- Photoinduced Regioselective Olefination of Arenes at Proximal and Distal Sites
-
The Fujiwara-Moritani reaction has had a profound contribution in the emergence of contemporary C-H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had
- Ali, Wajid,Anjana, S. S.,Bhattacharya, Trisha,Chandrashekar, Hediyala B.,Goswami, Nupur,Guin, Srimanta,Maiti, Debabrata,Panda, Sanjib,Prakash, Gaurav,Saha, Argha,Sasmal, Sheuli,Sinha, Soumya Kumar
-
supporting information
p. 1929 - 1940
(2022/02/01)
-
- Enantiodivergent One-Pot Synthesis of Axially Chiral Biaryls Using Organocatalyst-Mediated Enantioselective Domino Reaction and Central-to-Axial Chirality Conversion
-
Enantiodivergent one-pot synthesis of biaryls was developed using a catalytic amount of a single chiral source. A domino organocatalyst-mediated enantioselective Michael reaction and aldol condensation provided centrally chiral dihydronaphthalenes with excellent enantioselectivity, from which an enantiodivergent chirality conversion from central-to-axial chirality was achieved. Both enantiomers of biaryls were obtained with excellent enantioselectivity. All transformations can be conducted in a single reaction vessel. A plausible reaction mechanism for the enantiodivergence is proposed.
- Hayashi, Yujiro,Koshino, Seitaro,Kwon, Eunsang,Monde, Kenji,Taniguchi, Tohru
-
supporting information
p. 15786 - 15794
(2021/10/14)
-
- Hypervalent iodine(iii) induced oxidative olefination of benzylamines using Wittig reagents
-
We have developed hypervalent iodine(iii) induced oxidative olefination of primary and secondary benzylamines using 2C-Wittig reagents, which provides easy access to α,β-unsaturated esters. Mild reaction conditions, good to excellent yields with high (E) selectivity, and a broad substrate scope are the key features of this reaction. We have successfully carried out the gram-scale synthesis of α,β-unsaturated esters.
- Ramavath, Vijayalakshmi,Rupanawar, Bapurao D.,More, Satish G.,Bansode, Ajay H.,Suryavanshi, Gurunath
-
p. 8806 - 8813
(2021/05/26)
-
- Systematic Study on the Catalytic Arsa-Wittig Reaction
-
Efficient catalytic arsa-Wittig reactions have been developed by using 1-phenylarsolane as a catalyst. A wide array of aldehydes was converted to the corresponding olefins in high yields with moderate to excellent E stereoselectivity in the presence of a catalytic amount of 1-phenylarsolane. Moreover, density functional theory calculations were carried out to afford insight into the E/Z selectivity.
- Inaba, Ryoto,Kawashima, Ikuo,Fujii, Toshiki,Yumura, Takashi,Imoto, Hiroaki,Naka, Kensuke
-
supporting information
p. 13400 - 13407
(2020/09/21)
-
- Selective Synthesis of Z-Cinnamyl Ethers and Cinnamyl Alcohols through Visible Light-Promoted Photocatalytic E to Z Isomerization
-
A photocatalytic E to Z isomerization of alkenes using an iridium photosensitizer under mild reaction conditions is disclosed. This method provides scalable and efficient access to Z-cinnamyl ether and allylic alcohol derivatives in high yields with excellent stereoselectivity. Importantly, this method also provides a powerful strategy for the selective synthesis of Z-magnolol and honokiol derivatives possessing potential biological activity.
- Li, Hengchao,Chen, Hang,Zhou, Yang,Huang, Jin,Yi, Jundan,Zhao, Hongcai,Wang, Wei,Jing, Linhai
-
supporting information
p. 555 - 559
(2020/02/05)
-
- Tandem Copper-Catalyzed Regioselective N-Arylation-Aza-Michael Addition: Synthesis of Tetracyclic 5 H-Benzothiazolo[3,2- a]quinazoline Derivatives
-
A copper-catalyzed tandem process integrating regioselective N-arylation, followed by aza-Michael addition, is disclosed using 2-aminobenzothiazoles and ortho-halo cinnamic acid congeners. This process generated diverse tetracyclic 5H-benzothiazolo[3,2-a]quinazoline derivatives in moderate to good yields. The present tandem reaction appears to proceed through concomitant ring opening of 2-aminobenzothiazole and S-arylation to give the ortho-cyanamide-substituted diaryl thioether intermediate. The thus generated intermediate likely undergoes an unprecedented Truce-Smiles-type rearrangement involving S- to N-aryl migration, followed by reformation of the thiazole ring and intramolecular aza-Michael addition to furnish the title products.
- Honnanayakanavar, Jyoti M.,Harish, Battu,Nanubolu, Jagadeesh Babu,Suresh, Surisetti
-
supporting information
p. 8780 - 8791
(2020/08/28)
-
- Bis(imidazolium) chloride based on 1,2-phenylenediamine as efficient ligand precursor for palladium-catalyzed Mizoroki-Heck cross-coupling reaction
-
Bis(imidazolium) chlorides based on 1,2-phenylenediamine were introduced as efficient ligand precursors in the Pd-catalyzed Mizoroki-Heck cross-coupling reactions of substituted aryl halides with activated alkenes to afford the corresponding functionalized alkenes. While high to excellent yields (78–96%) were obtained with aryl bromides, moderate yields (51–59%) were achieved for aryl chlorides in this protocol.
