Nonpeptide Urotensin-II Receptor Antagonists: A New Ligand Class Based on Piperazino-Phthalimide and Piperazino-Isoindolinone Subunits
摘要:
We have discovered two related chemical series of nonpeptide urotensin-II (U-II) receptor antagonists based oil piperazino-phthalimide (5 and 6) and piperazino-isoindolinone (7) scaffolds. These structure types are distinctive from those of U-II receptor antagonist series reported in the literature. Antagonist 7a exhibited single-digit nanomolar potency in rat and human cell-based functional assays, as well as strong binding to the human U-II receptor. In advanced pharmacological testing, 7a blocked the effects of U-II in vitro in a rat aortic ring assay and in vivo in it rat ear-flush model. A discussion of U-II receptor antagonist pharmacophores is presented, and it specifically defined model is suggested from tricycle 13, which has it high degree of conformational constraint.
Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetrichydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.
Rhodium-Catalyzed Asymmetric Transfer Hydrogenation of Aryl Alkyl Ketones Employing Ligands Derived from Amino Acids
作者:Jenny Wettergren、Alexey B. Zaitsev、Hans Adolfsson
DOI:10.1002/adsc.200700345
日期:2007.12.10
The combination of (pentamethylcyclopentadienyl)rhodium dichloride dimer [RhCl2Cp*}2] and pseudodipeptide ligands, formed from N-Boc protected amino acids and amino alcohols, resulted in efficient and selective catalysts for the asymmetric transfer hydrogenation of ketones in 2-propanol. A number of different secondary alcohols was obtained in high yields and in excellent enantioselectivity using
The synthesis of a new paracyclophane phosphine is described. This ligand was highly efficient in the ruthenium-catalyzed asymmetric hydrogenation of various aromatic and heteroaromatic ketones.
描述了一种新的对环烷膦的合成。该配体在钌催化的各种芳族和杂芳族酮的不对称氢化中非常有效。
Practical and Efficient Procedure for the In Situ Preparation of B-Alkoxyoxazaborolidines. Enantioselective Reduction of Prochiral Ketones
作者:Viviana Ponzo、Teodoro Kaufman
DOI:10.3390/50300495
日期:——
A new method for the in situ elaboration of B-alkoxyoxazaborolidines is presented. Their use in the enantioselective reduction of prochiral aromatic ketones provides excellent chemical and optical yields of chiral alcohols.
preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetrichydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes usecatalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium
手性分子(如醇)对于精细化学品、药物、农用化学品、香料和新型材料的制造至关重要。这些分子需要以高产率和高光学纯度并优先催化生产。在所有的不对称催化反应中,工业上应用最广泛的是与H2(AH)的不对称加氢反应。除了少数例外,这些 AH 工艺使用基于三种关键金属(铑、钌和铱)的催化剂。在本文中,我们描述了一种简单的、工业上可行的铁催化剂,它允许酮的 AH,目前该过程主要由钌和铑催化剂主导。通过将手性 22 元大环配体与廉价、易得的 Fe3(CO)12 结合,多种酮在 50 bar H2 和 45-65 °C 下氢化,提供了非常有价值的手性醇,其对映选择性接近或超过用贵金属催化剂获得的那些。与大多数贵金属催化剂的 AH 相比,铁催化的氢化似乎是非均相的。