cas 6048-29-9, PHENACYLTRIPHENYLPHOSPHONIUM BROMIDE

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Substituent effects in the formation of a few acenaphthenone-2-ylidene ketones and their molecular docking studies and in silico ADME profile
We observed intriguing substituent effects in the reaction between 4-substituted acetophenones and acenaphthenequinone in the presence of KOH in methanol. In all cases, expected Claisen-Schimdt condensation was the first step. However, depending on the nature of 4-substituent on acetophenone, the initially formed condensation product remain unchanged or underwent Domino sequence of reactions to give three different 2:2 adducts arising through three distinct pathways. The interactions of acenaphthenone-2-ylidene ketones with the target proteins were performed by molecular docking studies. The prediction of in silico ADME belongings of the synthesized compounds revealed substantial drug-likeness characters based on Lipinski's rules.
A, Jesna,Jacob, Jomon P.,Kuriakose, Daly,Thumpakara, Roshini K.
(2020/09/15)

Stereoselective Visible-Light Catalyzed Cyclization of Bis(enones): A Viable Approach to the Synthesis of Enantiomerically Enriched Cyclopentane Rings
Photoredox catalytic cyclization of aryl enones in the presence of visible light, promoted either by metals or organic dyes, represent a valuable strategy for the synthesis of cycloalkanes. The development of a stereoselective version of such transformation, in the presence of the metal-free catalyst Eosin Y was studied, with the aim to realize an efficient protocol for the in-flow synthesis of enantiomerically enriched functionalized cyclopentane rings, taking advantage of the flow reactors technology. The use of a chiral auxiliary on the bisenone to be cyclized offers a straightforward and convenient option to exert a stereocontrol on the light-driven cyclization. By exploiting Evans’ oxazolidinones, the stereoselective light-driven cyclization affords, after the removal of the chiral auxiliary, a functionalized 1,2-trans cyclopentane ring in up to 83/17 enantiomeric ratio. When the reaction was performed in continuo, in a homemade coil photoreactor, high yields were observed. The cyclization was also successfully realized in a 3D-printed mesoreactor, without any change in the diastereoseletctivity of the process.
Medici, Fabrizio,Resta, Simonetta,Presenti, Piero,Caruso, Lucia,Puglisi, Alessandra,Raimondi, Laura,Rossi, Sergio,Benaglia, Maurizio
supporting information
p. 4521 - 4524
(2021/06/12)

Cascade Oxidative C?H Annulation of Thiophenes: Heck-Type Pathway Enables Concise Access to Thienoacenes
The pursuit of efficient synthetic route to thienoacenes represents an appealing yet challenging task in the fields of both organic synthetic chemistry and organic functional materials. In this work, we disclose a rhodium-catalyzed cascade C?H annulation of phenacyl phosphoniums with (benzo)thiophenes via a Heck-type pathway to provide a new class of planar thienoacenes, which involves the formation of three Caryl-Caryl bonds and one Caryl?O bond in a single operation. The neutral S,O-heteroacenes exhibit superior stability and adopt a herringbone-like packing mode with efficient π–π stacking in the crystals, suggesting their potential in organic semiconducting materials. This work first exemplifies the superiority of cascade oxidative C?H annulation involving a Heck-type pathway in the development of concise access to heteroacenes.
Chen, Xingyu,Yang, Yudong,Han, Weiguo,Huang, Quan,Huang, Zhenmei,You, Jingsong
supporting information
p. 12371 - 12375
(2021/05/03)

Silica gel-promoted synthesis of multisubstituted spiroindolenines from tryptamines and γ-chloro-α,β-unsaturated ketones
Here we report a one-pot synthesis of multisubstituted spiroindolenines from a series of tryptamine derivatives with γ-chloro-α,β-unsaturated ketones. The reaction sequence consists of base-induced condensation and silica gel-promoted intramolecular Michael addition. The target molecules are afforded in up to 90% yield with up to >20:1 diastereoselectivity.
Liu, Qiang-Qiang,Zheng, Chao,You, Shu-Li
(2020/12/02)

Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
Liu, Xin,Werner, Thomas
supporting information
p. 1096 - 1104
(2020/12/31)

Rh(iii)-catalyzed diastereoselective cascade annulation of enone-tethered cyclohexadienonesviaC(sp2)-H bond activation
Herein, we report highly diastereoselective arylative cyclization of enone-tethered cyclohexadienonesviaRh(iii)-catalyzed C-H activation ofN-methoxybenzamides. This reaction proceeds through the formation of a five-membered rhodacycle followed by bis-Michael cascade annulation to access functionalized bicyclic scaffolds with four contiguous stereocenters with a broad substrate scope. These products have excellent functional handles, allowing further synthetic transformation to increase the structural complexity. Furthermore, mechanistic studies of arylative cyclization and a gram-scale experiment are also presented.
Chegondi, Rambabu,Jadhav, Sandip B.,Maurya, Sundaram,Navaneetha, N.
supporting information
p. 13598 - 13601
(2021/12/23)

