Acyl-CoA: cholesterol O-acyl transferase (ACAT) inhibitors. 1. 2-(Alkylthio)-4,5-diphenyl-1H-imidazoles as potent inhibitors of ACAT
作者:Neil V. Harris、Andrew W. Bridge、Raymond C. Bush、Edward C. J. Coffee、Donald I. Dron、Mark F. Harper、Michael J. Ashton、David J. Lythgoe、Christopher Smith
DOI:10.1021/jm00101a016
日期:1992.11
potent, bioavailable ACAT inhibitor may have beneficial effects in the treatment of atherosclerosis by (i) reducing the absorption of dietary cholesterol, (ii) reducing the secretion of very low density lipoproteins into plasma from the liver, and (iii) preventing the transformation of arterial macrophages into foam cells. We have found that a mevalonate derivative 2, which contains a 4,5-diphenyl-1H-imidazol-2-yl
Pushing Radical Cyclization from Regioselective to Regiospecific: Cyclization of Amidyl Radicals Controlled by Vinylic Halogen Substitution
作者:Tianshun Hu、Meihua Shen、Qian Chen、Chaozhong Li
DOI:10.1021/ol060983q
日期:2006.6.1
be accomplished by the direct reactions of unsaturated N-H amides if they bear a vinylic halogen (Cl, Br, I) substituent. This remarkable halogen-substitution effect could be rationalized in terms of lone pair-lone pairelectron repulsion between the N radical and the vinylic halogen atom, in addition to the well-known steric and radical-stabilizing effect. [reaction: see text]
The halogen-bonding interaction between I2 and N-iodosuccinimide (NIS) stabilized by a Lewis base (LB) has been explored. 1H NMR, nuclear Overhauser effect (NOE), and diffusion-ordered NMR spectroscopy (DOSY) suggest the generation of a 1:1:1 assembly, LB–I2–NIS. In contrast, when N-iodotrifluoromethanesulfonimide (INTf2) is used instead of NIS, LB–I5+–LB is generated. On the basis of these results
Unsaturatedacids and alcohols interact with Oxone® and KI in acetonitrile-H 2 O and undergo iodolactonization and iodoetherification in short times with good yields. The reaction has been used for the formal synthesis ofmintlactone starting from isopulegol.
不饱和酸和醇在乙腈-H 2 O 中与 Oxone® 和 KI 相互作用,并在短时间内以良好的产率进行碘内酯化和碘醚化。该反应已用于从异胡薄荷醇开始正式合成薄荷内酯。
Achiral Counterion Control of Enantioselectivity in a Brønsted Acid-Catalyzed Iodolactonization
作者:Mark C. Dobish、Jeffrey N. Johnston
DOI:10.1021/ja301858r
日期:2012.4.11
Highly enantioselective halolactonizations have been developed that employ a chiral proton catalyst-N-iodosuccinimide (NIS) reagent system in which the Brønsted acid is used at catalyst loadings as low as 1 mol %. An approach that modulates the achiral counterion (equimolar to the neutral chiral ligand-proton complex present at low catalyst loadings) to optimize the enantioselection is documented for