title: Design and synthesis of planar chiral heterocyclic carbene precursors derived from [2.2]paracyclophane.
abstract: A unique family of planar chiral symmetrical N-heterocyclic carbene precursors with restricted flexibility derived from [2.2]paracyclopane were obtained by a new synthetic route. The resolution of 4-amino-13-bromo[2.2]paracyclophane was achieved with relatively high efficiency. Starting from (4 S p,13 R p)-4-amino-13-bromo[2.2]paracyclophane, the planar chiral pseudogem-disubstituted [2.2]paracyclophanyl dihydroimidazoliums were prepared in a four-step sequence with good yields. The resulting dihydroimidazolium salts were fully characterized with a series of methods including single-crystal X-ray diffraction technique.
authors.affiliation: Department of Chemistry, Shandong University, Shanda South Road No. 27, Jinan, People's Republic of China.
authors.forename: Wenzeng
authors.initials: W
authors.lastname: Duan
authors.forename: Yudao
authors.initials: Y
authors.lastname: Ma
authors.forename: Houqi
authors.initials: H
authors.lastname: Xia
authors.forename: Xueying
authors.initials: X
authors.lastname: Liu
authors.forename: Qingshuang
authors.initials: Q
authors.lastname: Ma
authors.forename: Junshan
authors.initials: J
authors.lastname: Sun