Functionality study of chalcone-hydroxypyridinone hybrids as tyrosinase inhibitors and influence on anti-tyrosinase activity
In an attempt to synthesise new tyrosinase inhibitors, we designed and synthesised a series of chalcone-hydroxypyridinone hybrids as potential tyrosinase inhibitors adopting strategic modifications of kojic acid. All the newly synthesised compounds were characterised by NMR and mass spectrometry. Initial screening of the target compounds demonstrated that compounds 1a, 1d, and 1n had relatively strong inhibitory activities against tyrosinase monophenolase, with IC50 values of 3.07 ± 0.85, 2.25 ± 0.8 and 2.75 ± 1.19 μM, respectively. The inhibitory activity against monophenolase was 6- to 8-fold higher than that of kojic acid. Compounds 1a, 1d, and 1n also showed inhibition of diphenolase, with IC50 values of 17.05 ± 0.07, 11.70 ± 0.03 and 19.3 ± 0.28 μM, respectively. The inhibition kinetics of diphenolase indicates that compounds 1a and 1d induce reversible inhibition on tyrosinase. Finally, we found that copper coordination should be one of the important inhibitory mechanism of these compounds in tyrosinase.
Singh, L. Ravithej,Chen, Yu-Lin,Xie, Yuan-Yuan,Xia, Wei,Gong, Xing-Wen,Hider, Robert C.,Zhou, Tao
p. 1562 - 1567
(2020/08/07)

Asymmetric Catalytic Diverse Ring Opening/Cycloadditions of Cyclobutenones with (E)-Alkenyloxindoles and (E)-Dioxopyrrolidines
Highly enantioselective ring-opening/cycloaddition reactions of cyclobutenones were achieved by employing chiral N,N′-dioxide/metal complexes as the catalysts. The Diels-Alder type cycloaddition with (E)-alkenyloxindoles yielded spirocyclohexaneoxindoles with excellent results. Meanwhile, a hetero-Diels-Alder process occurred with (E)-dioxopyrrolidines to afford spiropyrrolidinone-dihydropyranone derivatives.
Luo, Yao,Zhang, Hang,Wang, Siyuan,Zhou, Yuqiao,Dong, Shunxi,Feng, Xiaoming
supporting information
p. 2645 - 2650
(2020/04/02)

Visible Light Induced Cyclization to Spirobi[indene] Skeletons from Functionalized Alkylidienecyclopropanes
In this paper, we revealed a metal-free and visible light photoinduced method for the rapid construction of spirobi[indene] skeletons, providing a simple and efficient way for easy access to spirobi[indene] scaffolds under mild conditions along with a broad substrate scope and good functional group tolerance.
Li, Quanzhe,Liu, Jiaxin,Shi, Min,Wei, Yin
supporting information

(2020/03/26)

Quaternary Phosphonium Salts as Active Br?nsted Acid Catalysts for Friedel-Crafts Reactions
A readily available quaternary phosphonium salt containing a trifluoroacetonyl group and a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF4-) counterion was demonstrated to be a highly active Br?nsted acid catalyst for Friedel-Crafts-type reactions of an array of electron-rich heteroarenes and aniline derivatives with isatin-derived ketimines, even at 0.1 mol % catalyst loadings.
Chen, Lin,Xiao, Ben-Xian,Du, Wei,Chen, Ying-Chun
supporting information
p. 5733 - 5736
(2019/08/01)

One-Pot Synthesis of 2,5-Disubstituted Furans through In Situ Formation of Allenes and Enolization Cascade
A one-pot synthesis of 2,5-disubstituted furans from γ-ketoacids is reported. In situ formation of allenoates by action of chloroformate on carboxylic acid following by enolization of ketone affords furan derivatives by cyclization. The reaction was extended to a wide scope of ketoacids and phosphonium salts. This methodology was applied on levulinic acid and derivatives, one of the biosourced platform chemicals.
Bernhard, Yann,Gilbert, Joachim,Bousquet, Till,Favrelle-Huret, Audrey,Zinck, Philippe,Pellegrini, Sylvain,Pelinski, Lydie
supporting information
p. 7870 - 7873
(2019/12/24)

A Ba/Pd Catalytic System Enables Dehydrative Cross-Coupling and Excellent E-Selective Wittig Reactions
A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.
Xie, Peizhong,Fu, Weishan,Cai, Xinying,Sun, Zuolian,Wu, Ying,Li, Shuangshuang,Gao, Cuiqing,Yang, Xiaobo,Loh, Teck-Peng
supporting information
p. 7055 - 7059
(2019/09/12)

