title: A facile formal [2+1] cycloaddition of styrenes with alpha-bromocarbonyls catalyzed by copper: efficient synthesis of donor-acceptor cyclopropanes.
abstract: Reactions of 2-bromoesters and styrenes underwent a [2+1] cycloaddition reaction, i.e., cyclopropanation, to produce donor-acceptor (D-A) cyclopropanes through a radical addition-ring closure process. In this reaction, the combination of copper(ii) complex and amines is found to be a good catalyst system to obtain cyclic compounds in high yields. This reaction provides an efficient protocol to synthesize D-A cyclopropanes, which are very important building blocks in organic synthesis.
authors.affiliation: Graduate School of Science and Engineering, Yamaguchi University 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611, Japan. nisikata@yamaguchi-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishikata
authors.forename: Yushi
authors.initials: Y
authors.lastname: Noda
authors.forename: Ryo
authors.initials: R
authors.lastname: Fujimoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Ishikawa