The formation of benzoxacin-3-ones <i>via</i> intramolecular Nicholas reactions and synthesis of 8-membered heliannuols
作者:Brent St. Onge、James R. Green
DOI:10.1039/d1ob01395e
日期:——
reactions to give dehydrobenzoxacin-3-one-Co2(CO)6 complexes in good yields. Reductive decomplexation and subsequent manipulation allows the synthesis of (±)-heliannuol K methyl ether and the formal syntheses of (±)-heliannuol K, (±)-heliannuol A, and (−)-heliannuol L.
由炔丙基醚-Co 2 (CO) 6配合物产生的 γ-羰基阳离子进行分子内尼古拉斯反应,以良好的收率得到 dehydrobenzoxacin-3-one-Co 2 (CO) 6配合物。还原解络和随后的操作允许合成 (±)-heliannuol K 甲基醚和 (±)-heliannuol K、(±)-heliannuol A 和 (-)-heliannuol L 的正式合成。
Iridium-Catalyzed Asymmetric Hydrogenation of Sterically Hindered Cyclic Imines for Enantioselective Synthesis of Tetrahydroisoquinolines
An efficient enantioselective hydrogenation of sterically hindered cyclic imines catalyzed by the Ir-tBu-ax-Josiphos complex has been described, producing a series of useful chiral bulky tetrahydroisoquinoline analogs in high isolated yields (85–96%) with good to excellent enantioselectivities (74–99% ee). This transformation provided highly straightforward access to the useful derivatives of tetrahydroisoquinolines
Pd(II)-Catalyzed <i>ortho</i>- or <i>meta</i>-C–H Olefination of Phenol Derivatives
作者:Hui-Xiong Dai、Gang Li、Xing-Guo Zhang、Antonia F. Stepan、Jin-Quan Yu
DOI:10.1021/ja400659s
日期:2013.5.22
A combination of weakly coordinating auxiliaries and ligand acceleration allows for the development of both ortho- and meta-selective C-H olefination of phenol derivatives. These reactions demonstrate the feasibility of directing C-H functionalizations when functional groups are distal to target C-H bonds. The meta-C-H functionalization of electron-rich phenol derivatives is unprecedented and orthogonal to previous electrophilic substitution of phenols in terms of regioselectivity. These methods are also applied to functionalize alpha-phenoxyacetic acids, a fibrate class of drug scaffolds.
Increasing Selectivity of CC Chemokine Receptor 8 Antagonists by Engineering Nondesolvation Related Interactions with the Intended and Off-Target Binding Sites
作者:Igor Shamovsky、Chris de Graaf、Lisa Alderin、Malena Bengtsson、Håkan Bladh、Lena Börjesson、Stephen Connolly、Hazel J. Dyke、Marco van den Heuvel、Henrik Johansson、Bo-Göran Josefsson、Anna Kristoffersson、Tero Linnanen、Annea Lisius、Roope Männikkö、Bo Nordén、Steve Price、Lena Ripa、Didier Rognan、Alexander Rosendahl、Marco Skrinjar、Klaus Urbahns
DOI:10.1021/jm900713y
日期:2009.12.10
The metabolic stability and selectivity of a series of CCR8 antagonists against binding to the hERG ion channel and cytochrome Cyp2D6 are studied by principal component analysis. It is demonstrated that an efficient way of increasing metabolic stability and selectivity of this series is to decrease compound lipophilicity by engineering nondesolvation related attractive interactions with CCR8, as rationalized by three-dimensional receptor models. Although Such polar interactions led to increased compound selectivity, such a strategy could also jeopardize the DMPK profile of compounds. However, once increased potency is found, the lipophilicity can be readjusted by engineering hydrophobic substituents that fit to CCR8 but do not fit to hERG. Several such lipophilic fragments are identified by two-dimensional fragment-based QSAR analysis. Electrophysiological measurements and site-directed mutagenesis studies indicated that the repulsive interactions of these fragments with hERG are caused by steric hindrances with residue F656.