- Takallou, Ahmad,Habibi, Azizollah,Halimehjani, Azim Ziyaei,Balalaie, Saeed
-
supporting information
p. 24 - 28
(2019/03/21)
-
- Boron-Catalyzed C?C Functionalization of Allyl Alcohols
-
Tris(pentafluorophenyl)borane-catalyzed C?C bond functionalization of arylallyl alcohols using donor-acceptor carbenes is presented. The allylic hydroxyl group is found to assist the product formation by neighboring group participation providing a clue towards mechanistic understanding. This method can also be employed to effect homologation of allyl alcohols to homoallyl alcohols. Overall, this metal-free transformation presents a novel disconnection strategy towards carbon-carbon bond scission and formation. (Figure presented.).
- Rao, Santhosh,Kapanaiah, Raja,Prabhu, Kandikere Ramaiah
-
supporting information
(2019/02/14)
-
- Synthesis of Substituted β-Functionalised Styrenes by Microwave-Assisted Olefin Cross-Metathesis and Scalable Synthesis of Apremilast
-
Preparation of diversely substituted β-functionalised styrenes by microwave-assisted olefin cross-metathesis (CM) is described. This method can be also employed in the synthesis of β-deuterated α,β-unsaturated sulfones from inexpensive allylbenzenes, though unprecedented one-pot isomerisation/deuteration/cross-metathesis sequence. One of such obtained CM products has been utilised in a new scalable synthesis of Apremilast (6), a potent and orally active phosphodiesterase 4 and tumour necrosis factor-α inhibitor. The same strategy was used in synthesis of an optical antipode of 6, ent-Apremilast.
- Jana, Anupam,Zieliński, Grzegorz Krzysztof,Czarnocka-?niada?a, Sylwia,Grudzień, Krzysztof,Podwysocka, Dominika,Szulc, Marcin,Kajetanowicz, Anna,Grela, Karol
-
p. 5808 - 5813
(2019/11/03)
-
- Rh(III)-Catalyzed Enaminone-Directed C-H Coupling with α-Diazo-α-phosphonoacetate for Reactivity Discovery: Fluoride-Mediated Dephosphonation for C-C Coupling Reactions
-
Rh(III)-catalyzed enaminone-directed C-H coupling with α-diazo-α-phosphonoacetate has been used for the identification of fluoride-mediated dephosphonation C-C coupling reactivity for the synthesis of 4-hydroxy-1-naphthoates. Intermolecular C-C coupling of α-phosphonoacetate and benzaldehyde for (E)-selective α,β-unsaturated ester synthesis has also been achieved.
- Song, Chao,Yang, Chen,Zeng, Hua,Zhang, Wenjing,Guo, Shan,Zhu, Jin
-
supporting information
p. 3819 - 3823
(2018/07/22)
-
- One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
-
A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
- Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
-
p. 107 - 118
(2017/09/28)
-
- Facile synthesis of α, β-unsaturated esters through a one-pot copper-catalyzed aerobic oxidation-Wittig reaction
-
An efficient one-pot synthesis of α, β-unsaturated esters through the aerobic oxidation – Wittig tandem reaction of alcohols and phosphorous ylide is developed. This new method operates under mild reaction conditions, and uses CuI/TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) as co-catalyst and air (O2) as the oxidant. It tolerates a wide range of functionalized benzylic alcohol and aliphatic alcohols.
- Ren, Cheng,Shi, Zhenyu,Ding, Weijie,Liu, Zhiqing,Jin, Huile,Yu, Xiaochun,Wang, Shun
-
supporting information
p. 14 - 17
(2017/12/06)
-
- Bu 4 N + -Controlled Addition and Olefination with Ethyl 2-(Trimethylsilyl)acetate via Silicon Activation
-
Catalytic Bu 4 NOAc as silicon activator of ethyl 2-(trimethylsilyl)acetate, in THF, was utilized for the synthesis of β-hydroxy esters, whereas employing catalytic Bu 4 NOTMS gave α,β-unsaturated esters. The established reaction conditions were applicable to a diverse range of aromatic, heteroaromatic, aliphatic aldehydes and ketones. Reactions were achieved at room temperature without taking any of the specialized precautions that are in place for other organometallics. A stepwise olefination pathway via silylated β-hydroxy esters with subsequent elimination to form the α,β-unsaturated ester has been demonstrated. The key to selective product formation lies in use of the weaker acetate activator which suppresses subsequent elimination whereas stronger TMSO - activator (and base) facilitates both addition and elimination steps. The use of tetrabutyl ammonium salts for both acetate and trimethylsilyloxide activators provide enhanced silicon activation when compared to their inorganic cation counterparts.
- Das, Manas,Manvar, Atul,Fox, Ian,Roberts, Dilwyn J.,O'Shea, Donal F.
