Divergent Strategy for the Diastereoselective Synthesis of the Tricyclic 6,7-Diaryltetrahydro-6<i>H</i>-benzo[<i>c</i>]chromene Core via Pt(IV)-Catalyzed Cycloaddition of <i>o</i>-Quinone Methides and Olefin Ring-Closing Metathesis
A divergent strategy for the synthesis of the tricyclic 6,7-diaryltetrahydro-6H-benzo[c]chromene core was successfully developed. The 2,3-trans, 2,4-cis trisubstituted chroman moiety was formed via highly efficient and stereoselective Pt(IV)-catalyzed cycloadditionreactions of the corresponding quinone methides with chalcones. Subsequent steps provided the common diene alcohol, which underwent BF3·Et2O-mediated
成功开发了一种合成三环6,7-二芳基四氢-6 H-苯并[ c ]色烯核心的不同策略。2,3-反式,2,4-顺式三取代的苯并二氢吡喃部分是通过相应的醌甲基化物与查耳酮的高效且立体选择性的Pt(IV)催化的环加成反应形成的。随后的步骤提供了普通的二烯醇,其经过BF 3 ·Et 2 O介导的Et 3 SiH还原和使用Ru(II)催化剂进行的烯烃闭环复分解(RCM)。最后两个步骤的顺序为使C6和C10a处的立体化学结果多样化提供了一种方法。
Synthesis and in vitro antitumor activity of new 4,5-dihydropyrazole derivatives
A series of 3,5-diaryl-4,5-dihydropyrazole regioisomers, and their 1-acetylated derivatives, bearing a 3,4,5-trimethoxyphenyl moiety combined with a variety of substituted phenyl rings, was synthesized and evaluated for antitumor activity. Results of the in vitro assay against a non-small cell lung carcinoma cell line (NCI-H460) showed several compounds to be endowed with cytotoxicity in micromolar to sub-micromolar range, depending on substitution pattern and position of aryl rings on 4,5-dihydropyrazole core. Potent and selective activity was also observed in the NCI 60 human cancer cell line panel. 5-(3,4,5-Trimethoxyphenyl) pyrazolines 31 and 39 were found to possess potent antiproliferative activity against SR and MDA-MB-435, with GI(50) inhibitory values in nanomolar range. Structure-activity relationships revealed that introduction of a (hydroxy) acetyl group at N-1 of inactive 5-(3,4,5-trimethoxyphenyl) pyrazolines, results in a clear in vitro activating effect. Compound 31 (IC(50) = 5.16 mu M) showed inhibition of tubulin polymerization comparable to that of CA-4 (IC(50) = 4.92 mu M). (C) 2010 Elsevier Ltd. All rights reserved.