title: Kinetically controlled E-selective catalytic olefin metathesis.
abstract: A major shortcoming in olefin metathesis, a chemical process that is central to research in several branches of chemistry, is the lack of efficient methods that kinetically favor E isomers in the product distribution. Here we show that kinetically E-selective cross-metathesis reactions may be designed to generate thermodynamically disfavored alkenyl chlorides and fluorides in high yield and with exceptional stereoselectivity. With 1.0 to 5.0 mole % of a molybdenum-based catalyst, which may be delivered in the form of air- and moisture-stable paraffin pellets, reactions typically proceed to completion within 4 hours at ambient temperature. Many isomerically pure E-alkenyl chlorides, applicable to catalytic cross-coupling transformations and found in biologically active entities, thus become easily and directly accessible. Similarly, E-alkenyl fluorides can be synthesized from simpler compounds or more complex molecules.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
authors.forename: Thach T
authors.initials: TT
authors.lastname: Nguyen
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
authors.forename: Ming Joo
authors.initials: MJ
authors.lastname: Koh
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
authors.forename: Xiao
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.
authors.forename: Filippo
authors.initials: F
authors.lastname: Romiti
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Richard R
authors.initials: RR
authors.lastname: Schrock
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA. amir.hoveyda@bc.edu.
authors.forename: Amir H
authors.initials: AH
authors.lastname: Hoveyda