No abstract

Consecutive cyclization of allylaminoalkenes by tandem aminolithiation-carbolithiation proceeded smoothly by using a lithium amide as a lithiating agent as well as protonating agent to give bicyclic amines, octahydroindolizine and hexahydro-1 H-pyrrolizine, in reasonably high yield and diastereoselectivity.

Aminolithiation–carbolithiation tandem cyclization of an aminoalkene bearing vinyl sulfide moiety proceeded smoothly using stoichiometric amounts of BuLi. Both aminolithiation and carbo­lithiation were in equilibrium at room temperature, and the stereochemistry of the cyclization was thermodynamically controlled. At –78 °C the reaction was kinetically controlled and the cyclized product, 1,2-disubstituted octahydroindolizine, was obtained with good dia­stereoselectivity.