PYRROLIDINE DERIVATIVES AS PPAR AGONISTS
The present invention discloses a class of pyrrolidine derivatives as PPAR agonist, and their use for the treatment of some diseases of PPAR receptor-associated pathways (such as nonalcoholic steatohepatitis and concurrent fibrosis, insulin resistance, primary biliary cholgangitis, dyslipidenmia, hyperlipidemia, hypercholesterolemia, atherosclerosis, hypertriglyceridemia, cardiovascular disease, obesity or the like). In particular, the present invention discloses a compound represented by Formula (I) or a pharmaceutically acceptable salt thereof.
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Paragraph 0693-0695

(2019/08/02)

Potassium 2-oxo-3-enoates as Effective and Versatile Surrogates for α, β-Unsaturated Aldehydes in NHC-Catalyzed Asymmetric Reactions
Potassium 2-oxo-3-enoates, which are readily prepared at scale and easily stored, have been found to be effective and versatile surrogates for α,β-unsaturated aldehydes in NHC-catalyzed asymmetric reactions. Promoted by chiral N-heterocyclic carbenes combined with LiCl, these easy-to-handle solid salts could release of CO2 and then undergo asymmetric reactions via homoenolate and α, β-unsaturated acyl azolium intermediate. The reactions have broad substrate scopes with high enantioselectivities. (Figure presented.).
Gao, Yaru,Ma, Yafei,Xu, Chen,Li, Lin,Yang, Tianjian,Sima, Guoqing,Fu, Zhenqian,Huang, Wei
supporting information
p. 479 - 484
(2017/12/26)

Fe-Catalyzed Cycloisomerization of Aryl Allenyl Ketones: Access to 3-Arylidene-indan-1-ones
A cycloisomerization of aryl allenyl ketones to 3-arylidene-indan-1-ones using a cationic Fe-complex as a catalyst is reported. The catalyst opens a synthetically interesting reaction pathway to this surprisingly underrepresented class of indanones that are not accessible using alternative catalytic systems.
Teske, Johannes,Plietker, Bernd
supporting information
p. 2257 - 2260
(2018/04/27)

Generation and Rearrangement of N,O-Dialkenylhydroxylamines for the Synthesis of 2-Aminotetrahydrofurans
A new diastereoselective route to 2-aminotetrahydrofurans has been developed from N,O-dialkenylhydroxylamines. These intermediates undergo a spontaneous C?C bond-forming [3,3]-sigmatropic rearrangement followed by a C?O bond-forming cyclization. A copper-catalyzed N-alkenylation of an N-Boc-hydroxylamine with alkenyl iodides, and a base-promoted addition of the resulting N-hydroxyenamines to an electron-deficient allene, provide modular access to these novel rearrangement precursors. The scope of this de novo synthesis of simple nucleoside analogues has been explored to reveal trends in diastereoselectivity and reactivity. In addition, a base-promoted ring-opening and Mannich reaction has been discovered to covert 2-aminotetrahydrofurans to cyclopentyl β-aminoacid derivatives or cyclopentenones.
Son, Jongwoo,Reidl, Tyler W.,Kim, Ki Hwan,Wink, Donald J.,Anderson, Laura L.
supporting information
p. 6597 - 6600
(2018/05/03)

Catalytic Cyclooligomerization of Enones with Three Methylene Equivalents
Cyclic structures are highly represented in organic molecules, motivating a wealth of catalytic methods targeting their synthesis. Among the various ring-forming processes, cyclooligomerization reactions possess several attractive features but require addressing a unique challenge associated with controlling ring-size selectivity. Here we describe the catalytic reductive cocyclooligomerization of an enone and three carbene equivalents to generate a cyclopentane, a process that constitutes a formal [2 + 1 + 1 + 1]-cycloaddition. The reaction is promoted by a (quinox)Ni catalyst and uses CH2Cl2/Zn as the C1 component. Mechanistic studies are consistent with a metallacycle-based pathway, featuring sequential migratory insertions of multiple carbene equivalents to yield cycloalkanes larger than cyclopropanes.
Farley, Conner M.,Zhou, You-Yun,Banka, Nishit,Uyeda, Christopher
supporting information
p. 12710 - 12714
(2018/10/09)

Divergent Access to 1-Naphthols and Isocoumarins via Rh(III)-Catalyzed C-H Activation Assisted by Phosphonium Ylide
Rh-catalyzed C-H activation of phenacyl phosphoniums in coupling with α-diazocarbonyl compounds has been realized with the assistance of a mutifunctional phosphonium ylidic directing group, providing expedient accesses to 1-naphthols and isocoumarins. Switchable synthesis of 1-naphthols and isocoumarins was realized by substrate control, where these transformations were enabled by initial C-H activation and subsequent intramolecular Wittig reaction or nucleophilic C-O formation.
Li, Yunyun,Wang, Qiang,Yang, Xifa,Xie, Fang,Li, Xingwei
supporting information
p. 3410 - 3413
(2017/07/15)

