- Crossed Regio- and Enantioselective Iron-Catalyzed [4+2]-Cycloadditions of Unactivated Dienes
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The cyclohexene motif is ubiquitous in nature and specialty chemicals. A straightforward selective access to chiral cyclohexenes from unactivated dienes and dienophiles is not feasible by classical Diels–Alder reaction and constitutes an unsolved syntheti
- Braconi, Elena,Cramer, Nicolai
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supporting information
(2021/12/22)
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- Method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and diphosphine ligand used in method
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The invention discloses a method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and a diphosphine ligand used in the method. According to the invention, indole-substituted phosphoramidite diphosphine ligand which is stable in air and insensitive to light is synthesized by utilizing a continuous one-pot method, and the indole-substituted phosphoramidite diphosphine ligand and a rhodium catalyst are used for jointly catalyzing to successfully achieve a hydroformylation reaction of aromatic terminal alkyne and terminal conjugated eneyne under the condition of synthesis gas for the first time, so that an olefine aldehyde structure compound can be rapidly and massively prepared, and particularly, a polyolefine aldehyde structure compound which is more difficult to synthesize in the prior art can be easily prepared and synthesized, and a novel method is provided for synthesis and modification of drug molecules, intermediates and chemical products.
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Paragraph 0163; 0164
(2021/05/29)
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- Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
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The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.
- Zhao, Jiangui,Zheng, Xueli,Tao, Shaokun,Zhu, Yuxin,Yi, Jiwei,Tang, Songbai,Li, Ruixiang,Chen, Hua,Fu, Haiyan,Yuan, Maolin
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supporting information
p. 6067 - 6072
(2021/08/16)
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- One-Pot Preparation of (E)-α,β-Unsaturated Aldehydes by a Julia-Kocienski Reaction of 2,2-Dimethoxyethyl PT Sulfone Followed by Acid Hydrolysis
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(E)-α,β-Unsaturated aldehydes were synthesized by the Julia-Kocienski reaction of 2,2-dimethoxyethyl 1-phenyl-1H-tetrazol-5-yl (PT) sulfone 3 with various aldehydes, followed by acid hydrolysis. The reaction could be carried out in one pot, and various (E)-α,β-unsaturated aldehydes were obtained in a short time and with high yields.
- Ando, Kaori,Watanabe, Haruka,Zhu, Xiaoxian
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p. 6969 - 6973
(2021/05/06)
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- Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
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A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
- Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
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supporting information
p. 3173 - 3180
(2021/04/21)
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- Highly γ-Regioselective 1,2-Addition of α,β-Unsaturated Oxime Ethers with Allylzinc Bromides: A Straightforward Approach for the Synthesis of Homoallylic Amines
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A highly regioselective reaction between allylzinc bromide reagents and α,β-unsaturated oxime ethers for the one-step synthesis of the homoallylic amines is reported. This process is a regioselective 1,2-addition reaction providing a new γ-position with carbon-carbon bond formation. Furthermore, the reaction substrates are widely applicable and can be produced in a high yield.
- Yang, Bo,Zhang, Songlin
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supporting information
p. 3736 - 3746
(2019/09/30)
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- Enantioselective Organocatalytic Enamine C?H Oxidation/Diels- Alder Reaction
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α,β-unsaturated aldehydes have been traditionally used in LUMO lowering asymmetric aminocatalysis (iminium catalysis), while the use of saturated aldehydes as substrates in this type of catalysis has been elusive, until recently. Herein, we demonstrate that organic, single-electron oxidants in the presence of diarylprolinol silylether type catalysts serve as effective tools for the transformation of electron rich enamines to iminium ions which partake in a subsequent Diels-Alder reaction. This enantioselective one-pot transformation represents the first example of saturated aldehydes being used in domino Diels-Alder reaction processes and demonstrates the power of this protocol for construction of stereo-defined chiral compounds and building blocks. (Figure presented.).
- D?ambaski, Zdravko,Tzaras, Dimitrios-Ioannis,Lee, Sunggi,Kokotos, Christoforos G.,Bondzic, Bojan P.
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supporting information
p. 1792 - 1797
(2019/02/25)
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- Lipase/Oxovanadium Co-Catalyzed Dynamic Kinetic Resolution of Propargyl Alcohols: Competition between Racemization and Rearrangement
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Quantitative conversion of racemic propargyl alcohols into optically active propargyl esters with up to 99% ee has been achieved by lipase/oxovanadium co-catalyzed dynamic kinetic resolution, which combines the lipase-catalyzed enantioselective esterification of the racemic substrates and the in situ racemization of the remaining enantiomers. The success is owed to our discovery of a magic solvent, (trifluoromethyl)benzene, that accelerated the racemization while sufficiently suppressing the common oxovanadium-catalyzed rearrangement of propargyl alcohols to irreversibly produce enals.