-
supporting information
p. 2401 - 2406
(2017/09/30)
-
- Ligand-accelerated non-directed C-H functionalization of arenes
-
The directed activation of carbon-hydrogen bonds (C-H) is important in the development of synthetically useful reactions, owing to the proximity-induced reactivity and selectivity that is enabled by coordinating functional groups. Palladium-catalysed non-directed C-H activation could potentially enable further useful reactions, because it can reach more distant sites and be applied to substrates that do not contain appropriate directing groups; however, its development has faced substantial challenges associated with the lack of sufficiently active palladium catalysts. Currently used palladium catalysts are reactive only with electron-rich arenes, unless an excess of arene is used, which limits synthetic applications. Here we report a 2-pyridone ligand that binds to palladium and accelerates non-directed C-H functionalization with arene as the limiting reagent. This protocol is compatible with a broad range of aromatic substrates and we demonstrate direct functionalization of advanced synthetic intermediates, drug molecules and natural products that cannot be used in excessive quantities. We also developed C-H olefination and carboxylation protocols, demonstrating the applicability of our methodology to other transformations. The site selectivity in these transformations is governed by a combination of steric and electronic effects, with the pyridone ligand enhancing the influence of sterics on the selectivity, thus providing complementary selectivity to directed C-H functionalization.
- Wang, Peng,Verma, Pritha,Xia, Guoqin,Shi, Jun,Qiao, Jennifer X.,Tao, Shiwei,Cheng, Peter T. W.,Poss, Michael A.,Farmer, Marcus E.,Yeung, Kap-Sun,Yu, Jin-Quan
-
p. 489 - 493
(2017/11/28)
-
- Gold-Catalyzed [2,3]-Sigmatropic Rearrangement: Reaction of Aryl Allyl Alcohols with Diazo Compounds
-
A gold-catalyzed [2,3]-sigmatropic rearrangement reaction has been developed. The intermolecular rearrangement occurs between in situ generated donor-acceptor gold-carbenes and cinnamyl alcohols via tandem oxonium ylide formation. The desired rearranged product has been accomplished selectively over more conventional O-H insertion, cyclopropanation, cycloaddition, and C-H functionalization products under mild, open-air conditions. The scope of the work has been illustrated by synthesizing a new class of substrates that can be used for constructing complex molecular targets.
- Rao, Santhosh,Prabhu, Kandikere Ramaiah
-
supporting information
p. 846 - 849
(2017/02/26)
-
- Expanding the substrate scope of phenylalanine ammonia-lyase from: Petroselinum crispum towards styrylalanines
-
This study focuses on the expansion of the substrate scope of phenylalanine ammonia-lyase from Petroselinum crispum (PcPAL) towards the l-enantiomers of racemic styrylalanines rac-1a-d-which are less studied and synthetically challenging unnatural amino acids-by reshaping the aromatic binding pocket of the active site of PcPAL by point mutations. Ammonia elimination from l-styrylalanine (l-1a) catalyzed by non-mutated PcPAL (wt-PcPAL) took place with a 777-fold lower kcat/KM value than the deamination of the natural substrate, l-Phe. Computer modeling of the reactions catalyzed by wt-PcPAL indicated an unproductive and two major catalytically active conformations and detrimental interactions between the aromatic moiety of l-styrylalanine, l-1a, and the phenyl ring of the residue F137 in the aromatic binding region of the active site. Replacing the residue F137 by smaller hydrophobic residues resulted in a small mutant library (F137X-PcPAL, X being V, A, and G), from which F137V-PcPAL could transform l-styrylalanine with comparable activity to that of the wt-PcPAL with l-Phe. Furthermore, F137V-PcPAL showed superior catalytic efficiency in the ammonia elimination reaction of several racemic styrylalanine derivatives (rac-1a-d) providing access to d-1a-d by kinetic resolution, even though the d-enantiomers proved to be reversible inhibitors. The enhanced catalytic efficiency of F137V-PcPAL towards racemic styrylalanines rac-1a-d could be rationalized by molecular modeling, indicating the more relaxed enzyme-substrate complexes and the promotion of conformations with higher catalytic activities as the main reasons. Unfortunately, ammonia addition onto the corresponding styrylacrylates 2a-d failed with both wt-PcPAL and F137V-PcPAL. The low equilibrium constant of the ammonia addition, the poor ligand binding affinities of 2a-d, and the non-productive binding states of the unsaturated ligands 2a-d within the active sites of either wt-PcPAL or F137V-PcPAL-as indicated by molecular modeling-might be responsible for the inactivity of the PcPAL variants in the reverse reaction. Modeling predicted that the F137V mutation is beneficial for the KRs of 4-fluoro-, 4-cyano- and 4-bromostyrylalanines, but non-effective for the KR process of 4-trifluoromethylstyrylalanine.
- Bencze, László Csaba,Filip, Alina,Bánóczi, Gergely,To?a, Monica Ioana,Irimie, Florin Dan,Gellért, ákos,Poppe, László,Paizs, Csaba
-
supporting information
p. 3717 - 3727
(2017/07/07)
-
- Bioactivity and structure-activity relationship of cinnamic acid esters and their derivatives as potential antifungal agents for plant protection
-
A series of cinnamic acid esters and their derivatives were synthesized and evaluated for antifungal activities in vitro against four plant pathogenic fungi by using the mycelium growth rate method. Structure-activity relationship was derived also. Almost all of the compounds showed some inhibition activity on each of the fungi at 0.5 mM. Eight compounds showed the higher average activity with average EC50 values of 17.4-28.6 μg/mL for the fungi than kresoxim-methyl, a commercial fungicide standard, and ten compounds were much more active than commercial fungicide standards carbendazim against P. grisea or kresoxim-methyl against both P. grisea and Valsa Mali. Compounds C1 and C2 showed the higher activity with average EC50 values of 17.4 and 18.5 μg/mL and great potential for development of new plant antifungal agents. The structure-activity relationship analysis showed that both the substitution pattern of the phenyl ring and the alkyl group in the alcohol moiety significantly influences the activity. There exists complexly comprehensive effect between the substituents on the phenyl ring and the alkyl group in the alcohol moiety on the activity. Thus, cinnamic acid esters showed great potential the development of new antifungal agents for plant protection due to high activity, natural compounds or natural compound framework, simple structure, easy preparation, low-cost and environmentally friendly.
