16205-90-6Relevant academic research and scientific papers
One-pot mild and efficient synthesis of [1,3]thiazino[3,2-: A] indol-4-ones and their anti-proliferative activity
Rhodes, Steven,Short, Spencer,Sharma, Sidhika,Kaur, Ramneet,Jha, Mukund
, p. 3914 - 3920 (2019)
A base mediated environmentally benign one-pot efficient methodology has been developed for the synthesis of [1,3]thiazino[3,2-a]indol-4-ones using indoline-2-thiones and propiolate esters in aqueous medium. The conjugate addition of thiones first results in ethyl (3-(indol-2-yl)thio)acrylates in situ, which subsequently undergoes intramolecular cyclization to produce indole-fused thiazin-4-ones in good to excellent yields. The cytotoxic screening of the synthesized compounds using MTT assay revealed the anti-proliferative nature of these frameworks against triple negative breast cancer cell lines with the highest activity emanating from 4H-[1,3]thiazino[3,2-a]indol-4-one and 8-methyl-2-propyl-4H-[1,3]thiazino[3,2-a]indol-4-one compounds.
Selective one-pot synthesis of allenyl and alkynyl esters from β-ketoesters
Maity, Pradip,Lepore, Salvatore D.
, p. 158 - 162 (2009)
(Chemical Equation Presented) A convenient method is described for the dehydration of β-ketoesters to generate conjugated and deconjugated alkynyl esters and conjugated allenyl esters. This sequential one-pot method involves the formation of a vinyl trifl
Coumarins by Direct Annulation: β-Borylacrylates as Ambiphilic C3-Synthons
Wienhold, Max,Molloy, John J.,Daniliuc, Constantin G.,Gilmour, Ryan
supporting information, p. 685 - 689 (2020/11/30)
Modular β-borylacrylates have been validated as programmable, ambiphilic C3-synthons in the cascade annulation of 2-halo-phenol derivatives to generate structurally and electronically diverse coumarins. Key to this [3+3] disconnection is the BPin unit which serves a dual purpose as both a traceless linker for C(sp2)–C(sp2) coupling, and as a chromophore extension to enable inversion of the alkene geometry via selective energy transfer catalysis. Mild isomerisation is a pre-condition to access 3-substituted coumarins and provides a handle for divergence. The method is showcased in the synthesis of representative natural products that contain this venerable chemotype. Facile entry into π-expanded estrone derivatives modified at the A-ring is disclosed to demonstrate the potential of the method in bioassay development or in drug repurposing.
Z-Selective phosphine promoted 1,4-reduction of ynoates and propynoic amides in the presence of water
Drikermann, Denis,Kupfer, Stephan,Seifert, Fabian,Steinmetzer, Johannes,Vilotijevic, Ivan,Zi, You
supporting information, p. 6092 - 6097 (2021/07/21)
Phosphine-mediated reductions of substituted propynoic esters and amides in the presence of water yield the partially reduced α,β-unsaturated esters and amides with highZ-selectivity. The competitivein situ ZtoE-isomerization of the product in some cases lowers theZtoEratios of the isolated α,β-unsaturated carbonyl products. Reaction time and the amounts of phosphine and water in the reaction mixture are the key experimental factors which control the selectivity by preventing or reducing the rates ofZ- toE-product isomerization. Close reaction monitoring enables isolation of theZ-alkenes with high selectivities. The computational results suggest that the reactions could be highlyZ-selective owing to the stereoselective formation of theE-P-hydroxyphosphorane intermediate.
Phosphine-Catalyzed Intermolecular Dienylation of Alkynoate with para-Quinone Methides
Song, Zefeng,Wang, Weijia,Liu, Zhixin,Lu, Yue,Wang, De
supporting information, p. 8590 - 8599 (2021/07/20)
An interesting remote I-C 1,6-Addition and an isomerization cascade reaction for phosphine-catalyzed activated alkynes have been disclosed. The products featuring a functional diene and a 1,1-diaryl methyl motif have been obtained in moderate to good yields (30-86%) by applying para-quinone methides (p-QMs) and I-substituted alkynoate with tributylphosphine (PnBu3) catalysis, along with high regioselectivity and stereoselectivity (dr > 20:1). The wide scope of compatible substrates (35 examples), such as indolyl, oxindolyl, ester, and cinnamyl, expand the utility of this methodology. A plausible mechanism and some applications of it have also been presented.
