Photochemical Organocatalytic Regio‐ and Enantioselective Conjugate Addition of Allyl Groups to Enals
作者:Martin Berger、Davide Carboni、Paolo Melchiorre
DOI:10.1002/anie.202111648
日期:2021.12.6
The first catalytic enantioselective conjugateaddition of allyl groups to α,β-unsaturated aldehydes is disclosed. The chemistry exploits the visible-light-excitation of chiral iminium ions to activate allyl silanes towards the formation of allylic radicals, which are then stereoselectively intercepted with high α-regioselectivity, complete chemoselectivity, and moderate to good enantioselectivity
Preparation of Allyl and Vinyl Silanes by the Palladium-Catalyzed Silylation of Terminal Olefins: A Silyl-Heck Reaction
作者:Jesse R. McAtee、Sara E. S. Martin、Derek T. Ahneman、Keywan A. Johnson、Donald A. Watson
DOI:10.1002/anie.201200060
日期:2012.4.10
high‐yielding protocol for the palladium‐catalyzed silylation of terminal alkenes is reported. This method allows facileconversion of styrenes to E‐β‐silyl styrenes by using iodotrimethylsilane (TMSI) or chlorotrimethylsilane/lithium iodide (see scheme). Terminal allyl silanes with good E/Z ratios are also readily accessed from α‐olefins.
A Pd-catalyzed oxidative silylation of simple olefins with hexamethyldisilane to give allylsilanes has been achieved usingmolecularoxygen as the sole oxidant. The reaction provides a useful protocol to access synthetically useful allylsilanes from easily accessible simple olefins and hexamethyldisilane without using any oxidants other than O2.
derivatives play pivotal roles across diverse applications, yet their current synthetic methods often entail intricate functional group manipulations. Despite the widespread use of allyl silanes as carbon nucleophiles in organic synthesis, their participation in allylic C–H functionalization has been underexplored. Herein, we unveil a metal-free intermolecular C–H amination of allyl silanes facilitated
A highly beta-selective C-allylation of 2,3-0-(3-pentylidene)-D-ribofuranosyl fluoride is described. This strategy will provide a new concept for synthesizing beta-C-ribosides by controlling the effect of steric hindrance in the transition state.