- Zhou, Kun,Chen, Dongdong,Li, Bin,Zhang, Bingyu,Miao, Fang,Zhou, Le
-
-
- Solvent-free, one-pot synthesis of α,β-unsaturated esters in the presence of a C3-symmetric arsine
-
An efficient synthesis of α, β-unsaturated esters is achieved via a one-pot reaction in the presence of a C3-symmetric arsine. The key advantages are the short reaction time, simple workup, mild reaction conditions, and high yields.
- Wang, Changqing,Yang, Liu,Zhou, Rong,Mei, Guangquan
-
supporting information
p. 1074 - 1079
(2016/07/16)
-
- Design, synthesis, and evaluation of 2-piperidone derivatives for the inhibition of β-amyloid aggregation and inflammation mediated neurotoxicity
-
A series of novel multipotent 2-piperidone derivatives were designed, synthesized and biologically evaluated as chemical agents for the treatment of Alzheimer's disease (AD). The results showed that most of the target compounds displayed significant potency to inhibit Aβ1-42 self-aggregation. Among them, compound 7q exhibited the best inhibition of Aβ1-42 self-aggregation (59.11% at 20 μM) in a concentration-dependent manner. Additionally, the compounds 6b, 7p and 7q as representatives were found to present anti-inflammation properties in lipopolysaccharide (LPS)-induced microglial BV-2 cells. They could effectively suppress the production of pro-inflammatory cytokines such as TNF-α, IL-1β and IL-6. Meanwhile, compound 7q could prevent the neuronal cell SH-SY5Y death by LPS-stimulated microglia cell activation mediated neurotoxicity. The molecular modeling studies demonstrated that compounds matched the pharmacophore well and had good predicted physicochemical properties and estimated IC50 values. Moreover, compound 7q exerted a good binding to the active site of myeloid differentiation factor 88 (MyD88) through the docking analysis and could interfere with its homodimerization or heterodimerization. Consequently, these compounds emerged as promising candidates for further development of novel multifunctional agents for AD treatment.
- Li, Lei,Chen, Ming,Jiang, Feng-Chao
-
p. 1853 - 1865
(2016/04/05)
-
- N-heterocyclic carbene-catalysed Peterson olefination reaction
-
N-heterocyclic carbenes (NHCs) have been utilised as highly efficient organocatalysts to catalyse Peterson olefination reaction of aldehydes with trimethylsilylketene ethyl trimethylsilyl acetal or fluoro(trimethylsilyl)ketene ethyl trimethylsilyl acetal to produce the corresponding functionalized olefines in 34-93% yields with excellent stereoselectivities.
- Wang, Ying,Du, Guang-Fen,Gu, Cheng-Zhi,Xing, Fen,Dai, Bin,He, Lin
-
p. 472 - 478
(2015/12/31)
-
- Tandem oxidation–Wittig reaction using nanocrystalline barium manganate (BaMnO4); an improved one-pot protocol
-
A one-pot, tandem oxidation–Wittig procedure has been developed in which the reacting components are generated in situ from alcohols, triphenyl phosphine, and ethyl bromoacetate using barium manganate as a mild oxidizing agent without the addition of an external base.
- Gholinejad, Mohammad,Firouzabadi, Habib,Bahrami, Maedeh,Nájera, Carmen
-
supporting information
p. 3773 - 3775
(2016/07/26)
-
- Using non-covalent interactions to direct regioselective 2+2 photocycloaddition within a macrocyclic cavitand
-
The relative orientation of guests within ternary inclusion complexes is governed by the host-guest and guest-guest supramolecular interactions. Selectivity in 2+2 photocycloaddition between two alkenes included within a macrocyclic cavitand (γ-cyclodextrin) can be controlled using non-covalent interactions. In this manuscript, we report cavitand-mediated control of regioselectivity between alkyl cinnamates using non-covalent interactions. Using this method, we have shown that regioselectivity can be switched completely from a head-to-head dimer to a head-to-tail dimer. The reactions were also stereoselective in most cases. Stoichiometry experiments were performed to explore relative stabilities of the complexes, which indicate that the ternary complex is more stable than others. Selectivity in the photocycloaddition reaction was also applied retrospectively to deduce intermolecular orientations. Time-dependent conversion study we performed indicates that the observed reactivity of alkenes is representative of the intermolecular orientations in the bulk of the complex medium. Experimental observations and computational studies were used to qualitatively understand the complex structures, and relative magnitudes of the weak interactions. The reactions of complexes were studied in slurry form, and the extent of reaction control suggests a solid-state-like behavior.
