title: Highly stereoselective radical carbonylations of gem-dihalocyclopropane derivatives with CO.
abstract: A couple of radical carbonylations of gem-dihalocyclopropanes 1 using CO and Bu3SnH (formylation) or Bu3Sn(CH2CH=CH2) (allylacylation) successfully proceeded to give trans and cis adducts (2 and 3) with good to excellent stereoselectivity (trans/cis = >99/1-75/25 or 17/83-1/99). The formylation of 2,3-cis-disubstituted 1,1-dihalocyclopropanes enhanced trans selectivity (trans/cis = >99/1-95/5), whereas both 2,3-cis-disubstituted and 2-monosubstituted 1,1-dihalocyclopropanes underwent allylacylation with nearly complete trans selectivity (trans/cis = >99/1). Inherently less reactive gem-dichloro- and bromochlorocyclopropanes than gem-dibromocyclopropanes served as favorable substrates. [reaction: see text].
authors.affiliation: Department of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan. nishii@shinshu-u.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nishii
authors.forename: Takao
authors.initials: T
authors.lastname: Nagano
authors.forename: Hideki
authors.initials: H
authors.lastname: Gotoh
authors.forename: Ryohei
authors.initials: R
authors.lastname: Nagase
authors.forename: Jiro
authors.initials: J
authors.lastname: Motoyoshiya
authors.forename: Hiromu
authors.initials: H
authors.lastname: Aoyama
authors.forename: Yoo
authors.initials: Y
authors.lastname: Tanabe