- Kawanishi, Shinji,Oki, Shinya,Kundu, Dhiman,Akai, Shuji
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supporting information
p. 2978 - 2982
(2019/03/26)
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- Highly Enantioselective Synthesis of Functionalized Glutarimide Using Oxidative N-Heterocyclic Carbene Catalysis: A Formal Synthesis of (?)-Paroxetine
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A simple yet highly effective approach toward enantioselective synthesis of trans-3,4-disubstituted glutarimides from readily available starting materials is developed using oxidative N-heterocyclic carbene catalysis. The catalytic reaction involves a formal [3 + 3] annulation between enals and substituted malonamides enabling the production of glutarimide derivatives in a single chemical operation via concomitant formation of C-C and C-N bonds. The reaction offers easy access to a broad range of functionalized glutarimides with excellent enantioselectivity and good yield. Synthetic application of the method is demonstrated via formal synthesis of (?)-paroxetine and other bioactive molecules.
- Porey, Arka,Santra, Surojit,Guin, Joyram
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supporting information
p. 5313 - 5327
(2019/04/16)
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- NOVEL COMPOUND HAVING AUXIN BIOSYNTHESIS INHIBITORY ACTIVITY, MANUFACTURING METHOD THEREFOR AND APPLICATION THEREOF
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PROBLEM TO BE SOLVED: To provide a novel compound having an auxin biosynthesis inhibitory activity, and a novel compound having the auxin biosynthesis inhibitory activity with different mechanism of action from conventional auxin biosynthesis inhibitors. SOLUTION: An aspect of the invention relates to a compound represented by the formula (I), wherein n, Ar, A, X1, X2, R1, R2, R3, R4, R5, R6, R7, R8, and R9 have meaning described in the application and the Claims, or a salt thereof, or a solvate thereof. Another aspect of the invention relates to an auxin biosynthesis inhibitors containing the compound represented by the formula (I), or a salt thereof, or a solvate thereof as active ingredients, agricultural applications of the compound, and a manufacturing method of the compound. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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- Palladium-catalyzed allylic C-H oxidation under simple operation and mild conditions
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We discovered an effective and simple system (Pd/BQ/air/r.t.) for making allylic alcohols through Pd-catalyzed allylic C-H bond functionalization. This approach exhibits advantages due to its simple operation, mild conditions, and environmentally benign features. By modifying reaction conditions, it can be suitable for preparing unsaturated aldehydes, allylic esters, ethers, and amines.
- Guo, Yunlong,Shen, Zengming
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supporting information
p. 3103 - 3107
(2019/03/26)
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- Phosphorous acid promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction.
- Gan, Xiaotang,Fu, Zuqi,Liu,Yan, Yani,Chen, Chao,Zhou, Yongbo,Dong, Jianyu
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- Palladium-Catalyzed Cascade Double C—N Bond Activation: A New Strategy for Aminomethylation of 1,3-Dienes with Aminals
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A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminals via double C—N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear α,β-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C—N bond to furnish a cascade double C—N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C—N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C—N bond activation of the allylic diamines.
- Qiao, Cuifang,Chen, Anrong,Gao, Bingjian,Liu, Yang,Huang, Hanmin
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supporting information
p. 929 - 933
(2018/09/22)
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- Copper-catalyzed formylation of alkenyl C-H bonds using BrCHCl2 as a stoichiometric formylating reagent
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The first example of copper-catalyzed direct formylation of alkenyl C-H bonds for the facile synthesis of α,β-unsaturated aldehydes has been developed. This transformation has demonstrated high reactivity, mild reaction conditions and a broad substrate scope. BrCHCl2 is expected to be developed as an efficient stoichiometric C1 building block in organic synthesis.
- Bao, Yan,Wang, Gao-Yin,Zhang, Ya-Xuan,Bian, Kang-Jie,Wang, Xi-Sheng
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p. 2986 - 2990
(2018/03/23)
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- Palladium-Catalyzed Formylation of Alkenylzinc Reagents with S-(4-Nitrophenyl) Thioformate
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We report the synthesis of enal compounds by palladium-catalyzed formylation of alkenylzinc reagents with S-(4-nitrophenyl) thioformate. Various functional groups were tolerated in the present reaction. 1H NMR experiments revealed that the products had a non-protected formyl group, which can be utilized for further C–C bond formation reactions. We successfully achieved the one-pot synthesis of a 1,5-diene-3-ol compound via sequential formylation and allylation.
- Haraguchi, Ryosuke,Tanazawa, Sho-Go,Tokunaga, Naoya,Fukuzawa, Shin-Ichi
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p. 1761 - 1764
(2018/04/27)
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- Palladium-catalyzed hydroformylation of terminal arylacetylenes with glyoxylic acid
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A simple, practical and governable palladium-catalyzed hydroformylation of terminal arylacetylenes has been disclosed. The reaction proceeds under syngas-free conditions, using readily available glyoxylic acid as the formyl source, under mild conditions, giving rise to a broad range of α,β-unsaturated aldehydes.
