- Organocatalytic enantioselective 1,3-dipolar cycloadditions between seyferth-gilbert reagent and isatylidene malononitriles: Synthesis of chiral spiro-phosphonylpyrazoline-oxindoles
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A new method has been developed for the catalytic enantioselective 1,3-dipolar cycloaddition of the Seyferth-Gilbert reagent (SGR) to isatylidene malononitriles using a cinchona alkaloid derivative as a catalyst. This method allowed for the synthesis of a series of chiral spiro-phosphonylpyrazoline-oxindoles in good yields with excellent enantioselectivities. The synthetic utility of this method was further demonstrated by its use in a three-component domino reaction involving isatin, malononitrile, and SGR based on sequential Knoevenagel condensation and 1,3-dipolar cycloaddition reactions.
- Du, Taiping,Du, Fei,Ning, Yanqiang,Peng, Yungui
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Read Online
- A Convenient Procedure for the Synthesis of 2,2,2-Trifluoroethyl Methyl 2-Oxoalkylphosphonates
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(Figure Presented) A convenient and versatile method was developed for the synthesis of 2,2,2-trifluoroethyl methyl 2-oxoalkylphosphonates starting from dimethyl phosphonates by alkaline hydrolysis followed by esterification with 2,2,2-trifluoroethanol using diisopropylcarbodiimide (DIC) in the presence of 4-(dimethylamino)pyridine (DMAP) catalyst following the Steglich protocol.
- Molnár, Katalin,Behra, Julien,Takács, László,Kádár, Mihály,Kardos, Zsuzsanna,Faigl, Ferenc
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Read Online
- Structure-Elucidating Total Synthesis of the (Polyenoyl)tetramic Acid Militarinone C §
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The (polyenoyl)tetramic acid militarinone C (1) heads a family of seven members. Before our work, the configuration of C-5 was unknown whereas the configurations of C-8′ and C-10′ were either (R,R) or (S,S). We synthesized the four stereoisomers of constitution 1, which conform with these insights. This included cross-coupling both enantiomers of the western building block (8) with both enantiomers of the eastern building block (9). The specific rotations of the resulting 1 isomers suggested that natural 1 is configured like the coupling partners (S)-8 and (R,R)-9. This conclusion was corroborated by degrading natural 1 to alcohol 35 and by proving its configurational identity with synthetic (R,R)-35.
- Brückner, Reinhard,Drescher, Christian,Hamburger, Matthias,Keller, Morris,Potterat, Olivier
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supporting information
(2020/03/30)
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- Alkyl phosphonate preparing method
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The invention provides an alkyl phosphonate preparing method. The method comprises: performing an Arbuzov reaction on compound A and compound B in a continuous reaction apparatus, and continuously discharging the product obtained from the reaction from the continuous reaction apparatus during the reaction procedure, to obtain alkyl phosphonate. The reaction temperature in the reaction procedure is T1; either of compound A and compound B having a lower boiling point has a boiling point at a standard atmosphere pressure to be T2; T1 is higher than T2 by 10-40 DEG C; and the reaction pressure in the reaction procedure is 0.5-2.0 MPa. The preparing method in the invention may use halohydrocarbon having large steric hindrance and lower polarizability of carbon-halogen bond as compound A, thereby effectively expanding a selection range of substrate, and correspondingly expanding the types of alkyl phosphonate prepared by using the Arbuzov reaction.
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Paragraph 0076; 0077; 0078
(2017/10/07)
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- A tunable copper-catalyzed multicomponent reaction towards alkaloid-inspired indole/lactam polycycles
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A versatile copper(i)-catalyzed cascade multicomponent reaction strategy between readily available (Z)-3-iodoacrylic acids, terminal alkynes, and primary amines is reported, leading to a great diversity of complex heterocyclic backbones based on biorelevant indole/lactam scaffolds.
- Mardjan,Perie,Parrain,Commeiras
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supporting information
p. 3304 - 3309
(2017/04/21)
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- REMOVAL OF SENESCENCE-ASSOCIATED MACROPHAGES
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In various aspects and embodiments provided are compounds, compositions and methods relating to aging, senescent cells (SCs) and/or senescence associate macrophages (SAMs). In certain aspects and embodiments provided are compounds and compositions that selectively kill or reprogram senescent cells (SCs) and or senescence associate macrophages (SAMs) and associated methods. In some embodiments, the compounds compositions and methods treat or reverse aging and/or age-related diseases.