Synthesis of trifluoromethyl-/cyclopropyl-substituted 2-isoxazolines by DBU-promoted domino reaction
NTrifluoromethyl and cyclopropyl substituted 2-isoxazolines were synthesized via a DBU-promoted domino reaction of β-trifluoromethyl-/β-cyclopropyl-substituted enones with hydroxylamine. The domino reaction consists of a Michael addition and the followed cyclization. A wide range of 3-substituted 5-cyclopropyl-5- trifluoromethyl-2-isoxazolines were obtained in good to excellent yields under mild reaction conditions. The method could also apply to other trifluoromethyl-substituted enones.
Liu, Xiao-Dong,Ma, Hai-Yan,Xing, Chun-Hui,Lu, Long
supporting information
p. 1780 - 1783
(2017/07/27)

A convenient synthesis of 4-alkyl-3-benzoylpyrroles from α,β-unsaturated ketones and tosylmethyl isocyanide
A convenient synthesis of 4-alkyl-3-benzoyl pyrrole was achieved from α,β-unsaturated ketones and tosylmethyl isocyanide in the presence of mild base LiOH·H2O. This method is very economical and was successfully utilized for the synthesis of various 4-alkyl-3-benzoylpyrrole derivatives with good to excellent yields.
Kumar, Kapil,More, Shital S.,Goyal, Sandeep,Gangar, Mukesh,Khatik, Gopal L.,Rawal, Ravindra K.,Nair, Vipin A.
supporting information
p. 2315 - 2319
(2016/05/10)

Transaminase Triggered Aza-Michael Approach for the Enantioselective Synthesis of Piperidine Scaffolds
The expanding “toolbox” of biocatalysts opens new opportunities to redesign synthetic strategies to target molecules by incorporating a key enzymatic step into the synthesis. Herein, we describe a general biocatalytic approach for the enantioselective preparation of 2,6-disubstituted piperidines starting from easily accessible pro-chiral ketoenones. The strategy represents a new biocatalytic disconnection, which relies on an ω-TA-mediated aza-Michael reaction. Significantly, we show that the reversible enzymatic process can power the shuttling of amine functionality across a molecular framework, providing access to the desired aza-Michael products.
Ryan, James,?iau?iulis, Mindaugas,Gomm, Andrew,Maciá, Beatriz,O’Reilly, Elaine,Caprio, Vittorio
supporting information
p. 15798 - 15800
(2016/12/22)

Enantioselective Organocatalytic Cascade Approach to Different Classes of Benzofused Acetals
A novel enantioselective organocatalytic strategy is presented for the synthesis of tetrahydrofurobenzofuran and methanobenzodioxepine natural product core structures. The strategy is based on a pair of divergent reaction pathways in which hydroxyarenes react with γ-keto-α,β-unsaturated aldehydes, catalyzed by a chiral secondary amine. One reaction pathway, which leads to chiral 5,5-fused acetals with two stereocenters—the tetrahydrofurobenzofuran scaffolds—proceeds in moderate yields and up to 96 % ee. The other reaction pathway provides 5,6-bridged methanobenzodioxepine scaffolds with three stereocenters in moderate to good yields and up to 95 % ee. The reaction is remarkable as it can proceed with catalyst loadings as low as 0.25 mol %, providing one of the highest known turnover numbers in iminium ion catalysis. Furthermore, the hemiacetal tetrahydrofurobenzofuran can undergo functionalizations including reduction, oxidation, and allylation. Finally, the effects involved in the substrate control for the divergent pathways, based on both experimental and computational studies, have been investigated. A model involving steric, electronic and stereoelectronic interactions is discussed to rationalize the observed selectivities.
Paz, Bruno Matos,Klier, Lydia,N?sborg, Line,Lauridsen, Vibeke Henriette,Jensen, Frank,J?rgensen, Karl Anker
supporting information
p. 16810 - 16818
(2016/11/16)

Synthesis of Polysubstituted Pyridines via a One-Pot Metal-Free Strategy
An efficient strategy for the one-pot synthesis of polysubstituted pyridines via a cascade reaction from aldehydes, phosphorus ylides, and propargyl azide is reported. The reaction sequence involves a Wittig reaction, a Staudinger reaction, an aza-Wittig reaction, a 6π-3-azatriene electrocyclization, and a 1,3-H shift. This protocol provides quick access to the polysubstituted pyridines from readily available substrates in good to excellent yields.
Wei, Hongbo,Li, Yun,Xiao, Ke,Cheng, Bin,Wang, Huifei,Hu, Lin,Zhai, Hongbin
supporting information
p. 5974 - 5977
(2016/01/09)

Design and synthesis of 3-trifluoromethyl-3h-pyrazoles and further investigations of their transformation to 1h-pyrazoles
An efficient intramolecular cycloaddition strategy for the synthesis of trifluoromethyl-substituted 3H-pyrazoles was developed. Subsequently, their wide applications were demonstrated: they (1) react with dioxane by a radical process and (2) undergo [1,5] sigmatropic rearrangements. These applications are useful as the products were obtained in high yields and with excellent regioselectivity.
Sha, Qiang,Liu, Haixuan,Wei, Yunyang
p. 7707 - 7715
(2015/04/22)

