Rh(I)/(III)‐N‐Heterocyclic Carbene Complexes: Effect of Steric Confinement Upon Immobilization on Regio‐ and Stereoselectivity in the Hydrosilylation of Alkynes
作者:Pradeep K. R. Panyam、Boshra Atwi、Felix Ziegler、Wolfgang Frey、Michal Nowakowski、Matthias Bauer、Michael R. Buchmeiser
DOI:10.1002/chem.202103099
日期:2021.12.6
Novel Rh(III) pentamethylcyclopentadienyl and Rh(I) complexes containing chelating N-heterocycliccarbenes have been prepared and used in the hydrosilylation of 1-alkynes. Selected catalysts were immobilized within the mesopores of SBA-15. The confinement effects either provided by the ligands or the mesoporous support have been studied and allow for hydrosilylation with β(Z)-selectivity of up to 100 %
Efficient access to polysubstituted tetrahydrofurans by electrophilic cyclization of vinylsilyl alcohols
作者:Asunción Barbero、Héctor Barbero、Alfonso González-Ortega、Francisco J. Pulido、Patricia Val、Alberto Diez-Varga、Joaquín R. Morán
DOI:10.1039/c5ra06640a
日期:——
Stereocontrolled access to polysubstituted tetrahydrofurans from organosilanes.
通过有机硅烷对多取代四氢呋喃的立体控制访问。
Hydrosilylation of alkynes catalyzed by ruthenium carbene complexes
作者:Sarah V. Maifeld、Michael N. Tran、Daesung Lee
DOI:10.1016/j.tetlet.2004.11.025
日期:2005.1
Hydrosilylation of terminal alkynes with a variety of silanes catalyzed by Cl2(PCy3)2RuCHPh (1) affords mainly the Z-isomer via trans addition in excellent yields. The presence of a hydroxyl group in close proximity to the triple bond was observed to exert a strong directing effect, resulting in the highly selective formation of the α-isomer. Intramolecular hydrosilylation of a homopropargylic silyl
Stereospecific Synthesis of Cyclobutylboronates through Copper(I)-Catalyzed Reaction of Homoallylic Sulfonates and a Diboron Derivative
作者:Hajime Ito、Takashi Toyoda、Masaya Sawamura
DOI:10.1021/ja101793a
日期:2010.5.5
A copper(I)-catalyzed stereospecific reaction for the preparation of cis- and trans-1-silyl-2-borylcyclobutanes as well as 1-phenyl-2-borylcyclobutanes is reported. (Z)- and (E)-Homoallylic methanesulfonates were converted to the corresponding trans- and cis-cyclobutane derivatives, respectively, in the presence of a CuCl/dppp catalyst, bis(pinacolato)diboron, and K(O-t-Bu)/THF. Stereospecific derivatizations
Silicon-directed stereoselectivesyn addition of hydroxy group to olefinic double bond occurs intramolecularly in an acid-catalyzed cyclization of vinylsilanes bearing hydroxy group. Thus 5-dimethylphenylsilyl-4-penten-1-ol is smoothly cyclized to 2-(dimethylphenylsilyl)methyltetrahydrofuran upon the treatment of a catalytic amount ofp-toluenesulfonic acid (TsOH) or TiCl4.