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Paragraph 0295; 0296
(2017/12/15)
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- Silver-Catalyzed Oxidative C(sp3)?P Bond Formation through C?C and P?H Bond Cleavage
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The silver-catalyzed oxidative C(sp3)?H/P?H cross-coupling of 1,3-dicarbonyl compounds with H-phosphonates, followed by a chemo- and regioselective C(sp3)?C(CO) bond-cleavage step, provided heavily functionalized β-ketophosphonates. This novel method based on a readily available reaction system exhibits wide scope, high functional-group tolerance, and exclusive selectivity.
- Li, Lili,Huang, Wenbin,Chen, Lijin,Dong, Jiaxing,Ma, Xuebing,Peng, Yungui
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supporting information
p. 10539 - 10544
(2017/08/22)
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- Synthesis of 1,2,3-triazoles from azide-derivatised aminocyclitols by catalytic diazo transfer and CuAAC click chemistry
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CuII-catalysed diazo transfer and CuI-catalysed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) "click chemistry" were used to synthesis C7N aminocyclitol-derivatised 1,2,3-triazoles. In the course of this work, the -N=N- moiety was transferred onto C7N aminocyclitols such as validamine, valienamine and valiolamine by employing imidazole-1-sulfonyl azide as the diazo transfer reagent with catalysis by CuII, ZnII and NiII, in moderate to good yields. The obtained azidocyclitols were coupled with various terminal alkynes under modified Meldal's conditions with good to excellent yields. The stereo- and regiochemistry of the products were confirmed by 2D-NMR (NOESY and HMBC). One-pot syntheses of the corresponding 1,2,3-triazoles, as safer and more efficient procedures, were also investigated and gave moderate to good yields. Copyright
- Ji, Li,Zhou, Guo-Quan,Qian, Chao,Chen, Xin-Zhi
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supporting information
p. 3622 - 3636
(2014/06/23)
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- Semi-synthesis of biologically active nisin hybrids composed of the native lanthionine ABC-fragment and a cross-stapled synthetic DE-fragment
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The antimicrobial peptide nisin is a promising template for designing novel peptide-based antibiotics to improve its drug-like properties. First steps in that direction represent the synthesis of hybrid nisin derivatives that contain a native nisin ABC-part and synthesized cross-stapled DE-ring fragments and are described here. The biological activity of the newly synthesized nisin derivatives was evaluated in order to compare the bioactivity of the synthetic DE-ring containing mimic and native lanthionine-bridged DE-ring containing nisin. The native nisin ABC-ring system was obtained via chymotrypsin digestion of full-length nisin, and was subsequently functionalized at the C-terminal carboxylate with two different amino alkyne moieties. Next, nisin hybrids were successfully prepared using Cu(I)-catalyzed azide alkyne cycloaddition 'click' chemistry by chemo-selective ligation of the ABC-alkyne with the N-terminal azido functionalized dicarba-DE ring mimic. The newly synthesized compounds were active as potent lipid II binders and retained antimicrobial activity in a growth inhibition assay. However, pore formation was not observed, possibly either due to the different character of the 'staples' as compared to the parent sulfides, or due to the triazole moiety as a sub-optimal amide bond isostere.
- Slootweg, Jack C.,Peters, Nienke,Quarles Van Ufford,Breukink, Eefjan,Liskamp, Rob M.J.,Rijkers, Dirk T.S.
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supporting information
p. 5345 - 5353
(2014/12/11)
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- Synthesis and antiviral evaluation of 4′-(1,2,3-triazol-1-yl) thymidines
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Non-obligate chain terminating nucleosides with a linear substituent (azido or ethynyl group) at the 4′ position represent an important class of compounds in antiviral discovery, particularly against hepatitis C virus (HCV) and human immunodeficiency virus (HIV). We have previously shown that 3′-azidothymidine (AZT)-derived 1,2,3-triazoles can be potent inhibitors of HIV-1. To gauge the medicinal chemistry impact of functionalizing the 4′-linear substituent and possibly generate novel antiviral nucleoside scaffolds, we have explored azide-alkyne cycloaddition reactions with 4′-azidothymidine (ADRT). The Ru-mediated reaction failed and the Cu-catalyzed variant generated 1,2,3-triazoles (9a-y) with only modest yields and efficiencies, indicating a substantial steric barrier around the 4′-azido group. Antiviral screening identified a few triazole analogues moderately active against HIV-1 (18-62% inhibition at 10 μM) and/or influenza A virus (15-50% inhibition at 10 μM), and none active against West Nile virus (WNV) or HCV. These results suggest that the linear 4′ azido group of ADRT may be essential for target binding and that its chemical manipulation could largely compromise antiviral potency. This journal is the Partner Organisations 2014.
