63922-76-9Relevant articles and documents
Photochemical Organocatalytic Regio- and Enantioselective Conjugate Addition of Allyl Groups to Enals
Berger, Martin,Carboni, Davide,Melchiorre, Paolo
, p. 26373 - 26377 (2021/11/16)
We report the first catalytic enantioselective conjugate addition of allyl groups to α,β-unsaturated aldehydes. The chemistry exploits the visible-light-excitation of chiral iminium ions to activate allyl silanes towards the formation of allylic radicals, which are then intercepted stereoselectively. The underlying radical mechanism of this process overcomes the poor regio- and chemoselectivity that traditionally affects the conjugate allylation of enals proceeding via polar pathways. We also demonstrate how this organocatalytic strategy could selectively install a valuable prenyl fragment at the β-carbon of enals.
Rational design of a second generation catalyst for preparation of allylsilanes using the silyl-Heck reaction
McAtee, Jesse R.,Yap, Glenn P. A.,Watson, Donald A.
supporting information, p. 10166 - 10172 (2014/08/05)
Using rational ligand design, we have developed of a second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yields of allylsilanes from simple alkene starting materials. The studies quantifying the electronic and steric properties of the new ligand are described. Finally, we report an X-ray crystal structure of a palladium complex resulting from the oxidative addition of Me3SiI using an analogous ligand that provides significant insight into the nature of the catalytic system.
Palladium-catalyzed allylic C-OH functionalization for efficient synthesis of functionalized allylsilanes
Selander, Nicklas,Paasch, Jennifer R.,Szabo, Kalman J.
supporting information; experimental part, p. 409 - 411 (2011/04/15)
A new method is described for palladium-catalyzed allylic silylation using allylic alcohols and disilanes as precursors. The reactions proceed smoothly under mild and neutral conditions, and this method is suitable for synthesis of regioand stereodefined allylsilanes. The presented silylation reaction can be easily extended to include synthesis of allylboronates by change of the dimetallic reagent. The presented synthetic procedure offers a broad platform for the selective synthesis of functionalized allyl metal reagents, which are useful precursors in advanced organic chemistry and natural product synthesis.