- Nguyen, Nga,Clements, Aspen Rae,Pattabiraman, Mahesh
-
p. 2433 - 2443
(2016/03/19)
-
- Ligand-Free Heck Reactions of Aryl Iodides: Significant Acceleration of the Rate through Visible Light Irradiation at Ambient Temperature
-
A mild Heck reaction of aryl iodides and olefins was realized by the cooperation of a palladium and a photoredox catalyst under the irradiation of visible light. This protocol works well to synthesize stilbenes with high Z/E ratios and (E)-cinnamates in the absence of ligands at ambient temperature. Control experiments revealed that palladium salt, visible light and photoredox catalyst were all crucial for the achievement of this cross-coupling under mild conditions. (Figure presented.).
- Zhang, Heng,Huang, Xueliang
-
supporting information
p. 3736 - 3742
(2016/12/16)
-
- A Simple and Efficient Access to Naphtho[b]furans by Claisen Rearrangement/Cyclization of Bromonaphthyl 3-Phenylallyl Ethers
-
A transition-metal-free Claisen rearrangement/cyclization reaction was developed for the synthesis of naphthofuran derivatives from bromonaphthyl 3-phenylallyl ethers. The nature of the base employed in this reaction plays an important role in determining the ratio for the formation of naphthofuran and naphthol products. By using K2CO3 as base and DMF as solvent, we have synthesized a variety of functionalized naphthofurans in good to high yields (49-92 %) and with satisfactory selectivities.
- Wang, Wei,Huang, Jin,Zhou, Rong,Jiang, Zhi-Jie,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
-
supporting information
p. 2442 - 2446
(2015/08/18)
-
- Iron(IV)-Corrole Catalyzed Stereoselective Olefination of Aldehydes with Ethyl Diazoacetate
-
Iron(IV)-corrole complexes were first investigated as catalysts for olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine. Efficient olefination of aromatic aldehydes with high trans-selectivity was observed, showing iron corrole is a new kind of promising catalyst for olefination reaction. Transformation of the phosphazine to ylide by iron(IV) corrole was proved to be the key step in the present system.
- Zou, Huai-Bo,Yang, Hong,Liu, Ze-Yu,Mahmood, Mian H.R.,Mei, Guang-Quan,Liu, Hai-Yang,Chang, Chi-Kwong
-
supporting information
p. 2791 - 2795
(2015/06/30)
-
- SYNTHESIS OF FUNCTIONALIZED AND UNFUNCTIONALIZED OLEFINS VIA CROSS AND RING-CLOSING METATHESIS
-
The invention is directed to the cross-metathesis and ring-closing metathesis reactions between geminal disubstituted olefins and terminal olefins, wherein the reaction employs a Ruthenium or Osmium metal carbene complex. Specifically, the invention relates to the synthesis of alpha-functionalized or unfunctionalized olefins via intermolecular cross-metathesis and intramolecular ring-closing metathesis using a ruthenium alkylidene complex. The catalysts preferably used in the invention are of the general formulawherein:M is ruthenium or osmium;X and Xare each independently an anionic ligand;L is a neutral electron donor ligand; and,R, RR, R, R, and Rare each independently hydrogen or a substituent selected from the group consisting of C1-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, aryl, C1-C20 carboxylate, C1-C20 alkoxy, C2-C20 alkenyloxy, C2-C20 alkynyloxy, aryloxy, C2-C20 alkoxycarbonyl, C1-C20 alkylthio, C1-C20 alkylsulfonyl and C1-C20 alkylsulfinyl.
- -
-
Paragraph 0020; 0025
(2015/11/09)
-
- Oxidative alkoxycarbonylation of terminal alkenes with carbazates
-
A range of terminal alkenes smoothly underwent palladium-catalyzed oxidative alkoxycarbonylation with carbazates under an oxygen atmosphere to afford structurally diverse α,β-unsaturated esters in moderate to good yields with excellent regioselectivity and E selectivity.
- Su, Yu-Han,Wu, Zhao,Tian, Shi-Kai
-
supporting information
p. 6528 - 6530
(2013/07/26)
-
- HETEROARYLS AND USES THEREOF
-
This invention provides compounds of formula IB: and also provides compounds of formulas ID, IIB, VB, and IIC: wherein HY, R1, R2, G5, G6, G7, G8, and G9 are as described in the specification. The compounds are inhibitors of VPS34 and/or PI3K and are thus useful for treating proliferative, inflammatory, or cardiovascular disorders.
- -
-
Paragraph 0931
(2013/07/05)
-
- Phosphine-functionalized magnetic nanoparticles (PFMN) as a magnetic recyclable phosphorus ligand: Preparation of its palladium(II) complex for Heck reaction of chloroarenes
-
In this study, magnetic nanoparticles (MNs) were functionalized using chlorodiphenylphosphine (ClPPh2) and phosphine-functionalized magnetic nanoparticles (PFMN) as a recyclable phosphorus ligand was obtained. Also, palladium(II) complex of PFMN ligand (Pd-PFMN) was prepared and its catalytic activity was evaluated in the Heck reaction of chloroarenes. The results revealed that, this new catalyst showed high catalytic activity in the Heck reaction of chloroarenes and this can be attributed to the high reactivity of Pd complex involving phosphorus ligands and dispersible ability of MNs in solution as a high surface area support.
