Studies towards a new one-pot heterocyclization: ButOK-promoted oxa- and aza-Michael addition–intramolecular carbocyclization of prop-2-ynyl alcohols and amines with α,β-disubstituted nitroalkenes
ButOK-promoted reaction of prop-2-ynyl alcohols 5 or N-methylprop-2-ynylamine 12 with nitroalkenes 1â4 affords 3-methylenetetrahydrofurans 6â9 and 3,4-dihydropyrans 10 and 11 or 3-methylenepyrrolidines 13â16, respectively, in moderate to good yields, with total allylic 1,3-strain-controlled diastereoselectivity.
Michael Addition Initiated Carbocyclization Sequences with Nitroolefins for the Stereoselective Synthesis of Functionalized Heterocyclic and Carbocyclic Systems
The synthesis of various heterocycles and carbocycles (tetrahydrofurans, pyrrolidines, cyclopentanes) has been achieved by using new and efficient ionic addition/cyclization sequences. Nitroolefins play an important role in the Michael addition induced ring‐closing reactions (MIRC) reported in the present article, with various substituted alcohols, amines, Grignard reactants, or malonate derivatives