- Liu, Yang,Cai, Liangzhen,Xu, Sheng,Pu, Weiwen,Tao, Xiaochun
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supporting information
p. 2166 - 2168
(2018/03/06)
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- Discovery of novel piperonyl derivatives as diapophytoene desaturase inhibitors for the treatment of methicillin-, vancomycin- and linezolid-resistant Staphylococcus aureus infections
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Inhibition of S. aureus diapophytoene desaturase (CrtN) could serve as an alternative approach for addressing the tricky antibiotic resistance by blocking the biosynthesis of carotenoid pigment which shields the bacterium from host oxidant killing. In this study, we designed and synthesized 44 derivatives with piperonyl scaffold targeting CrtN and the structure-activity relationships (SARs) were examined extensively to bring out the discovery of 21b with potent efficacy and better hERG safety profile compared to the first class CrtN inhibitor benzocycloalkane derivative 2. Except the excellent pigment inhibitory activity against wild-type S. aureus, 21b also showed excellent pigment inhibition against four pigmented MRSA strains. In addition, H2O2 killing and human whole blood killing assays proved 21b could sensitize S. aureus to be killed under oxidative stress conditions. Notably, the murine study in vivo validated the efficacy of 21b against pigmented S. aureus Newman, vancomycin-intermediate S. aureus Mu50 and linezolid-resistant S. aureus NRS271.
- Wei, Hanwen,Mao, Fei,Ni, Shuaishuai,Chen, Feifei,Li, Baoli,Qiu, Xiaoxia,Hu, Linghao,Wang, Manjiong,Zheng, Xinyu,Zhu, Jin,Lan, Lefu,Li, Jian
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p. 235 - 251
(2018/01/17)
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- An Efficient and Practical Method for the Enantioselective Synthesis of Tertiary Trifluoromethyl Carbinols
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An efficient sulfinamide/olefin based chiral ligand, MetSulfolefin, has been developed for the enantioselective rhodium-catalysed addition of aryl-boronic acids to trifluoromethyl ketones. This shelf-stable ligand is insensitive to air, oxygen and moisture, and it is obtained in only two high yielding steps from cheap commercially available (R)-tert-butanesulfinamide. The new ligand tolerates the use of hindered boronic acids and leads to the formation of a series of chiral trifluoromethyl-substituted tertiary carbinols in high yields and excellent enantioselectivities (up to >99% ee). (Figure presented.).
- Borrego, Lorenzo G.,Recio, Rocío,Alcarranza, Manuel,Khiar, Noureddine,Fernández, Inmaculada
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supporting information
p. 1273 - 1279
(2018/02/14)
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- One-Pot l-Proline-Mediated Stereoselective α-C(sp2)–H Fluorination of α,β-Unsaturated Aldehydes through Methoxyfluorination–Elimination
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A one-pot, two-step l-proline-mediated stereoselective α-C(sp2)–H fluorination of α,β-unsaturated aldehydes towards their corresponding (Z)-α-fluoro-α,β-unsaturated aldehydes has been developed. The first step utilises Selectfluor as a fluorinating agent in CH3NO2/MeOH forming (Z)-α-fluoro-α,β-unsaturated aldehydes and their corresponding dimethyl acetals through methoxyfluorination-elimination. In the second step, water is added to promote the hydrolytic cleavage of the dimethyl acetals. The obtained (Z)-α-fluoro-α,β-unsaturated aldehydes were smoothly reduced to the corresponding alcohols by using NaBH4.
- Zhou, Jiadi,Jiang, Xinpeng,Jin, Can,Guo, Zhicheng,Su, Bin,Su, Weike
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supporting information
p. 3631 - 3634
(2017/07/22)
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- Novel Inhibitors of Staphyloxanthin Virulence Factor in Comparison with Linezolid and Vancomycin versus Methicillin-Resistant, Linezolid-Resistant, and Vancomycin-Intermediate Staphylococcus aureus Infections in Vivo
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Our previous work (Wang et al. J. Med. Chem. 2016, 59, 4831-4848) revealed that effective benzocycloalkane-derived staphyloxanthin inhibitors against methicillin-resistant Staphylococcus aureus (S. aureus) infections were accompanied by poor water solubility and high hERG inhibition and dosages (preadministration). In this study, 92 chroman and coumaran derivatives as novel inhibitors have been addressed for overcoming deficiencies above. Derivatives 69 and 105 displayed excellent pigment inhibitory activities and low hERG inhibition, along with improvement of solubility by salt type selection. The broad and significantly potent antibacterial spectra of 69 and 105 were displayed first with normal administration in the livers and hearts in mice against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate S. aureus), and NRS271 (linezolid-resistant S. aureus), compared with linezolid and vancomycin. In summary, both 69 and 105 have the potential to be developed as good antibacterial candidates targeting virulence factors.