Trans -Hydroboration vs. 1,2-reduction: Divergent reactivity of ynones and ynoates in Lewis-base-catalyzed reactions with pinacolborane
Zi, You,Sch?mberg, Fritz,Seifert, Fabian,G?rls, Helmar,Vilotijevic, Ivan
supporting information, p. 6341 - 6349 (2018/09/10)
Ynones and ynoates react with pinacolborane in a divergent manner in the presence of nucleophilic phosphine catalysts. Ynones are transformed to the corresponding propargyl alcohols in good yields with high regio- and chemoselectivity. Ynoates undergo highly regio- and stereoselective trans-hydroboration to produce E-vinylboronates. Impressive divergence in reactivity of ynones and ynoates can be traced back to the mechanistic aspects of 1,2-reduction and trans-hydroboration. A comparative analysis of the two pathways paints a complex picture in which different reaction rates control selectivity in these seemingly unrelated processes and explains how sufficiently acidic protons in the reaction mixtures can be used to steer the selectivity in different directions.
Copper(II)-catalyzed silylation of activated alkynes in water: Diastereodivergent access to E- or Z-β-silyl-α,β-unsaturated carbonyl and carboxyl compounds
Calderone, Joseph A.,Santos, Webster L.
supporting information, p. 4154 - 4158 (2014/05/06)
Copper(II)-catalyzed silylation of substituted alkynylcarbonyl compounds was investigated. Through the activation of Me2PhSiBpin in water at room temperature and open atmosphere, vinylsilanes conjugated to carbonyl groups are synthesized in high yield. A surprising diastereodivergent access to olefin geometry was discovered using a silyl conjugate addition strategy: aldehydes and ketones were Z selective while esters and amides were exclusively transformed into the E products. Dial a diastereomer: The title reaction proceeds through the activation of Me2PhSiBpin in water at room temperature and open atmosphere to produce high yields of vinylsilanes conjugated to carbonyl groups. A surprising diastereodivergent access to olefin geometry was discovered using this silyl conjugate addition strategy: aldehydes were Z selective while esters and amides exclusively delivered the E-configured products.
An efficient, overall [4+1] cycloadditon of 1,3-dienes and nitrene precursors
Wu, Qiong,Hu, Jian,Ren, Xinfeng,Zhou, Jianrong
supporting information; experimental part, p. 11553 - 11558 (2011/11/29)
Intermolecular cycloadditions of conjugated dienes and nitrene precursors usually produce aziridines. A generally useful method was lacking to directly provide the [4+1] cycloadducts, 3-pyrrolines. We have realized this transformation by using an uniquely active catalyst, copper(II) 1,1,1,5,5,5-hexafluoroacetylacetonate ([Cu(hfacac)2]). The method is applicable to a wide array of dienes with good yields. When 1,4-disubsituted dienes are used as substrates, good-to-excellent cis or trans selectivity can be obtained. Interestingly, the cis or trans preference depends on the nature of the substituents, rather than diene geometry. Mechanistic studies reveal that the [4+1] cycloaddition proceeds through diene aziridination and subsequent ring expansion. Among common copper catalysts, only [Cu(hfacac)2] can efficiently catalyze both steps, which explains the unique efficiency of the catalyst.
Photooxidation of Strained Olefins. 4. Cyclopropenes
Frimer, Aryeh A.,Antebi, Abraham
, p. 2334 - 2340 (2007/10/02)
The photosensitized oxidation of cyclopropenes 5a-c proceeds rapidly, producing a plethora of products whose formation can be understood in terms of secondary rearrangements of initially formed products hydroperoxide 24 and epoxide 29.However, the reaction does not involve singlet oxygen but is rather a free-radical process.
