Catalytic electronic activation as a tool for the addition of stabilised nucleophiles to allylic alcohols

This paper describes the activation of 2-cyclohexen-1-ol () and 2-cyclopenten-1-ol () through the use of aluminium-catalysed transfer hydrogenation. The electronically activated substrates are demonstrated to undergo facile conjugate addition and, when the alcohol functional group is subsequently restored in a one-pot procedure, this leads to an indirect addition of nucleophiles to allylic alcohols. This novel methodology has been termed catalytic electronic activation. The aluminium tert-butoxide catalysed conversion of 2-cyclohexen-1-ol () into 2-(3-hydroxycyclohexyl)-2-methylmalononitrile () and 2-cyclopenten-1-ol () into 2-(3-hydroxycyclopentyl)-2-methylmalononitrile () in 90 and 60% yield, respectively has been demonstrated through an efficient domino Oppenauer/Michael addition/Meerwein–Ponndorf–Verley process.