Identification of novel chromenone derivatives as interleukin-5 inhibitors
A series of (E)-5-alkoxy-3-(3-phenyl-3-oxoprop-1-enyl)-4H-chromen-4-ones (4) and (E)-5-alkoxy-3-(3-hydroxy-3-phenylprop-1-enyl)-4H-chromen-4-ones (5) were synthesized and evaluated for their IL-5 inhibitory activity. Propenone analogs 4 possess some of the structurally important characteristics of isoflavone 2 and chalcone 3 previously known as potent IL-5 inhibitor. However, the inhibitory activity of 4 was weak and therefore this structural hybridization appears to be ineffective for the design of IL-5 inhibitor. Meanwhile the potent activity profile of compounds 5 was discovered. This enhanced activity of 5 compared to 4 could be due to the effective location of hydroxyl group of allylic alcohol moiety of 5 in the 3D structure. The electron withdrawing substituents at position 4 of phenyl ring of 5 enhances the activity possibly due to an increase in the strength of hydrogen bonding property of hydroxyl group of allylic alcohol moiety.
Venkateswararao, Eeda,Kim, Min-Seok,Sharma, Vinay K.,Lee, Ki-Cheul,Subramanian, Santhosh,Roh, Eunmiri,Kim, Youngsoo,Jung, Sang-Hun
p. 31 - 38
(2013/03/13)

[4+2] Annulation of vinyl ketones initiated by a phosphine-catalyzed aza-Rauhut-currier reaction: A practical access to densely functionalized tetrahydropyridines
The first example of phosphine catalyzed aza-Rauhut-Currier reaction initiated [4+2] annulation of vinyl ketones with N-sulfonyl-1-aza-1,3-dienes has been disclosed. Under the ambient conditions, this protocol provides a practical access to valuable densely functionalized tetrahydropyridines in good to excellent yields and high diastereoselectivities (see scheme). Copyright
Shi, Zugui,Tong, Qinjie,Leong, Wendy Wen Yi,Zhong, Guofu
supporting information; scheme or table
p. 9802 - 9806
(2012/09/07)

Kinetics and mechanism of gas-phase pyrolysis of ylides. Part 3. 1 Thermal reactivity of α-carbonyl- and thiocarbonyl-stabilized methylenetriphenylphosphoranes
Fourteen ketone/thione-stabilized triphenylphosphonium methylides were subjected to conventional gas-phase and flash vacuum pyrolysis (FVP). The kinetics of the first-order thermal gas-phase reactions of all these compounds were investigated over 360-653K temperature range. The values of the Arrhenius logA and energy of activation of these ylides averaged 11.52±0.34s -1 and 133.20±3.14kJmol-1, respectively. The products of sealed-tube (static) and FVP were analyzed and compared. A mechanism is proposed to account for the products of reaction. The rate constants [k (s-1)] of the substrates at 500K were calculated and used to substantiate the proposed mechanism of pyrolysis, and to rationalize the thermal gas-phase reactivities of the ylides under study.
Al-Bashir, Rasha F.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M. E.
experimental part
p. 311 - 319
(2012/04/17)

Highly efficient route to functionalized tetrahydrocarbazoles using a tandem cross-metathesis/intramolecular-hydroarylation sequence
The scope of the novel ruthenium-catalyzed tandem cross-metathesis/ intramolecular-hydroarylation sequence is described. This methodology offers a practical and efficient synthesis of structurally diverse and complex tetrahydrocarbazoles in good to excellent yields (up to 98%). Moreover, preliminary efforts towards the development of an enantioselective version of the current process by sequential catalysis with ruthenium complex and chiral amine are presented, with high yields and enantioselectivities (up to 88% yield and 91% ee).
An, Xiao-Lei,Chen, Jia-Rong,Li, Chang-Feng,Zhang, Fu-Gen,Zou, You-Quan,Guo, Ying-Cen,Xiao, Wen-Jing
supporting information; experimental part
p. 2258 - 2265
(2011/06/11)

Enantioselective copper-catalyzed reductive michael cyclizations
In the presence of siloxanes as stoichiometric reductants, chiral copper-bisphosphine complexes catalyze highly enantioselective reductive Michael cyclizations of substrates containing two α,β-unsaturated carbonyl moieties. The diastereochemical outcome of these reactions Is dependent upon whether biaryl- or ferrocene-based chiral bisphosphines are employed.
Oswald, Claire L.,Peterson, Justine A.,Lam, Hon Wal
supporting information; experimental part
p. 4504 - 4507
(2009/12/07)