- Khalafi-Nezhad, Ali,Panahi, Farhad
-
-
- Unequivocal experimental evidence for a unified lithium salt-free wittig reaction mechanism for all phosphonium ylide types: Reactions with β-heteroatom-substituted aldehydes are consistently selective for cis-oxaphosphetane-derived products
-
The true course of the lithium salt-free Wittig reaction has long been a contentious issue in organic chemistry. Herein we report an experimental effect that is common to the Wittig reactions of all of the three major phosphonium ylide classes (non-stabilized, semi-stabilized, and stabilized): there is consistently increased selectivity for cis-oxaphosphetane and its derived products (Z-alkene and erythro-β-hydroxyphosphonium salt) in reactions involving aldehydes bearing heteroatom substituents in the β-position. The effect operates with both benzaldehydes and aliphatic aldehydes and is shown not to operate in the absence of the heteroatom substituent on the aldehyde. The discovery of an effect that is common to reactions of all ylide types strongly argues for the operation of a common mechanism in all Li salt-free Wittig reactions. In addition, the results are shown to be most easily explained by the [2+2] cycloaddition mechanism proposed by Vedejs and co-workers as supplemented by Aggarwal, Harvey, and co-workers, thus providing strong confirmatory evidence in support of that mechanism. Notably, a cooperative effect of ortho-substituents in the case of semi-stabilized ylides is confirmed and is accommodated by the cycloaddition mechanism. The effect is also shown to operate in reactions of triphenylphosphine-derived ylides and has previously been observed for reactions under aqueous conditions, thus for the first time providing evidence that kinetic control is in operation in both of these cases.
- Byrne, Peter A.,Gilheany, Declan G.
-
supporting information; experimental part
p. 9225 - 9239
(2012/07/14)
-
- Palladium-catalyzed double arylations of terminal olefins in acetic acid
-
A palladium-catalyzed Heck diarylation of terminal olefins under ligand-free conditions in acetic acid is described. This procedure allows double arylation of terminal olefins affording trisubstituted olefins in good to excellent yields. The methodology is applicable to the coupling of both electron-deficient and electron-rich aryl iodides leading to symmetrical and unsymmetrical β,β-diarylated alkenes.
- Xu, Daichao,Lu, Chunxin,Chen, Wanzhi
-
experimental part
p. 1466 - 1474
(2012/03/08)
-
- A newly-designed PE-supported arsine for efficient and practical catalytic Wittig olefination
-
A newly designed PE-supported arsine has been developed as an excellent catalyst for catalytic Wittig-type olefination. Simple ketones, in particular inactive ketones prove to be suitable substrates for the first time. This reaction provides an easy access to di-, tri-, and tetra-substituted olefins in high yield.
- Wang, Peng,Liu, Chun-Rong,Sun, Xiu-Li,Chen, Shuai-Shuai,Li, Jun-Fang,Xie, Zuowei,Tang, Yong
-
supporting information; experimental part
p. 290 - 292
(2012/01/06)
-
- Synthesis of 1,3,5-trisubstituted pyrazolines via Zn(ii)-catalyzed double hydroamination of enynes with aryl hydrazines
-
An efficient Zn(ii)-catalyzed intermolecular double hydroamination of 1,3-enynes with aryl hydrazines, for the synthesis of pyrazolines, has been discussed.
- Patil, Nitin T.,Singh, Vipender
-
supporting information; experimental part
p. 11116 - 11118
(2011/11/29)
-
- One-pot synthesis of α,β-unsaturated esters promoted by sodium hydride
-
A new protocol for the synthesis of α,β-unsaturated esters was described with various aldehydes and ethyl acetate in presence of sodium hydride. Advantage of this method is high efficiency, shorter time period and inexpensive.
- Swetha,Venkata Ramana,Shirodkar
-
experimental part
p. 522 - 524
(2011/12/15)
-
- An efficient synthesis of poly(ethylene glycol)-supported iron(II) porphyrin using a click reaction and its application for the catalytic olefination of aldehydes
-
The first successful synthesis of poly(ethylene glycol) (PEG) immobilized iron(II) porphyrin using a copper-catalyzed azide-alkyne [3+2] cycloaddition is reported. In contrast to the existing methods for the synthesis of PEG-immobilized metalloporphyrins, the click method offers better catalyst loading under comparatively mild reaction conditions. The prepared complex 5 (PEG-C51H39FeN7O) was found to be an efficient catalyst for the selective olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine and afforded excellent olefin yields with high (E) selectivities. The PEG-supported catalyst 5 was readily recovered by precipitation and filtration and was recycled for up to ten runs without significant loss of activity.
- Jain, Suman L.,Joseph, Jomy K.,Kuehn, Fritz E.,Reiser, Oliver
-
supporting information; experimental part
p. 230 - 234
(2009/09/06)
-
- A convenient method for the lewis base-catalyzed synthesis of α,β-unsaturated carboxylic esters using trimethylsilylketene ethyl trimethylsilyl acetal and carbonyl compounds
-
A highly useful method for the synthesis of α,β-unsaturated carboxylic esters from various carbonyl compounds that uses trimethylsilylbetene ethyl trimethylsilyl acetal in the presence of a Lewis base catalyst such as acetate salts was established. This procedure gives the corresponding esters in high yields with excellent E stereoselectivity under mild conditions. Copyright
- Michida, Makoto,Mukaiyama, Teruaki
-
p. 704 - 705
(2008/12/21)
-
- A novel Heck reaction catalyzed by Co hollow nanospheres in ligand-free condition
-
Heck reaction catalyzed by cobalt hollow nanospheres has been developed; the coupling of alkenes with aryl iodide or aryl bromide in the presence of potassium carbonate provides the corresponding products with moderate to good yields, which reveals obvious advantages such as low-cost catalyst, ligand-free condition, the recyclability of the catalyst and simple experimental operation. The Royal Society of Chemistry.
