Rh(III)-Catalyzed Cyclopropanation Initiated by C–H Activation: Ligand Development Enables a Diastereoselective [2 + 1] Annulation of N-Enoxyphthalimides and Alkenes
作者:Tiffany Piou、Tomislav Rovis
DOI:10.1021/ja506579t
日期:2014.8.13
N-Enoxyphthalimides undergo a Rh(III)-catalyzedC–Hactivationinitiatedcyclopropanation of electron deficient alkenes. The reaction is proposed to proceed via a directed activation of the olefinic C–H bond followed by two migratory insertions, first across the electron-deficient alkene and then by cyclization back onto the enol moiety. A newly designed isopropylcyclopentadienyl ligand drastically
Rhodium(III)-Catalyzed Cyclopropanation of Unactivated Olefins Initiated by C–H Activation
作者:Erik J. T. Phipps、Tiffany Piou、Tomislav Rovis
DOI:10.1055/s-0039-1690130
日期:2019.9
We have developed a Rh(III)-catalyzed cyclopropanation of unactivated olefins initiated by an alkenyl C-H activation. A variety of 1,1-disubstituted olefins undergo efficient cyclopropanation with a slight excess of alkene stoichiometry. A series of mechanistic interrogations implicate a metal-carbene as an intermediate.
Rh(III)-Catalyzed C–H Activation-Initiated Directed Cyclopropanation of Allylic Alcohols
作者:Erik J. T. Phipps、Tomislav Rovis
DOI:10.1021/jacs.9b02156
日期:2019.5.1
annulation onto allylic alcohols initiated by alkenyl C-H activation of N-enoxyphthalimides to furnish substituted cyclopropyl-ketones. Notably, the traceless oxyphthalimide handle serves three functions: directing C-H activation, oxidation of Rh(III), and, collectively with the allylic alcohol, in directing cyclopropanation to control diastereoselectivity. Allylic alcohols are shown to be highly reactive