- Ni, Shuaishuai,Wei, Hanwen,Li, Baoli,Chen, Feifei,Liu, Yifu,Chen, Wenhua,Xu, Yixiang,Qiu, Xiaoxia,Li, Xiaokang,Lu, Yanli,Liu, Wenwen,Hu, Linhao,Lin, Dazheng,Wang, Manjiong,Zheng, Xinyu,Mao, Fei,Zhu, Jin,Lan, Lefu,Li, Jian
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supporting information
p. 8145 - 8159
(2017/10/18)
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- Copper-catalyzed Mannich-type oxidative β-functionalization of tertiary amines
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A copper-catalyzed Mannich-type oxidative β-functionalization reaction of amines has been developed. In the presence of an oxidant and a copper catalyst, tertiary amines reacted with N-tosylimines, providing synthetically important 1,3-diamines and enamines, respectively. Preliminary mechanistic studies suggested that the oxidation of the tertiary amine to the enamine intermediate triggers subsequent Mannich-type reactions with N-tosylimines and thus enables the direct β-functionalization of the tertiary amines.
- Zhou, Min-Jie,Zhu, Shou-Fei,Zhou, Qi-Lin
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supporting information
p. 8770 - 8773
(2017/08/09)
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- Cascade reaction of propargylic alcohols with hydroxylamine hydrochloride: facile synthesis of α,β-unsaturated oximes and nitriles
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We have developed an easy and practical method for the synthesis of α,β-unsaturated oximes and nitriles from readily available propargylic alcohols with hydroxylamine hydrochloride (NH2OH·HCl) under metal-free conditions. By using or not using p-toluenesulfonyl chloride (p-TsCl) as the dehydrating promoter, the desired nitriles or oximes could be obtained, respectively via a three-step one-pot or two-step one-pot process in moderate to excellent yields with good functional group compatibility.
- Zhang, Qi,Zhang, Linjing,Tang, Chaojun,Luo, Huan,Cai, Xuediao,Chai, Yonghai
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p. 6935 - 6942
(2016/10/14)
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- One-Pot Synthesis of (S)-Baclofen via Aldol Condensation of Acetaldehyde with Diphenylprolinol Silyl Ether Mediated Asymmetric Michael Reaction as a Key Step
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An efficient asymmetric total synthesis of (S)-baclofen was accomplished via a one-pot operation from commercially available materials using sequential reactions, such as aldol condensation of acetaldehyde, diphenylprolinol silyl ether mediated asymmetric Michael reaction of nitromethane, Kraus-Pinnick oxidation, and Raney Ni reduction. Highly enantioenriched baclofen was obtained in one pot with a good yield over four reactions.
- Hayashi, Yujiro,Sakamoto, Daisuke,Okamura, Daichi
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supporting information
p. 4 - 7
(2016/01/15)
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- Expanding the scope of the Babler–Dauben oxidation: 1,3-oxidative transposition of secondary allylic alcohols
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We report the catalytic chromium-mediated oxidation of secondary allylic alcohols to give α,β-unsaturated aldehydes with exclusive (E)-stereoselectivity. This facile procedure employs catalytic PCC (5?mol?%) and periodic acid (H5IO6) as a co-oxidant. This transformation occurs specifically with aromatic substituted allyl alcohols containing both electron withdrawing and electron donating substituents as well as a range of functional groups.
- Killoran, Patrick M.,Rossington, Steven B.,Wilkinson, James A.,Hadfield, John A.
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supporting information
p. 3954 - 3957
(2016/08/09)
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- Preparation method of alpha-beta-unsaturated carbonyl compound
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The invention relates to a preparation method of an alpha-beta-unsaturated carbonyl compound, in particular to a method in which the alpha-beta-unsaturated carbonyl compound is prepared from substitute propargyl alcohol in a mode that positive ion modified imvite serves as a catalyst, the substitute propargyl alcohol serves as the raw material, and Meyer-Schuster rearrangement is utilized. According to the method, the substrate is wide in application range, the catalyst is cheap, easy to manufacture, stable, free of pollution to the environment and capable of being recycled, the reaction yield is high, stereoselectivity is good, and an E-type product can be obtained in a singular mode.
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Paragraph 0071; 0072; 0073; 0074; 0075; 0076; 0077; 0078
(2016/10/09)
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- Naphthalene and 2,3-dihydrobenzo[b][1,4]dioxine derivatives with extended side chains as new scaffolds of CB2-selective ligands
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Herein, we report the synthesis of naphthalene, dihydrobenzodioxine and fluorene derivatives with extended side chains and their biological evaluation as ligands of CB1 and CB2 receptors. Compounds 6a and 18b showed Ki values in the submicromolar range and relatively high selectivity toward CB2. Active compounds represent new scaffolds with such type of activity. Moreover, a multiple XED-based field templates model has been constructed for the activity interpretation of some of the synthesised compounds. The reported ligands can serve as a template to develop new CB2 ligands with enhanced potency and selectivity, and the computational model can be applied for SAR interpretation and/or structure optimization of any other CB2-selective ligand(s).
