The first one-pot Alder-ene-reductive amination sequence

Alkyne allyl alcohols 1 are cycloisomerized under Pd catalysis to give (4-alkylidene tetrahydrofuran-3-yl) acetaldehydes 2 in good yields. These mild reaction conditions are fully compatible with a subsequent reductive amination with secondary amines and formic acid. Thus, the cycloisomerization-reductive amination sequence of yne allyl alcohols 1 and secondary amines 3 furnishes β-amino ethyl alkylidene tetrahydrofurans 4 in moderate to good yields in a one-pot fashion.