New access to trisubstitutea 3-pyrrolines under phosphine catalysis
Conjugated dienes, properly activated by electron-withdrawing groups on both ends, are shown to be suitable substrates for phosphinepromoted organocatalytic processes. Their reactions with imines, under phosphine catalysis, afford a new and efficient synthetic approach to functionalized 3-pyrrolines.
Schuler, Marie,Duvvuru, Deepti,Retailleau, Pascal,Betzer, Jean-Francois,Marinetti, Angela
supporting information; scheme or table
p. 4406 - 4409
(2009/12/26)

Diene-yne cyclisation reactions of 1-ethynyl-2-vinyl-3,4- dihydronaphthalenes and 1-ethynyl-2-vinylnaphthalenes
The reaction of 1-ethynyl-2-vinyl-3,4-dihydronaphthalenes and 1-ethynyl-2-vinylnaphthalenes over RuCI2(p-cymene) PPh3 leads to 9,10-dihydrophenanthrenes and phenanthrenes in those cases where the ethynyl group in the substrates carries a terminal proton. When 1-phenylethynyl-2-vinyl-3,4-dihydronaphthalenes or 1-phenylethynyl-2- vinylnaphthalenes are reacted over Pt(PPh3)4, 1-methylene-1H-benz[e]-4,5-dihydroindenes and 1-methylene-1H-benz[e]indenes are formed.
Watanabe, Masataka,Shiine, Kodai,Ldeta, Keiko,Matsumoto, Taisuke,Thiemann, Thies
experimental part
p. 669 - 678
(2009/09/06)

NOVEL FLUORINATED ALKYLFLUOROPHOSPHORIC ACID SALT OF ONIUM AND TRANSITION METAL COMPLEX
[Problems] To obtain a polymerization initiator (acid generating agent) having excellent power for initiation of cationic polymerization without containing arsenic or antimony. [Means for solution] Provided is a specific onium salt or transition metal complex salt of a fluorinated alkyl fluorophosphoric acid.
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(2010/11/25)

Reaction of triphenyl(phenylethynyl)phosphonium bromide with α-aminoethers, dipiperidinomethane, and secondary amines
The reactions of triphenyl(phenylethynyl)phosphonium bromide with α-aminoethers lead to formation of triphenyl(2-amino-2-phenylvinyl) phosphonium bromides. In the case of acyclic aminoethers, this reaction is accompanied by the formation of the corresponding amine hydrobromide and triphenylphosphine oxide by a scheme analogous to that of alkaline hydrolysis of phosphonium salts and involving attack of the amine on the phosphorus atom. The reaction of the same salt with diethyl-or dipropylamine affords hydrobromides of the latter, while with piperidine, together with salts, its adduct by the triple bond is formed. Piperidinomethane with the same salt forms triphenylphosphonium (2-phenyl-2-piperidinovinyl)phosphonium bromide. Nauka/Interperiodica 2007.
Bagdasaryan,Pogosyan,Panosyan,Indzhikyan
p. 866 - 870
(2008/02/13)

Synthesis, antifungal activity, and structure-activity relationships of coruscanone A analogues
Coruscanone A, a plant-derived cyclopentenedione derivative, showed potent in vitro antifungal activity against Candida albicans and Cryptococcus neoformans comparable to amphotericin B and fluconazole. A series of analogues have been synthesized by modification of the cyclopentenedione ring, the enolic methoxy functionality, and the side chain styryl moiety of this natural product lead. A structurally close 1,4-benzoquinone analogue was also prepared. All the compounds were examined for their in vitro activity against major opportunistic fungal pathogens including C. albicans, C. neoformans, and Aspergillus fumigatus and fluconazole-resistant C. albicans strains, with several analogues demonstrating potent antifungal activity. Structure-activity relationship studies indicate that the 2-methoxymethylenecyclopent-4-ene-1,3-dione structural moiety is the pharmacophore responsible for the antifungal activity of this class of compounds while the side chain styryl-like moiety plays an important complementary role, presumably contributing to target binding.
Babu, K. Suresh,Li, Xing-Cong,Jacob, Melissa R.,Zhang, Qifeng,Khan, Shabana I.,Ferreira, Daneel,Clark, Alice M.
p. 7877 - 7886
(2007/10/03)

A convenient method for the preparation of α-vinylfurans by phosphine-initiated reactions of various substituted enynes bearing a carbonyl group with aldehydes
α-Vinylfurans were obtained by phosphine-initiated cyclization of various enynes bearing a carbonyl group at the ene end in the presence of various aldehydes, in moderate to high yields. The reaction may consist of 1,6-addition of phosphine to the enynes, ring closure, and Wittig reaction between the ylid resulting from cyclization and an aldehyde. Thus, various aldehydes were able to be used in the reaction. The reaction was influenced greatly by the substituents at the acetylene position (R1) and the α-position of the carbonyl group (R3).
Kuroda, Hirofumi,Hanaki, Emi,Izawa, Hironori,Kano, Michiko,Itahashi, Hiromi
p. 1913 - 1920
(2007/10/03)