- Osman, Noha A.,Mahmoud, Amr H.,Klein, Christian D.,Allar, Marco,Di Marzo, Vincenzo,Abouzid, Khaled M.,Abadi, Ashraf H.
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supporting information
p. 1571 - 1576
(2014/12/10)
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- Silicon-directed rhenium-catalyzed allylic carbaminations and oxidative fragmentations of γ-silyl allylic alcohols
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A highly regioselective allylic substitution of β-silyl allylic alcohols has been achieved that provides the branched isomer as a single product. This high level of regiocontrol is achieved through the use of a vinyl silane group that can perform a Hiyama coupling providing 1,3-disubstituted allylic amines. An unusual oxidative fragmentation product was also observed at elevated temperature that appears to proceed by a Fleming-Tamao-type oxidation-elimination pathway.
- Chavhan, Sanjay W.,Cook, Matthew J.
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supporting information
p. 4891 - 4895
(2014/05/06)
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- Titanium-catalyzed intermolecular hydroaminoalkylation of conjugated dienes
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Ti me kangaroo down: Conjugated dienes undergo intermolecular hydroaminoalkylation in the presence of Ti catalyst [Ind2TiMe 2] (Ind=η5-indenyl). This new reaction offers a highly atom-efficient approach to homoallylic amines from 1,3-butadienes. Copyright
- Preuss, Till,Saak, Wolfgang,Doye, Sven
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p. 3833 - 3837
(2013/04/24)
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- Multistep organocatalysis for the asymmetric synthesis of multisubstituted aldehydes from allylic alcohols
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The combination of a copper complex and a chiral amine organocatalyst induces the formation of multifunctionalized aldehydes from aromatic and aliphatic allylic alcohols. Reactions occur with excellent levels of enantioselectivity, under environmentally benign conditions, and without involving stoichiometric amounts of chemical oxidants for the oxidation of the allylic alcohols or rigorous reaction conditions for transition-metal catalysis.
- Ho, Xuan-Huong,Oh, Hyun-Ji,Jang, Hye-Young
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p. 5655 - 5659
(2012/11/13)
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- Peroxyesters as precursors to peroxyl radical clocks
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The reactions of peroxyl radicals are at the center of the oxidative degradation of essentially all petroleum-derived hydrocarbons and biological lipids and consequently, the inhibition of these processes by radical-trapping antioxidants. Recently describ
- Hanthorn, Jason J.,Pratt, Derek A.
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scheme or table
p. 276 - 284
(2012/03/11)
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- A highly regio- and stereoselective cascade annulation of enals and benzodi(enone)s catalyzed by N-heterocyclic carbenes
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Three stereogenic centers in a row: The unconventional activation of enal compounds mediated by an N-heterocyclic carbene (NHC) has generated three consecutive reactive carbon centers that undergo highly regio- and stereoselective annulations with di(enone)s to generate benzotricyclic products containing multiple stereogenic centers (see scheme).
- Fang, Xinqiang,Jiang, Kun,Xing, Chong,Hao, Lin,Chi, Yonggui Robin
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supporting information; experimental part
p. 1910 - 1913
(2011/04/16)
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- Synthesis of functionalized cinnamaldehyde derivatives by an oxidative heck reaction and their use as starting materials for preparation of Mycobacterium tuberculosis 1-deoxy-d-xylulose-5-phosphate reductoisomerase inhibitors
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Cinnamaldehyde derivatives were synthesized in good to excellent yields in one step by a mild and selective, base-free palladium(II)-catalyzed oxidative Heck reaction starting from acrolein and various arylboronic acids. Prepared α,β-unsaturated aldehydes were used for synthesis of novel α-aryl substituted fosmidomycin analogues, which were evaluated for their inhibition of Mycobacterium tuberculosis 1-deoxy-d-xylulose 5-phosphate reductoisomerase. IC50 values between 0.8 and 27.3 μM were measured. The best compound showed activity comparable to that of the most potent previously reported α-aryl substituted fosmidomycin-class inhibitor.
- Nordqvist, Anneli,Bjoerkelid, Christofer,Andaloussi, Mounir,Jansson, Anna M.,Mowbray, Sherry L.,Karlen, Anders,Larhed, Mats
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experimental part
p. 8986 - 8998
(2011/12/03)
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- Iron-facilitated direct oxidative C-H transformation of allyl arenes to alkenyl aldehydes
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A direct oxidative approach to alkenyl aldehydes from allyl arenes via allyl sp3 C-H functionalization was disclosed. An inexpensive iron catalyst was employed to facilitate this transformation. The mechanistic studies indicate that the cleavage of the allyl sp3 C-H bond is involved in the rate-determining step.
