facile synthesis of biologically important trans-functionalized cyclopentenes by a mild Rh(III)-catalyzed alkylation of strained diazabicyclic olefins with aryl ketones in the presence of ammonium acetate has been developed. The reaction proceeds through C–H bond activation of the aryl ketone groups by transforming them in to an autocleavable directing group, such as in situ-formed imine.
Rhodium(III)-catalyzed ring-opening of strained olefins through C–H activation of O-acetyl ketoximes: an efficient synthesis of trans-functionalized cyclopentenes and spiro[2.4]heptenes
作者:E. Jijy、Praveen Prakash、M. Shimi、S. Saranya、P. Preethanuj、Petri M. Pihko、Sunil Varughese、K.V. Radhakrishnan
DOI:10.1016/j.tetlet.2013.10.089
日期:2013.12
An efficient strategy for the stereoselectivesynthesis of functionalized cyclopentenes and spiro[2.4]heptenes from strained olefins via C–H activation of aryl ketone O-acetyl ketoximes using [RhCl2Cp∗]2 catalyst is described. The results revealed that a wide range of readily accessible aryl and heteroaryl ketoximes are compatible in this method for the ring opening of bicyclic and spirotricyclic olefins
Selective C-2 functionalization of N-protected and free indoles is reported. The ruthenium-catalyzed C-2 activation of indoles provided an easyaccess to cyclopentenylated indoles. Hydroheteroarylated bicyclic motifs were synthesized via iridium-catalyzed C-2 activation of NH indoles. The methodology was extended to different bicyclic adducts such as diaza- or urea-derived bicyclic olefins.
Reactivity and Selectivity in Hydrovinylation of Strained Alkenes
作者:Wang Liu、T. V. RajanBabu
DOI:10.1021/jo1015135
日期:2010.11.19
alkenes such as heterobicyclic [2.2.1]heptanes and cylobutenes. Reactions involving the heterobicyclic compounds are rare examples for this class of compounds where the metal-catalyzed C−C bond-forming reactions proceed without a concomitant ring-opening process. While the enantioselectivity in these systems remains modest, hydrovinylation of endo-5,6--bis-benzyloxymethylbicyclo[2.2.1]hept-2-ene gives
Rhodium(III)-Catalyzed C–H Activation of Phenylazoles toward C–N Bond Cleavage of Diazabicyclic Olefins: A Facile Access to Mono- and Biscyclopentenyl-Functionalized Aza-Heteroaromatics
A [RhCl2Cp*] 2 -catalyzed stereoselective C–N bond cleavage of diazabicyclic olefins via C–Hactivation of phenylazoles in the presence of an acetate source is described. The developed method provides an easy access to biologically significant mono- and biscyclopentenyl- and alkylidenecyclopentenyl-functionalized aza heteroaromatics.