Optimization of α-Ketooxazole Inhibitors of Fatty Acid Amide Hydrolase
作者:F. Scott Kimball、F. Anthony Romero、Cyrine Ezzili、Joie Garfunkle、Thomas J. Rayl、Dustin G. Hochstatter、Inkyu Hwang、Dale L. Boger
DOI:10.1021/jm701210y
日期:2008.2.1
A series of alpha-ketooxazoles containing conformational constraints in the flexible C2 acyl side chain of 2 (OL-135) and representative oxazole C5 substituents were prepared and examined as inhibitors of fatty acid amide hydrolase (FAAH). Exceptionally potent and selective FAAH inhibitors emerged from the series (e.g., 6, K-i = 200 and 260 pM for rat and rhFAAH). With simple and small C5 oxazole substituents, each series bearing a biphenylethyl, phenoxyphenethyl, or (phenoxymethyl)phenethyl C2 side chain was found to follow a well-defined linear relationship between -log K-i and Hammett sigma(p) of a magnitude (rho = 2.7-3.0) that indicates that the substituent electronic effect dominates, confirming its fundamental importance to the series and further establishing its predictive value. Just as significantly, the nature of the C5 oxazole substituent substantially impacts the selectivity of the inhibitors whereas the effect of the C2 acyl chain was more subtle but still significant even in the small series examined. Combination of these independent features, which display generalized trends across a range of inhibitor series, simultaneously improves FAAH potency and selectivity and can provide exquisitely selective and potent FAAH inhibitors.
The Reversible Nicholas Reaction in the Synthesis of Highly Symmetric Natural-Product-Based Macrocycles
作者:María C. de la Torre、María Asenjo、Pedro Ramírez-López、Miguel A. Sierra
DOI:10.1002/ejoc.201403541
日期:2015.2
Two different approaches to highlysymmetricmacrocycles by reversibleNicholasreactions have been developed. The first sequence uses a bis[Co2(CO)6] complex derived from a double propargylic alcohol supporting two natural product moieties. The reactions with BF3·OEt2 and different benzene dimethanols yielded either (1:1) or (2:2) adducts, depending essentially on the nature of the tether joining
通过可逆尼古拉斯反应开发了两种不同的高度对称大环方法。第一个序列使用衍生自支持两个天然产物部分的双炔丙醇的双 [Co2(CO)6] 复合物。与 BF3·OEt2 和不同苯二甲醇的反应产生 (1:1) 或 (2:2) 加合物,这主要取决于连接两个 Co 簇的系链的性质。或者,与一个类固醇和一个单萜片段以及一个含有醇部分的芳族末端共络合的炔丙醇模板的 Nicholas 反应产生了源自自二聚化的相应大环。两条通往大环的路线是互补的,可以有效地产生复杂的含有天然产物的结构。