- Zhou, Ping,Li, Yingguang,Sun, Peipei,Zhou, Jiahong,Bao, Jianchun
-
p. 1418 - 1420
(2008/02/02)
-
- The one-pot Wittig reaction: A facile synthesis of α,β- unsaturated esters and nitriles by using nanocrystalline magnesium oxide
-
Nanocrystalline magnesium oxide was found to be an effective heterogeneous, solid base catalyst for the one-pot Wittig reaction to afford α,β-unsaturated esters and nitriles in excellent yields with high E-stereoselectivity in the presence of triphenylphosphine under mild conditions.
- Choudary, Boyapati M.,Mahendar, Koosam,Kantam, M. Lakshmi,Ranganath, Kalluri V. S.,Athar, Taimur
-
p. 1977 - 1985
(2007/10/03)
-
- Ethyl (benzothiazol-2-ylsulfonyl)acetate: A new reagent for the stereoselective synthesis of α,β-unsaturated esters from aldehydes
-
The title reagent engaged in the modified Julia olefination with aldehydes under mild reaction conditions (DBU, CH2Cl2, rt or -78°C) to yield α,β-unsaturated esters; aryl aldehydes and aliphatic aldehydes possessing significant chain branching elements gave trans alkene products with high stereoselectivity (E : Z up to >98 : 2), while straight chain aliphatic aldehydes gave cis products preferentially (Z : E up to 92 : 8). The Royal Society of Chemistry 2095.
- Blakemore, Paul R.,Ho, Danny K.H.,Nap, W. Mieke
-
p. 1365 - 1368
(2007/10/03)
-
- Pd(OAc)2-Catalyzed Oxidative Coupling Reaction of Benzenes with Olefins in the Presence of Molybdovanadophosphoric Acid under Atmospheric Dioxygen and Air
-
The direct oxidative coupling reaction of benzenes with alkenes bearing an electron-withdrawing group was successfully achieved by the use of Pd(OAc) 2/molybdovanadophosphoric acid (HPMoV) as the key catalyst under O2 or air atmosphere. Thus, the reaction of benzene with ethyl acrylate under air (1 atm) assisted by Pd(OAc)2/HPMoV afforded ethyl cinnamate as a major product in satisfactory yield (74%). This catalytic system could be extended to the coupling reactions between various substituted benzenes and alkenes through the direct aromatic C-H bond activation. In the reaction of benzene with ethyl acrylate under O2 (1 atm), the best turn-over number (TON) of Pd(OAc)2 reached was 121. This reaction provides a green route to cinnamate derivatives, which are important precursors of a variety of pharmaceuticals.
- Tani, Masayuki,Sakaguchi, Satoshi,Ishii, Yasutaka
-
p. 1221 - 1226
(2007/10/03)
-
- A general model for selectivity in olefin cross metathesis
-
In recent years, olefin cross metathesis (CM) has emerged as a powerful and convenient synthetic technique in organic chemistry; however, as a general synthetic method, CM has been limited by the lack of predictability in product selectivity and stereoselectivity. Investigations into olefin cross metathesis with several classes of olefins, including substituted and functionalized styrenes, secondary allylic alcohols, tertiary allylic alcohols, and olefins with α-quaternary centers, have led to a general model useful for the prediction of product selectivity and stereoselectivity in cross metathesis. As a general ranking of olefin reactivity in CM, olefins can be categorized by their relative abilities to undergo homodimerization via cross metathesis and the susceptibility of their homodimers toward secondary metathesis reactions. When an olefin of high reactivity is reacted with an olefin of lower reactivity (sterically bulky, electron-deficient, etc.), selective cross metathesis can be achieved using feedstock stoichiometries as low as 1:1. By employing a metathesis catalyst with the appropriate activity, selective cross metathesis reactions can be achieved with a wide variety of electron-rich, electron-deficient, and sterically bulky olefins. Application of this model has allowed for the prediction and development of selective cross metathesis reactions, culminating in unprecedented three-component intermolecular cross metathesis reactions.
- Chatterjee, Arnab K.,Choi, Tae-Lim,Sanders, Daniel P.,Grubbs, Robert H.
-
p. 11360 - 11370
(2007/10/03)
-
- Direct coupling of benzene with olefin catalyzed by Pd(OAc)2 combined with heteropolyoxometalate under dioxygen
-
The oxidative coupling reaction of benzenes with alkenes was successfully achieved by the Pd(OAc)2/molybdovanadophosphoric acid (HPMoV)/O2 system. For example, the reaction of benzene with ethyl acrylate by the above catalytic system in acetic acid afforded ethyl cinnamate as a major product in satisfactory yield. Copyright
- Yokota, Takahiro,Tani, Masayuki,Sakaguchi, Satoshi,Ishii, Yasutaka
-
p. 1476 - 1477
(2007/10/03)
-
- Unexpected catalyst for Wittig-type and dehalogenation reactions
-
A novel catalyst 2 for Wittig-type and dehalogenation reactions was developed. In the presence of triphenyl phosphite, a wide variety of aldehydes could react with α-bromoacetates to afford α,β-unsaturated esters or ketones in high yields with excellent E-stereoselectivity when 1-2 mol % of compound 2 was used. Compound 2 was also an effective catalyst for reductive dehalogenation of α-bromocarbonyl compounds. The mechanisms for the above reactions were also proposed.