- Wang, Teng,Xiang, Shi-Kai,Qin, Chong,Ma, Jun-An,Zhang, Li-He,Jiao, Ning
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supporting information; experimental part
p. 3208 - 3211
(2011/06/28)
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- Facile synthesis of (E)-alkenyl aldehydes from allyl arenes or alkenes via Pd(II)-catalyzed direct oxygenation of allylic C-H bond
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Palladium-catalyzed oxygenation of allyl arenes or alkenes has been developed to produce (E)-alkenyl aldehydes with high yields. Allylic C-H bond cleavages occur under the mild conditions during this process. Mechanistic studies show that oxygen source is water.(Figure Presented)
- Chen, Huoji,Jiang, Huanfeng,Cai, Congbi,Dong, Jia,Fu, Wei
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supporting information; experimental part
p. 992 - 994
(2011/05/08)
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- Iron(III) chloride-promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
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Aryl propargyl alcohols bearing a terminal alkynyl moiety can undergo a facile iron(III) chloride-promoted transformation to the corresponding α,β-unsaturated aldehyde in good yield and excellent stereoselectivity.
- El Douhaibi, Ahmad Samih,Judeh, Zaher M. A.,Basri, Hedaya,Moussa, Ziad,Messali, Mouslim,Qi, Gao
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experimental part
p. 533 - 540
(2011/04/22)
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- Dual-channel microreactor for gas-liquid syntheses
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A microreactor consisting of two microfluidic channels that are separated by a thin membrane is devised for intimate contact between gas and liquid phases. Gas flowing in one microchannel can diffuse into the liquid flowing in the other microchannel through the thin membrane. An oxidative Heck reaction carried out in the dual-channel (DC) microreactor, in which gaseous oxygen plays a key role in the catalytic reaction, shows the significant improvement that can be made over the traditional batch reactor and the conventional segmental microreactor in terms of yield, selectivity, and reaction time. It also allows independent control of the flow of the gaseous reagent. The proposed DC microreactor should prove to be a powerful tool for fully exploring gas-liquid microchemistry.
- Park, Chan Pil,Kim, Dong-Pyo
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supporting information; experimental part
p. 10102 - 10106
(2010/10/04)
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- Rare earth triflates/chlorotrimethylsilane induced activation of triethylamine as a latent acetaldehyde anion: a new synthesis of α,β-unsaturated aldehydes
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A synthetic methodology for α,β-unsaturated aldehydes employing rare earth triflate is reported. Activated triethylamine reacts with aldehydes to form two carbon extended aldehydes, which is promoted by a catalytic amount of Yb, Sc, Y, and In(OTf)3, in the presence of chlorotrimethylsilane. We investigated the conditions applicable to aromatic aldehydes as well as heterocyclic compounds as substrates. A deuterium labeling experiment supported our proposed reaction mechanism.
- Kagawa, Natsuko,Sasaki, Yoshiko,Kojima, Hideo,Toyota, Masahiro
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experimental part
p. 482 - 484
(2010/10/02)
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- Enantioselective methoxyselenenylation of a,β-unsaturated aldehydes
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In this communication we propose a convenient methodology to effect the asymmetric methoxyselenenylation of β-aryl α,β-unsaturated aldehydes using as electrophilic reagent an optically pure sulfur-containing selenenyl chloride. Mechanistic aspects of the
- Santi, Claudio,Santoro, Stefano,Tomassini, Cristina,Pascolini, Fabio,Testaferri, Lorenzo,Tiecco, Marcello
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body text
p. 743 - 746
(2009/08/07)
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- ANALGESIC 5, 9 - METHANOCYCLOOCTA (b) PYRIDIN - 2 (1H) - ONE DERIVATIVES, THEIR PREPARATION METHOD AND USE
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Compounds represented by the Formula I or salts, hydrates thereof, wherein R1, R8, R11 and R12 are H or C1-4 hydrocarbonyl respectively; R2, R3, R6 and R7 are H, halogen or C1-4 hydrocarbonyl respectively; R4 is C1-6 hydrocarbonyl or Ar; or =CR4R3 is cyclopentylidene, cyclohexylidene, 1-methylpiperidyl-4-idene or indenyl-1-idene; R5 is H, 1-4 same or different F, Cl, Br, CF3, R9, OR9, NR9R10, NO2, CN, COOR9, O2CR9, CONR9R10, NR9C(O)R10, heterocyclic, aryl or groups represented by the Formula II respectively; R9 and R10 are H or C1-6 hydrocarbonyl; Ar is aromatic ring; m is 0, 1 or 2; n is 0, 1, 2, 3 or 4, for treating mammal pain, functional painful syndrome, organic painful syndrome or tissue painful syndrome, and their preparation method.
