title: Copper-Catalyzed trans-Hydroboration of Terminal Aryl Alkynes: Stereodivergent Synthesis of Alkenylboron Compounds.
abstract: A Cu-catalyzed highly Z-stereoselective hydroboration of alkynes with 1,8-naphthalenediaminatoborane (HB(dan)) is developed. DPEphos (bis[(2-diphenylphosphino)phenyl]ether)-ligated Cu catalysts produced alkenylboron compounds from terminal alkynes with excellent Z-stereoselectivity. In contrast, using a SIPr-CuCl complex as the precatalyst exclusively produced E-hydroboration products at mild conditions. Both catalytic procedures form alkenylboron products stereocomplementary to each other, constituting stereodivergent hydroboration of alkynes through Cu catalysis. Deuterium labeling and isomerization studies support the Z-selective hydroboration via trans-addition of the boron reagent to terminal alkynes as opposed to precedent noble-metal-catalyzed trans-hydroborations.
authors.affiliation: Department of Chemistry and Institute of Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Jang
authors.affiliation: Department of Chemistry and Institute of Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Woo Lim
authors.initials: WL
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Institute of Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Jong Hun
authors.initials: JH
authors.lastname: Moon
authors.affiliation: Department of Chemistry and Institute of Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Jin Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Institute of Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
authors.forename: Jaesook
authors.initials: J
authors.lastname: Yun