 1-chloro-1,2-benziodoxol-3-one as oxidant as well as chlorinating reagent is reported in the absence of a radical initiator. The open air, aqueous conditions and recyclable reagent demonstrate the green principles involved in the reaction.