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Page/Page column 15
(2009/04/23)
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- Microwave-assisted InCl3-catalyzed Meyer-Schuster rearrangement of propargylic aryl carbinols in aqueous media: a green approach to α,β-unsaturated carbonyl compounds
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A novel, efficient, simple and environmentally benign protocol for the Meyer-Schuster isomerization of propargylic aryl carbinols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of InCl3, pure water as the solvent, and microwave irradiation as the heating source.
- Cadierno, Victorio,Francos, Javier,Gimeno, José
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experimental part
p. 4773 - 4776
(2011/03/19)
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- Acrolein diethyl acetal: A three-carbon homologating reagent for the synthesis of β-arylpropanoates and cinnamaldehydes by heck reaction catalyzed by a Kaiser oxime resin derived palladacycle
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A polymer palladacycle derived from Kaiser oxime resin was used as a source of palladium(0) in the chemoselective Heck reaction of acrolein diethyl acetal with aryl halides under ligand-free conditions. The use of typical Heck conditions afforded 3-arylpropionic esters, and the process can be directed to the synthesis of cinnamaldehydes under Cacchi conditions. These processes take place with rather low loading of the catalyst, which can be recovered by simple filtration and reused for at least five runs without competitive dehalogenation. This is the first time that a supported palladium complex has been reused under Cacchi conditions. ICP-OES analyses of the Pd content of the crude products in both transformations indicated lower leaching for the esters than for the aldehydes in the range up to 0.08 ppm for the esters and 0.8 ppm for the aldehydes. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Alacid, Emilio,Najera, Carmen
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experimental part
p. 3102 - 3106
(2009/04/11)
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- Design and synthesis of a library of tertiary amides: Evaluation as mimetics of the melanocortins' active core
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Two hundred and ten tertiary amides were prepared on solid phase. Diamines were coupled to activated carboxylated Wang polymer, and the polymeric substituted benzyloxycarbonyl protected diamines obtained were reacted with aldehydes or ketones in trimethyl orthoformate giving resin attached Schiff bases. Coupled resins were then reduced to secondary amines by sodium cyanoborohydride in 4% acetic acid/trimethyl orthoformate, followed by acylation with the carboxylic acid in the presence of PyBroP and diisopropylethylamine. Cleavage of tertiary amides from the resin was made by trifluoroacetic acid in the presence of scavengers (mainly 1,2-ethanedithiol). When indole derivatives were prepared, parallel alkylation with the linker fragment occurred, giving derivatives of 2-(4-hydroxybenzyl)-indole as side products. Solution synthesis or mixed liquid/solid phase preparation of title substances proved to be advantageous in cases when the above method did not give acceptable results. According to this approach an efficient formation of Schiff bases was achieved in the presence of TiCl4. Substances were isolated by reversed phase chromatography; in some cases isomers were additionally separated by chiral chromatography on Chirobiotic T. When tested on human recombinant melanocortin receptors all the tertiary amides showed some binding affinities; for the highest affinity compounds the Kis reached 400 nM on MC1, 2 μM on MC3 and 1 μM on MC4 and MC5 receptors. cAMP assays of some of the title compounds showed that the tertiary amides are melanocortin receptor antagonists on the four MC receptor subtypes.
- Mutulis, Felikss,Kreicberga, Jana,Yahorava, Sviatlana,Mutule, Ilze,Borisova-Jan, Larisa,Yahorau, Aleh,Muceniece, Ruta,Azena, Sandra,Veiksina, Santa,Petrovska, Ramona,Wikberg, Jarl E.S.
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p. 5787 - 5810
(2008/09/18)
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- Transition metal-catalyzed synthesis of pyrroles from dienyl azides
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(Chemical Equation Presented) A range of 2,5-disubstituted and 2,4,5-trisubstituted pyrroles can be synthesized from dienyl azides at room temperature using catalytic amounts of Znl2 or Rh2(O 2CC3F7)4.
- Dong, Huijun,Shen, Meihua,Redford, Joanne E.,Stokes, Benjamin J.,Pumphrey, Ashley L.,Driver, Tom G.
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p. 5191 - 5194
(2008/09/17)
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- Efficient heterogeneously palladium-catalysed heck arylation of acrolein diethyl acetal. Selective synthesis of cinnamaldehydes or 3-arylpropionic esters
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A heterogeneous tetrakis(ammine)palladium-NaY zeolite {[Pd(NH 3)4]/NaY] catalyst was applied successfully to the Heck arylation of acrolein diethyl acetal using a large variety of aryl and heteroaryl bromides. Depending on the reaction conditions (Heck versus Cacchi) good to high selectivities toward the 3-arylpropionic esters or to the cinnamaldehydes were achieved, respectively. Under classical Heck conditions, while the catalyst was found to be stable over the two first runs, it showed significant loss of activity from the third cycle. Under Cacchi conditions, the catalyst could not be reused as it led to high dehalogenation rates. All results indicate that the reactions proceed through dissolved palladium species in the bulk solution (leaching). As observed by transmission electronic microscopic (TEM) analyses, while these species can be trapped and stabilised by the zeolite framework under the Heck conditions, they tend to form large palladium(0) aggregates under the Cacchi conditions leading to dehalogenation rather than to the expected Heck coupling.