- Huang, Zheng-Zheng,Tang, Yong
-
p. 5320 - 5326
(2007/10/03)
-
- Polymer-assisted Horner-Emmons olefination using PASSflow reactors: pure products without purification.
-
A PASSflow protocol for the Horner-Emmons olefination of aldehydes using polymer-bound hydroxide ions in flowthrough reactors is presented which allows preparation of alkenes in very high yield with minimal purification.
- Solodenko, Wladimir,Kunz, Ulrich,Jas, Gerhard,Kirschning, Andreas
-
p. 1833 - 1835
(2007/10/03)
-
- Inhibition of uridine phosphorylase: Synthesis and structure-activity relationships of aryl-substituted 5-benzyluracils and 1-[(2- hydroxyethoxy)methyl]-5-benzyluracils
-
A series of 1-[(2-hydroxyethoxy)methyl]-5-benzyluracils were synthesized and tested for inhibition of murine liver uridine phosphorylase (UrdPase). Inhibitors of UrdPase are reported to enhance the chemotherapeutic utility of 5-fluoro-2'-deoxyuridine and 5-fluorouracil and to ameliorate zidovudine- induced anemia in animal models. We prepared a series of 5-aryl-substituted analogues of 5-benzylacyclouridine (BAU), a good inhibitor of UrdPase (IC50 of 0.46 μM), to develop a compound with enhanced potency and improved pharmacokinetics. The first phase of structure-activity relationship studies on a series of 32 aryl-substituted 5-benzyluracils found several 5-(3- alkoxybenzyl) analogues of 5-benzyluracil with enhanced potency. The acyclovir side chain, the (2-hydroxyethoxy)methyl group, was substituted on the more potent aryl-substituted 5-benzyluracils. The two most potent compounds, 10y (3-propoxy) and 10dd (3-sec-butoxy), were inhibitors of UrdPase with IC50s of 0.047 and 0.027 μM, respectively. Six compounds were tested in vivo for effects on steady-state concentrations of circulating uridine in rats. Plasma uridine levels were elevated 3-9-fold by compound levels that ranged from 8 to 50 μM.
- Orr,Musso,Boswell,Kelley,Joyner,Davis,Baccanari
-
p. 3850 - 3856
(2007/10/02)
-
- Palladium-catalyzed Reaction of Phenyl Fluoroalkanesulfonates with Alkynes and Alkenes
-
Palladium-catalyzed reaction of phenyl fluoroalkanesulfonates with alkynes and alkens under mild conditions gives the corresponding alkynyl and alkenyl substituted benzenes in good yields.
- Chen, Qing-Yun,Yang, Zhen-Yu
-
p. 1171 - 1174
(2007/10/02)
-
- SYNTHESE TOTALE DE STEROIDES A CYCLE C AROMATIQUE
-
The ring-C aromatic analogue 4 of 4-androstene 3,17-dione and its 11 hydroxylated(methoxylated) derivatives 20a(b) were prepared by a practical synthetic route.The key steps of the sequence are achieved in superacid: the cyclisation of diarylethane 5a to phenanthrenone 17, and the hydroxylation by hydrogenperoxide of ketone 4 to phenol 20a.
- Berrier, C.,Gesson, J. P.,Jacquesy, J. C.,Renoux, A.
-
p. 4973 - 4980
(2007/10/02)
-
- THE PALLADIUM-CATALYSED ARYLATION OF ACTIVATED ALKENES WITH AROYL CHLORIDES
-
Aroyl chlorides react with activated alkenes in presence of a tertiary amine and a catalytic amount of palladium acetate to give arylated alkenes, specifically cinnamic acid derivatives and stilbenes.The reaction involves a highly efficient decarbonylation of the aroyl chloride.High yields can be obtained at low catalyst concentration by choice of an appropriate base.The reaction is not particularly sensitive to substituents in the aroyl chloride, although strongly electron-donating groups are advantagenous (yields up to 98percent).With monosubstituted alkenes E-isomers are formed with almost complete specificity.A mechanism for the reaction is proposed.
- Blaser, Hans-Ulrich,Spencer, Alwyn
-
p. 267 - 274
(2007/10/02)
-
- Process for the preparation of alkenylbenzenecarboxylic acid derivatives and alkenylnaphthalenecarboxylic acid derivatives
-
Compounds of the formula I STR1 in which p, m, Z, R, R' and Y are as defined in claim 1, can be obtained in a simple and economical manner by a novel process which comprises reacting a halide of the formula STR2 with the corresponding acrylic acid derivative, in the presence of a base and of certain palladium catalysts, such as palladium acetate. The compounds (I), and functional derivatives prepared therefrom, are useful for the preparation of photocrosslinkable polymers, which can in particular be employed as (so-called) photoresists.
- -
-
-