A chemo- and stereoselective reduction of cycloalkynes to (E)-cycloalkenes
作者:Alois Fürstner、Karin Radkowski
DOI:10.1039/b207169j
日期:——
A stereoselective entry into (E)-cycloalkenes is described, comprising the ring closing alkyne metathesis (RCAM) of suitable diynes, a ruthenium-catalyzed trans-selective hydrosilylation of the cycloalkynes thus formed, followed by a desilylation of the resulting vinylsilanes mediated by AgF.
as 15, 16 and 20 which themselves were shown to be catalytically active. Numerous applications illustrate the performance of the catalytic system 1/CH2Cl2 which operates under mild conditions and tolerates an array of polar functional groups. The wide scope allows the method to be implemented into the totalsynthesis of sensitive and polyfunctional natural products. Most notable among them is a concise
Ruthenium-Catalyzed <i>trans</i>-Hydroalkynylation and <i>trans</i>-Chloroalkynylation of Internal Alkynes
作者:Nagaraju Barsu、Markus Leutzsch、Alois Fürstner
DOI:10.1021/jacs.0c08582
日期:2020.11.4
[Cp*RuCl]4 catalyzes the addition of iPr3SiC≡CX (X = H, Cl) across internal alkynes with formation of 1,3-enyne or 1-chloro-1,3-enyne derivatives, respectively; the reaction follows an unorthodox trans-addition mode. The well-balanced affinities of the different reaction partners to the ruthenium catalyst ensure that crossed addition prevails over homodimerization of the individual components, as can
Synthèses de produits macrocycliques à odeur musquée. 8e communication Synthèse de la civettone naturelle
作者:M. Stoll、J. Hulstkamp、A. Rouvé
DOI:10.1002/hlca.19480310234
日期:——
e d'éthyle a été cyelisé en l'éthylène-cétal de la céto-9-cyclo-heptadécanol-1-one-17. Cette dernière a été réduite catalytiquement en l'éthy1ène-cétal des deux céto-9-cyclo-heptadécane-diol-l,17 diastéreoméres. Ceux-ci furent transformés en les deux bromo-aeétates correspondants qui donnèrent, par réduction au zinc, un mélange de civettone trans et de civettone cis.