- Noel, Sebastien,Luo, Ciahong,Pinel, Catherine,Djakovitch, Laurent
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p. 1128 - 1140
(2008/03/27)
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- Influence of the catalytic conditions on the selectivity of the Pd-catalyzed Heck arylation of acrolein derivatives
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The Heck arylation of acrolein with a variety of condensed aryl and heteroaryl halides is described. Depending on the substrate, up to 87% isolated yield to the expected aldehydes was achieved. When the reaction was run on diethylacetal acrolein, the choice of catalytic system dramatically affected the selectivity of the reaction: the catalyst system based on Herrmann's palladacycle complex gave mainly saturated esters 2, whereas Cacchi's conditions led to the formation of α,β-unsaturated aldehydes 1.
- No?l, Sébastien,Djakovitch, Laurent,Pinel, Catherine
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p. 3839 - 3842
(2007/10/03)
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- Tuning the oxidation properties of vanadium(V) through ligand stoichiometry
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Vanadium(V) (5 mol %) and hydroxamic acid ligand (45 mol %) were found to promote the selective tert-butyl hydroperoxide-mediated oxidation of allylic and propargylic alcohols to the corresponding aldehydes and ketones.
- Zeng, Wei,Ballard, T. Eric,Melander, Christian
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p. 5923 - 5926
(2007/10/03)
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- 1,2-Dioxines containing tethered hydroxyl functionality as convenient precursors for pyran syntheses
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A new method for the construction of tetrahydropyrans derived from readily available 1,2-dioxines containing a tethered hydroxyl moiety is described. The reaction proceeds via a base-catalyzed rearrangement of the 1,2-dioxines to either the isomeric cis or trans γ-hydroxy enones followed by intramolecular oxa-Michael addition of the tethered hydroxyl group.
- Avery, Thomas D.,Caiazza, Daniela,Culbert, Julie A.,Taylor, Dennis K.,Tiekink, Edward R. T.
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p. 8344 - 8351
(2007/10/03)
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- An efficient palladium-catalyzed synthesis of cinnamaldehydes from acrolein diethyl acetal and aryl iodides and bromides
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(Matrix presented) The reaction of aryl iodides and bromides with acrolein diethyl acetal in the presence of Pd(OAc)2, nBu 4NOAc, K2CO3, KCl, and DMF, at 90°C until the disappearance of the acetal followed by the addition of 2 N HCl to the crude reaction mixture, affords cinnamaldehydes in good to high yields. A variety of functional groups are tolerated in the aryl halides, including ether, aldehyde, ketone, ester, dialkylamino, nitrile, and nitro groups. The presence of substituents close to the oxidative addition site does not hamper the reaction.
- Battistuzzi, Gianfranco,Cacchi, Sandro,Fabrizi, Giancarlo
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p. 777 - 780
(2007/10/03)
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- Synthesis and antifungal activities of R-102557 and related dioxane- triazole derivatives
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Novel triazole compounds with a dioxane ring were synthesized. Condensation of the diol precursor 10 with various aromatic aldehydes 11 - 13 under acidic conditions afforded a series of dioxane-triazole compounds 14 - 16. The antifungal activities of the compounds 14 - 16 were evaluated in vivo in mice infection models against Candida and Aspergillus species. High activities were seen for the derivatives with one or two double bond(s) and an aromatic ring substituted with an electron-withdrawing group in the side chain. Among the derivatives, R-102557 (16R: Ar=4-(2,2,3,3- tetrafluoropropoxy)phenyl) showed excellent in vivo activities against Candida, Aspergillus and Cryptococcus species. It also showed high tolerance in a preliminary toxicity study in rats.
- Oida, Sadao,Tajima, Yawara,Konosu, Toshiyuki,Nakamura, Yoshie,Somada, Atsushi,Tanaka, Teruo,Habuki, Shinobu,Harasaki, Tamako,Kamai, Yasuki,Fukuoka, Takashi,Ohya, Satoshi,Yasuda, Hiroshi
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p. 694 - 707
(2007/10/03)
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- Phase transfer Wittig reaction with 1,3-dioxolan-2-yl-methyltriphenyl phosphonium salts: An efficient method for vinylogation of aromatic aldehydes
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Aldehydes were efficiently transformed into allylic dioxolanes by a Wittig-type reaction, using 1,3-dioxolan-2-yl-methyltriphenylphosphonium bromide under phase transfer conditions. The substituent kinetic effects were studied, and related to Hammett values and electrochemical potentials.
- Daubresse, Nicolas,Francesch, Charlette,Rolando, Christian
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p. 10761 - 10770
(2007/10/03)
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