Solvent-free mechanochemical preparation of phosphonium salts, phosphorus ylides, and olefins
The present invention provides a method of preparing a phosphonium salt of the formula [R1R2R3P—CR4R5R6]X, comprising ball-milling a phosphine of the formula R1R2R3P with a compound of the formula XCR4R5R6; a method of preparing a phosphorus ylide of the formula R1R2R3P═CR4R5, comprising ball-milling a phosphonium salt of the formula [R1R2R3P—HCR4R5]X in the presence of a base; and a method of preparing an olefin of the formula R4R5C═CR7H or R4R5C═CR7R8, comprising ball-milling a phosphorus ylide of the formula R1R2R3P═CR4R5 with a compound of the formula R7C(O)H or R7C(O)R8. The inventive method produces phosphonium salts and phosphorus ylides by mechanical processing solid reagents under solvent-free conditions. The advantages of the present invention over conventional solution methods, include: (1) extremely high selectivity; (2) high yields; (3) low processing temperatures; (4) simple and scalable reactions using commercially available equipment; and (5) the complete elimination of solvents from the reaction.
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(2008/06/13)

Fluorinated butanolides and butenolides - Part 9. Synthesis of 2-(trifluoromethyl)butan-4-olides by Wittig reaction using methyl 3,3,3-trifluoropyruvate
2-(Trifluoromethyl)butan-4-olides 13 and 14 were prepared by a three-step synthesis starting from a Wittig reagent and methyl 3,3,3-trifluoropyruvate (1) as a building block. The Wittig reaction of (2-oxoalkyl)triphenylphosphonium bromides with pyruvate 1 gave intermediate 4-oxobutenoates 8 and 9, which were stepwise selectively reduced with zinc borohydride firstly at the double bond and subsequently at the oxo group to afford unstable 4-hydroxy-2-trifluoromethylalkanoates 11 and 12, which cyclised spontaneously to the end butenolides 13 and 14.
Palecek, Jiri,Kvicala, Jaroslav,Paleta, Oldrich
p. 177 - 183
(2007/10/03)

Solvent-free mechanochemical synthesis of phosphonium salts
Phosphonium salts have been prepared during high-energy ball-milling of triphenylphosphine with solid organic bromides; the reactions occur at ambient conditions without a solvent; in the case of 2-bromo-2-phenylacetophenone the reaction in a solution usually produces a mixture containing both the C-phosphorylated and O-phosphorylated compounds, while the solvent-free mechanically induced transformation results in the thermodynamically favorable C-phosphorylated product; the occurrence of the observed transformations during mechanical processing of solid reactants is confirmed by the solid-state 31P NMR spectroscopy and X-ray powder diffraction.
Balema, Viktor P.,Wiench, Jerzy W.,Pruski, Marek,Pecharsky, Vitalij K.
p. 724 - 725
(2007/10/03)

Degradational cyclization of α-[2-phenyl-2- (phenylsulfonylhydrazono)ethyl]phenacylidenetriphenylphosphoranes to 3,6- diphenylpyridazines and 5-benzoyl-3-phenylpyrazoles
α-[2-Phenyl-2- (phenylsulfonylhydrazono)ethyl]phenacylidenetriphenylphosphoranes were obtained (60-71%) by the reaction between phenylsulfonylhydrazones of phenacyl bromides and phenacylidenetriphenylphosphoranes. Thermolysis of the phosphoranes gave 3,6-diphenylpyridazines (43-66%) and 5-benzoyl-3- phenylpyrazoles (13-27%), together with triphenylphosphine oxide and S-phenyl benzenethiosulfonate, a disproportionation product from benzenesulfinic acid. The structure of the intermediate α-substituted phenacylidenetriphenylphosphorane was confirmed by an X-Ray diffraction method.
Ito, Suketaka,Kakehi, Akikazu,Okada, Kyoko
p. 2949 - 2960
(2007/10/03)

Benzoylmethylenetriphenylphosphorane, C26H21OP
The air-stable phosphorane (2-oxo-2-phenyltriphenylphosphoniumethylide) is shown to be a resonance hybrid of an ylene, ylidic and enolate canonical assembly.The geometry around the P atom is nearly tetrahedral.The O atom is oriented cis to the P atom.The phenyl ring of the benzoyl group is twisted with respect to the plane containing the carbonyl group.
Kalyanasundari, M.,Panchanatheswaran, K.,Parthasarathi, V.,Robinson, Ward T.,Wen, Huo
p. 1738 - 1741
(2007/10/02)

REACTION OF WITTIG REAGENTS WITH α,α-DIHALOKETONES. DIBENZOYLMETHANE DIBROMIDE AND 1,3-INDANDIONE DIBROMIDE
Dibenzoylmethane dibromide (5) and 1,3-indandione dibromide (6) react with ylide-phosphoranes 1a-c to give the α,β-unsaturated esters 10 and 13, respectively.All intermediates are isolated and identified.Structures 10 and 13 as well as the intermediates were confirmed by compatible analytical and spectroscopic results.
Abdou, Wafaa M.,Ganoub, Neven A. F.
p. 49 - 55
(2007/10/02)

