title: Halodiazophosphonates, a new class of diazo compounds for the diastereoselective intermolecular Rh(II) catalyzed cyclopropanation.
abstract: (Halodiazomethyl)phosphonates 2A-C have been generated by a one-pot procedure via a clean, efficient, and rapid deprotonation/electrophilic halogenation sequence from diethyl diazomethylphosphonate 1 (EDP). Subsequent intermolecular Rh(II)-catalyzed cyclopropanation afforded the corresponding halocyclopropylphosphonates 3-10 in moderate to high yields and high diastereomeric ratios. Catalyst loadings down to 0.1 mol % as well as clean and selective product formation were achieved.
authors.affiliation: Department of Chemistry, University of Oslo, Sem Sælands vei 26, N-0315 Oslo, Norway.
authors.forename: Christian
authors.initials: C
authors.lastname: Schnaars
authors.forename: Tore
authors.initials: T
authors.lastname: Hansen