- Vernekar, Sanjeev Kumar V.,Qiu, Li,Zacharias, Jeana,Geraghty, Robert J.,Wang, Zhengqiang
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supporting information
p. 603 - 608
(2014/05/06)
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- Diastereo- and enantioselective asymmetric hydrogenation of α-amido-β-keto phosphonates via dynamic kinetic resolution
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Dynamic kinetic resolution of various α-amido-β-keto phosphonates via asymmetric hydrogenation proceeded efficiently to give the corresponding β-hydroxy-α-amido phosphonates in high diastereo- and enantioselectivities (up to 99:1 syn/anti, 99.8% ee). The addition of catalytic amounts of CeCl3 3 7H2O is necessary to achieve both good selectivity and catalytic efficiency under mild reaction conditions.
- Tao, Xiaoming,Li, Wanfang,Li, Xiaoming,Xie, Xiaomin,Zhang, Zhaoguo
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supporting information
p. 72 - 75
(2013/03/28)
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- Clicking 3′-azidothymidine into novel potent inhibitors of human immunodeficiency virus
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3′-Azidothymidine (AZT) was the first approved antiviral for the treatment of human immunodeficiency virus (HIV). Reported efforts in clicking the 3′-azido group of AZT have not yielded 1,2,3-triazoles active against HIV or any other viruses. We report herein the first AZT-derived 1,2,3-triazoles with submicromolar potencies against HIV-1. The observed antiviral activities from the cytopathic effect (CPE) based assay were confirmed through a single replication cycle assay. Structure-activity-relationship (SAR) studies revealed two structural features key to antiviral activity: a bulky aromatic ring and the 1,5-substitution pattern on the triazole. Biochemical analysis of the corresponding triphosphates showed lower ATP-mediated nucleotide excision efficiency compared to AZT, which along with molecular modeling suggests a mechanism of preferred translocation of triazoles into the P-site of HIV reverse transcriptase (RT). This mechanism is corroborated with the observed reduction of fold resistance of the triazole analogue to an AZT-resistant HIV variant (9-fold compared to 56-fold with AZT).
- Sirivolu, Venkata Ramana,Vernekar, Sanjeev Kumar V.,Ilina, Tatiana,Myshakina, Nataliya S.,Parniak, Michael A.,Wang, Zhengqiang
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supporting information
p. 8765 - 8780
(2013/12/04)
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- A highly convergent cascade cyclization to cis-hydrindanes with all-carbon quaternary centers and its application in the synthesis of the aglycon of dendronobiloside A
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An efficient and versatile ZnBr2-catalyzed Diels-Alder/ carbocyclization cascade reaction has been developed for construction of highly functionalized cis-hydrindanes (70-96% yields with high diastereoselectivity), and it has been successfully utilized in the synthesis of the aglycon of dendronobiloside A.
- Han, Yejian,Zhu, Lizhi,Gao, Yuan,Lee, Chi-Sing
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supporting information; experimental part
p. 588 - 591
(2011/04/23)
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- Catalytic enantioselective friedel-crafts alkylations of indoles with α′-phosphoric enones
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The C2-symmetric bis(oxazoline) copper(II) complex proves to be an excellent catalyst in the Friedel-Crafts alkylation of indoles with α′-phosphoric enones. The enantioselectivities of this reaction are obtained in up to 98% ee.
- Yang, Hyeyeon,Hong, Young-Taek,Kim, Sunggak
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p. 2281 - 2284
(2008/02/04)
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- Synthesis of the Bestmann-Ohira reagent
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The conversion of an aldehyde to a terminal alkyne by means of a one-carbon chain extension is a key reaction in organic synthesis. By using dimethyl 1-diazo-2-oxopropylphosphonate, the Bestmann-Ohira reagent, the transformation can be achieved in one pot. A reliable, convenient sequence for the preparation of the Bestmann-Ohira reagent is described. Georg Thieme Verlag Stuttgart.
- Pietruszka, Joerg,Witt, Andreas
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p. 4266 - 4268
(2008/03/28)
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- The total synthesis and stereochemical revision of yanucamide A
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(Matrix presented) The first total synthesis of yanucamide A is reported via amide and ester couplings of the key components. This synthesis has established the configuration at the previously ambiguous 3-position, and also revised the stereochemistry at the 22-position, to give 3S,12S,17S,22S for the natural product.
