Enantioselectivebromolactonization of trisubstituted olefinicacids producing synthetically useful chiral lactones with two contiguous asymmetric centers has remained mainly unexplored except for the 6‐exo cyclization mode. In this work, the 5‐exo‐ and 6‐endo modes of bromocyclization of trisubstituted olefinicacids were enabled for the first time using N‐bromosuccinimide and a pyridyl phosphoramide
A catalytic asymmetric bromocyclization of trisubstituted olefinic amides that uses a C(2)-symmetric mannitol-derived cyclic selenium catalyst and a stoichiometric amount of N-bromophthalimide is reported. The resulting enantioenriched pyrrolidine products, which contain two stereogenic centers, can undergo rearrangement to yield 2,3-disubstituted piperidines with excellent diastereoselectivity and