Pyrrole analogs of mevalonolactone, derivatives thereof and pharmaceutical use
Compounds of the formula STR1 wherein R1 is C1-6 alkyl not containing an asymmetric carbon atom, C3-7 cycloalkyl or STR2 wherein R5, R6 and R7 are as defined below, R2 is C1-6 alkyl not containing an asymmetric carbon atom, C3-7 cycloalkyl or STR3 wherein R8, R9 and R10 are as defined below. R3 is hydrogen, C1-6 alkyl not containing an asymmetric carbon atom, C3-7 cycloalkyl or STR4 wherein R11, R12 and R13 are as defined below, R4 is hydrogen, C1-6 alkyl not containing an asymmetric carbon atom, C7-7 cycloalkyl or STR5 wherein R14, R15 and R16 are as defined below, X is --(CH2)m --, --CH=CH--, --CH=CH--CH2 -- or --CH2 --CH=CH--, wherein m is 0, 1, 2 or 3, and Z is STR6 wherein R17 is hydrogen or C1-3 alkyl, and R18 is hydrogen, R19 or M, wherein R19 is a physiologically acceptable ester group, and M is a pharmaceutically acceptable cation, wherein each of R5, R8, R11 and R14 is independently hydrogen, C1-3 alkyl, n-butyl, i-butyl, t-butyl, C1-3 alkoxy, n-butoxy, i-butoxy, trifluoromethyl, fluoro, chloro, bromo, phenyl, phenoxy or benzyloxy, each of R6, R9, R12 and R15 is independently hydrogen, C1-3 alkyl, C1-3 alkoxy, trifluoromethyl, fluoro, chloro, bromo, phenoxy or benzyloxy, and each of R7, R10, R13 and R16 is independently hydrogen, C1-2 alkyl, C1-2 alkoxy, fluoro or chloro, with the provisos that not more than one substituent on each of Rings A, B, C and D independently is trifluoromethyl, not more than one substituent on each of Rings A, B, C and D independently is phenoxy, and not more than one substituent on each of Rings A, B, C and D independently is benzyloxy, with the provisos that (i) the --X--Z group is in the 2- or 3-position of the pyrrole ring, (ii) the --X--Z group is ortho to both R1 and R2, and (iii) R3 is ortho to R2, the use thereof for inhibiting cholesterol biosynthesis and lowering the blood cholesterol level and, therefore, in the treatment of hyperlipoproteinemia and atherosclerosis, pharmaceutical compositions comprising such compounds and processes for and intermediates in the synthesis of such compounds.
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(2008/06/13)

REACTION OF ARACYL- AND ALKOXYCARBONYLMETHYLSELENONIUM SALTS WITH NUCLEOPHILIC REAGENTS
A method is proposed for the synthesis of α-methylselenium derivatives of aryl and heteryl methyl ketones and ethyl acetate by demethylation of readily available aracyl-, heteroacyl-, and methoxycarbonylmethylselenonium salts with triethylamine.It was established that triphenylphosphine cleaves dimethylphenacylselenonium bromide both at the Se-methyl and at the Se-CH2COPh bond (preferentially).Triphenylphosphine selenide is formed in this reaction in addition to the corresponding phosphonium salts.
Magdesieva, N. N.,Kyandzhetsian, R. A.,Kirpichenok, M. A.,Chovnikova, N. G.
p. 2279 - 2284
(2007/10/02)

Electrogeneration of Cyanomethyl Anion from Phenylsulphonylacetonitrile and Cyanomethyltrimesitylphosphonium Iodide and the Relative Acidities of XCH2CN (X=Ph3P(1+), Ph3As(1+), Mes3P(1+), or PhSO2) versus Acetic Acid in Acetonitrile
Contrary to a previous report, PhSO2CH2CN has been shown to exhibit a one-electron reduction (two-electron reductive cleavage followed by deprotonation of PhSO2CH2CN by (1-)CH2CN).Mes3P(1+)CH2CN I(1-) behaves similarly.The relative acidities of XCH2CN (X= Ph3P(1+), Ph3As(1+), Mes3P(1+), or PhSO2) versus acetic acid in acetonitrile has been studied both voltammetrically and spectrophotometrically.Ph3P(1+)CH2CN is a stronger acid than CH3CO2H; Ph3As(1+)CH2CN, Mes3P(1+)CH2CN, and PhSO2CH2CN are weaker acids than CH3CO2H.PhSO2CH2CN and Mes3P(1+)CH2CN I(1-) have been used in an electroanalytical method for studying the addition of (1-)CH2CN to various electrophiles.
Bellamy, Anthony J.,MacKirdy, Iain S.
p. 1093 - 1098
(2007/10/02)