Development of an O-Vinylation–Ring-Closing Metathesis Strategy to Access 3,3′-3,4-Dihydropyrans
作者:Anne-Marie Dechert-Schmitt、Shawn Cabral、Daniel Kung
DOI:10.1055/s-0036-1588615
日期:——
Dihydropyrans are common structural motifs that appear in both natural products and pharmaceuticals and are intermediates for the synthesis of tetrahydropyrans. Currently, no reports exist in the literature for the synthesis of 3,3′-differentially disubstituted-3,4-dihydro-2-pyrans. We describe an approach employing abundant esters as starting materials that allows access to these heterocyclic scaffolds
Visible‐Light Photoredox‐Catalyzed α‐Regioselective Conjugate Addition of Allyl Groups to Activated Alkenes
作者:Arjun Gontala、Sang Kook Woo
DOI:10.1002/adsc.202000445
日期:2020.8.4
The α‐regioselective conjugate addition of allyl groups to activated alkenes is a poorly explored area of research. Herein, we report an α‐adduct and (E )‐isomer selective conjugate addition of allylsilanes to activated alkenes by visible‐light photoredox catalysis. The reaction involves allylic radicals that can be generated from allylsilanes through a photoinduced single‐electron transfer mechanism
Dynamic Kinetic Resolution of Aldehydes by Hydroacylation
作者:Zhiwei Chen、Yusuke Aota、Hillary M. H. Nguyen、Vy M. Dong
DOI:10.1002/anie.201900545
日期:2019.3.26
We report a dynamickineticresolution (DKR) of chiral 4‐pentenals by olefin hydroacylation. A primary amine racemizes the aldehyde substrate via enamine formation and hydrolysis. Then, a cationic rhodium catalyst promotes hydroacylation to generate α,γ‐disubstituted cyclopentanones with high enantio‐ and diastereoselectivities.
Isomerization of Olefins Triggered by Rhodium-Catalyzed CH Bond Activation: Control of Endocyclic β-Hydrogen Elimination
作者:Stephanie Y. Y. Yip、Christophe Aïssa
DOI:10.1002/anie.201500596
日期:2015.6.1
Five‐membered metallacycles are typically reluctant to undergo endocyclic β‐hydrogen elimination. The rhodium‐catalyzed isomerization of 4‐pentenals into 3‐pentenals occurs through this elementary step and cleavage of two CH bonds, as supported by deuterium‐labeling studies. The reaction proceeds without decarbonylation, leads to trans olefins exclusively, and tolerates other olefins normally prone
Disclosed is a compound having the formula:
pharmaceutically acceptable salts or solvates thereof and pharmaceutical compositions containing the same, wherein the structural variables are as defined herein. The compounds, salts and solvates of this invention are useful as LXR agonists.