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Functionalized benzonitriles, α,β-epoxyketones and β-hydroxy-α-haloketones are found in numerous medicinally important molecules, whilst benzonitriles in combination with any of these functional groups may be of interest to medicinal chemists. However, the simultaneous incorporation of a nitrile group and these functional groups on the aromatic ring is a challenging task. Herein, we report a strategy for the rapid and simultaneous construction of structurally novel benzonitrile derivatives, possessing either an ortho -α-iodo-β-hydroxyketone, an α,β-epoxyketone or an α,β-enone, from unprotected, 2-[(3-hydroxy/acetoxy)propyn-1-yl]benzamides. This process involves NXS-promoted dehydration–halohydration followed by DIPEA-mediated epoxide formation (from alcohols). We have developed both stepwise and one-pot strategies to improve the synthetic efficiency. No metal catalyst is employed and the method exhibits good substrate scope and yields. [ABSTRACT FROM AUTHOR]

Herein we report the discovery and development of the first example of a cationic [1,5]‐aryl migration reaction, through an unprecedented phenonium ions. This reaction does not require any acid, base, transition metal‐based catalyst or promoter, instead promoted by the water activated NXS reagents. It provides a highly diastereoselective and rapid access to the medicinally and biologically important tetra‐substituted olefins (allyl alcohols). The involvement of an ipso‐carbon, as well as the phenonium ion during this novel, cationic [1,5]‐aryl migration was strongly supported by the isolation of 2‐oxaspiro[5.5]undecane‐9‐ones. This methodology is highly tolerable for a wide range of propargyl‐benzyl ethers, resulting in a selective construction of structurally divergent library of mono‐halo‐tricarbon‐substituted alkenes. Synthetic application has also been demonstrated by converting two isomeric‐iodo‐olefins to respective E‐ and Z‐isomers of tamoxifen in a stereospecific manner. [ABSTRACT FROM AUTHOR]