Divergent synthesis of pyrrolizine derivatives through C-H bond functionalization of pyrroles.

ABSTRACT

Presented herein is the synthesis of diversely functionalized pyrrolizines from the reaction of N-alkoxycarbamoyl pyrroles with CF3-ynones. The formation of the product is based on a C-H bond activation-initiated cascade process including N-alkoxycarbamoyl group-directed alkenylation of the pyrrole scaffold followed by simultaneous intramolecular nucleophilic addition along with cleavage and transfer of the directing group. By taking advantage of the rich chemistry of the transferred alkoxycarbamoyl moiety, the products could be transformed into a series of structurally and biologically interesting pyrrolizine derivatives. To our knowledge, this is the first example in which the N-alkoxycarbamoyl unit acted as a transferable and transformable directing group for the divergent synthesis of pyrrolizines.