Design, synthesis and in vitro evaluation against human cancer cells of 5-methyl-5-styryl-2,5-dihydrofuran-2-ones, a new series of goniothalamin analogues
摘要:
The present work describes the preparation of a novel series of compounds based on the structure of goniothalamin (1), a natural styryl lactone with known cytotoxic and antiproliferative activities against a variety of cancer cell lines. A focused library of 17 goniothalamin analogues displaying the 5-methyl-2,5-dihydrofuran-2-one motif were prepared, and their cytotoxicity evaluated. While the analogues bearing methoxy and/or hydroxy groups on the aromatic moiety usually were at least three times less potent than the lead compound (1), ortho and para-trifluoromethyl analogues 10 and 11 exhibited levels of cytotoxicity similar to goniothalamin (1) against most cancer cell lines evaluated. One could suggest that the electronic effect of the trifluoromethyl group activates the inhibitor's electrophilic site via reduction of the electron density of the alpha,beta-unsaturated ester oxygen atom. These results provide new information on the structure activity relationship of these alpha,beta-unsaturated styryl lactones, thereby further focusing the design of novel candidates. (C) 2013 Elsevier Ltd. All rights reserved.
C–O cleavage via InIII alkoxide intermediates: In situ 13C NMR analysis of the mechanism of an enantioselective in-mediated cyclopropanation reaction
作者:Jennifer L. Slaughter、Guy C. Lloyd-Jones
DOI:10.1016/j.tet.2020.131786
日期:2021.1
dibenzylideneacetone and benzylideneacetone by in situ generated allyl indium reagents in the presence of methyl mandelate as a chiral modifier has been studied by in situ 13C1H} NMR in conjunction with 13C/2H labelling and mass spectrometry. Two indium alkoxides were identified, the first arising from indium mediated allylation of the ketone, the second arising from reaction of an in situ liberated
通过原位13 C 1 H} NMR结合13 C / 2 H标记和质量研究了原位生成的烯丙基铟在手性改性剂存在下通过原位生成的烯丙基铟试剂对二苄叉基丙酮和苄叉基丙酮进行不对称环丙烷化的机理。光谱法。鉴定出两种铟醇盐,第一种是由铟介导的酮的烯丙基化产生的,第二种是由LiI介导的原位释放的均烯丙基与过量的烯丙基铟试剂的反应产生的。在酸化过程中,氧的质子化导致C–O而不是In–O裂解,并且初始的叔烯丙基阳离子被约90%的si立体选择性烯丙基化 通过假定为扁桃酸酯螯合的铟烯丙基试剂进行选择性。
Generation of allyl Grignard reagents via titanocene-catalyzed activation of allyl halides
作者:Lauren M. Fleury、Brandon L. Ashfeld
DOI:10.1016/j.tetlet.2010.02.144
日期:2010.5
A protocol for the generation of allylGrignardreagents via the catalytic activation of allyl halides is described herein. Subsequent nucleophilic addition to carbonyl derivatives provided the desired homo allylic alcohols in excellent yields (84–99%). Evidence suggests that titanocene dichloride catalyzes the formation of an allylGrignard species which reacts solely with the carbonyl electrophile
mild catalytic allylation of carbonyl compounds, applicable to aldehydes, ketones, and imines is developed using allyltrimethoxysilane as the allylating reagent. The reaction proceeds smoothly with 1-10 mol % of CuCl and TBAT in THF at ambient temperature. Mechanism studies indicated that the copper alkoxide, allylfluorodimethoxysilane, and allyltrimethoxysilane are essential to promote the reaction
Cooperative Titanocene and Phosphine Catalysis: Accelerated C–X Activation for the Generation of Reactive Organometallics
作者:Lauren M. Fleury、Andrew D. Kosal、James T. Masters、Brandon L. Ashfeld
DOI:10.1021/jo301726v
日期:2013.1.18
transmetalation approach toward the generation of Grignard and organozinc reagents mediated by a titanocene catalyst. This method enables the metalation of functionalized substrates without loss of functional group compatibility. Allyl zinc reagents and allyl, vinyl, and alkyl Grignard reagents were generated in situ and used in the addition to carbonyl substrates to provide the corresponding carbinols in yields
Allylation of Unactivated Ketones by Tetraallyltin Accelerated by Phenol. Application to Asymmetric Allylation Using a Tetraallyltin-BINOL System
作者:Makoto Yasuda、Noriko Kitahara、Tatsuya Fujibayashi、Akio Baba
DOI:10.1246/cl.1998.743
日期:1998.8
The tetraallyltin-phenol system was mild and effective for allylation of unactivated ketones, giving tertiary alcohols in high yields. The asymmetric allylation was achieved by a tetraallyltin-homochiral BINOL (1,1′-bi-2-naphthol) system. The addition of methanol raised the enantioselectivity to afford the tertiary homoallylic alcohol up to 60% ee.