The development of methods to allow the selective acylative dynamic kinetic resolution (DKR) of tetra‐substituted lactols is a recognised synthetic challenge. In this manuscript, a highly enantioselective isothiourea‐catalysed acylative DKR of tetra‐substituted morpholinone and benzoxazinone‐derived lactols is reported. The scope and limitations of this methodology have been developed, with high enantioselectivity and good to excellent yields (up to 89%, 99:1 er) observed across a broad range of substrate derivatives incorporating substitution at N(4) and C(2), di‐ and spirocyclic substitution at C(5)‐ and C(6)‐position, as well as benzannulation (>35 examples in total). The DKR process is amenable to scale‐up on a 1 g laboratory scale. The factors leading to high selectivity in this DKR process have been probed through computation, with an N‐C=O•••isothiouronium interaction identified as key to producing ester products in highly enantioenriched form.
Design, Synthesis, and Biological Activity of New N-(Phenylmethyl)-benzoxazol-2-thiones as Macrophage Migration Inhibitory Factor (MIF) Antagonists: Efficacies in Experimental Pulmonary Hypertension
摘要:
Macrophage migration inhibitory factor (MIF) is a key pleiotropic mediator and a promising therapeutic target in cancer as well as in several inflammatory and cardiovascular diseases including pulmonary arterial hypertension (PAH). Here, a novel series of N-(phenylmethyl)-benzoxazol-2-thiones 5-32 designed to target the MIF tautomerase active site was synthesized and evaluated for its effects on cell survival. Investigation of structure-activity relationship (SAR) particularly at the 5-position of the benzoxazole core led to the identification of 31 that potently inhibits cell survival in DU-145 prostate cancer cells and pulmonary endothelial cells derived from patients with idiopathic PAH (iPAH-ECs), two cell lines for which survival is MIF-dependent. Molecular docking studies helped to interpret initial SAR related to MIF tautomerase inhibition and propose preferred binding mode for 31 within the MIF tautomerase active site. Interestingly, daily treatment with 31 started 2 weeks after a subcutaneous monocrotaline injection regressed established pulmonary hypertension in rats.
Enantioselective Copper-Catalyzed Formal [4 + 2] Cycloaddition of <i>o</i>-Aminophenol Derivatives with Propargylic Esters for Synthesis of Optically Active 3,4-Dihydro-2<i>H</i>-1,4-benzoxazines
作者:Zhen-Ting Liu、Ya-Hui Wang、Fu-Lin Zhu、Xiang-Ping Hu
DOI:10.1021/acs.orglett.6b00322
日期:2016.3.4
The first copper-catalyzed asymmetric formal [4 + 2] cycloaddition of o-aminophenol derivatives with propargylic esters as the bis-electrophilic C2 synthons for the stereoselective construction of chiral 2,3,4-trisubstituted 2H-1,4-benzoxazines bearing an exocyclic double bond has been developed. By using a structurally modified chiralketimineP,N,N-ligand, a wide range of optically active 2H-1,4-benzoxazines
首次铜催化邻氨基苯酚衍生物与炔丙酸酯作为双亲电子C2合成子的不对称[4 + 2]环加成,用于立体选择性地构建手性2,3,4-三取代的2 H -1,4-苯并恶嗪轴承已经开发了环外双键。通过使用结构改性的手性酮亚胺P,N,N-配体,可以高收率和极好的对映选择性(高达97%ee)制备各种光学活性的2 H -1,4-苯并恶嗪。
One‐Pot Cascade Transformation of Glucal into Structurally Diverse Drug‐Like Scaffolds
作者:Hui Yao、Ronny Willam、Siming Wang、Jingxi He、Tai Guo、Xue‐Wei Liu
DOI:10.1002/asia.201900844
日期:2019.11.18
A diversity-oriented synthesis strategy to produce threetypes of structurally drug-like N-heterocyclic-fused rings has been developed from abundant biomass-derived d-glucal, aniline and water in a stereoselective manner. The overall transformation which entails a cascade of Ferrier reaction and 4π conrotatory imino-Nazarov cyclization was performed in one-pot allowing convenient preparation of scaffolds