- Xu, Zhengshuang,Peng, Yungui,Ye, Tao
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p. 2821 - 2824
(2007/10/03)
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- Method for preparing chiral diphosphines
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The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
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- An efficient route to chiral α- and β-hydroxyalkanephosphonates
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Enzymatic kinetic resolution of α- and β-hydroxyphosphonates in combination with ruthenium-catalyzed alcohol isomerization led to a successful dynamic kinetic resolution. A variety of racemic hydroxyphosphonates were efficiently transformed to the corresponding enantiomerically pure acetates (ee up to 99% and yield up to 87%).
- Pamies, Oscar,Baeckvall, Jan-E.
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p. 4815 - 4818
(2007/10/03)
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- 2, 3'-disubstituted-2-(2'-carboxycyclopropyl)glycines as potent and selective antagonists of metabotropic glutamate receptors
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2-(9-Xanthylmethyl)-2-(2'-carboxycyclopropyl) glycine 6e is a novel metabotropic glutamate receptor antagonist. A series of alpha, C-3' disubstituted (carboxycyclopropyl)glycines 6f-n were prepared. Antagonist activity was observed for all these compounds at group 2 and group 3 mGluRs. Although they were slightly less active on group 2 mGluRs than non C-3, substituted 6e, the compounds 6f-n were more selective with lesser or no activity on group 1 mGluR subtypes (IC50 values greater than 100μm).
- Collado, Ivan,Ezquerra, Jesus,Mazon, Angel,Pedregal, Concepcion,Yruretagoyena, Belen,Kingston, Anne E.,Tomlinson, Rosemary,Wright, Rebecca A.,Johnson, Bryan G.,Schoepp, Darryle D.
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p. 2849 - 2854
(2007/10/03)
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- Design and synthesis of haptens for application to the preparation of chiral 1,4-dihydropyridines
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Lipase-catalyzed enzymatic hydrolysis of dimethyl esters of 1,4- dihydropyridines to the monoester, which is an important intermediate for the synthesis of optically active 1,4-dihydropyridines, does not proceed directly. This paper describes the design and synthesis of novel haptens having a phosphonate group containing the requisite oxyanionic character to mimic the tetrahedral intermediate of hydrolysis, and the application of these compounds for generating antibodies with catalytic ability for the enantioselective partial hydrolysis of the dicarboxylic dimethyl ester (1) of a 1,4-dihydropyridine derivative to generate the monocarboxylic acid (2).
- Ikeda, Kiyoshi,Kato, Tatsuhisa,Suzuki, Takehisa,Achiwa, Kazuo
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p. 518 - 522
(2007/10/03)
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- On a safe and practical method for the preparation of β-keto phosphonates
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Acylations of the magnesium enolate derivatives of trimethyl and triethylphosphonoacetates, using a magnesium chloride-triethylamine system, lead to 2-acetylphosphonoacetates which are decarbalkoxylated to give β-keto phosphonates.
- Corbel, Bernard,L'Hostis-Kervella, Isabelle,Haelters, Jean-Pierre
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p. 2561 - 2568
(2007/10/03)
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- Process for producing optically active hydroxyalkylphosphonates
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Disclosed herein is a process for producing an optically active hydroxyalkylphosphonate represented by the formula (4), which comprises asymmetrically hydrogenating an oxoalkylphosphonate represented by the formula (1) using, as a catalyst, a ruthenium-optically active phosphine complex represented by the formula (2). STR1
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- Neighbouring Phosphonate Group Participation in Carbene Chemistry
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Systematic studies of the effect of the neighbouring phosphonate group on the reactivities of carbene showed that the neighbouring phosphonate group exerts prominent effects on both the product distribution and the reaction products; the results are interpreted as indicating the extent of participation, which seems to be sensitive to the carbenic substituents.
- Tomioka, Hideo,Hirai, Katsuyuki
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p. 1611 - 1613
(2007/10/02)
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- An Efficient Synthesis of Dialkyl 2-Oxoalkanephosphonates and Diphenyl-2-oxoalkylphosphine Oxides from 1-Chloralkyl Ketones
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The synthesis of dialkyl 2-oxoalkanephosphonates and diphenyl-2-oxoalkylphosphine oxides, via an Arbuzov reaction of trialkyl phosphites or ethoxydiphenylphosphine with methoxycarbonylhydrazono derivatives of 1-chloroalkyl ketones followed by carbonyl deprotection, is described.
- Corbel, Bernard,Medinger, Luc,Haelters, Jean Pierre,Sturtz, Georges
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p. 1048 - 1051
(2007/10/02)
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