- Efficient Access to Chiral β-Borylated Carboxylic Esters via Rh-Catalyzed Hydrogenation
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Rh/bisphosphine?thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydrogenation of (Z)-β-substituted-β-boryl-α,β-unsaturated esters was successfully developed, furnishing a variety of chiral β-borylated carboxylic esters with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). The gram-scale asymmetric hydrogenation was performed efficiently in the presence of only 0.05 mol% (S/C=2 000) catalyst loading with full conversion, 99% yield and 99% ee. Moreover, the hydrogenation product was easily converted to other versatile synthetic intermediates, such as methyl (S)-3-hydroxy-3-phenylpropanoate and methyl (S)-3-(furan-2-yl)-3-phenylpropanoate. (Figure presented.).
- Liu, Gang,Li, Anqi,Qin, Xueyuan,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
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p. 2844 - 2848
(2019/04/26)
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- Synthesis of Chiral β-Borylated Carboxylic Esters via Nickel-Catalyzed Asymmetric Hydrogenation
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The highly efficient Ni-catalyzed asymmetric hydrogenation of β-boronic ester substituted-α,β-unsaturated carboxylic esters was successfully developed using (S,S)-Ph-BPE as the ligand. A series of chiral β-borylated carboxylic esters were obtained with high yields (94%-99% yields) and excellent enantioselectivities (89%-99% ee). The gram-scale asymmetric hydrogenation with a low catalyst loading (0.25 mol %) and synthetic transformation of hydrogenation product demonstrated the great synthetic utility of this methodology.
- Han, Zhengyu,Liu, Gang,Zhang, Xianghe,Li, Anqi,Dong, Xiu-Qin,Zhang, Xumu
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p. 3923 - 3926
(2019/06/14)
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- Palladium-Catalyzed Regio- and Stereoselective Sulfonylation of Aryl Propiolates with Sulfonyl Hydrazides: Access to (E)-β-Aryl Sulfonyl Acrylates
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An efficient method for the synthesis of (E)-β-aryl sulfonyl acrylates has been reported. This palladium-catalyzed approach showed excellent regio- and stereoselectivity in the sulfonylation of aryl propiolates with sulfonyl hydrazides. Through this approach, a wide range of (E)-β-aryl sulfonyl acrylates were obtained in moderate to high yields. (Figure presented.).
- Jiang, Huanfeng,Yan, Wuxin,Huang, Jiuzhong,Tan, Chaowei,Zhan, Lingzhi,Wu, Wanqing
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supporting information
p. 4575 - 4580
(2019/09/16)
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- Rh-Catalyzed Asymmetric Hydrogenation of β-Substituted-β-thio-α,β-unsaturated Esters: Expeditious Access to Chiral Organic Sulfides
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Rh/bifunctional bisphosphine-thiourea ligand (ZhaoPhos)-catalyzed asymmetric hydorgenation of both (Z)- and (E)-isomers of β-substituted-β-thio-α,β-unsaturated esters was successfully developed. This new asymmetric catalytic methodology provided highly efficient access to two enantiomers of chiral organic sulfides ethyl β-substituted-β-thio-propanoates with excellent results (up to 99% yield and >99% ee for (Z)-substrates, up to 99% yield and 98% ee for (E)-substrates, TON up to 5000), which are important intermediates in organic synthesis.
- Liu, Gang,Han, Zhengyu,Dong, Xiu-Qin,Zhang, Xumu
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p. 5636 - 5639
(2018/09/12)
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- Rhodium-catalyzed C(sp2)-H addition of arylboronic acids to alkynes using a boron-based, convertible ortho-directing group
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Temporary modification of a boronyl group with pyrazoryl-aniline allowed insertion of arylpropiolates and diphenylacet-ylenes into the o-C-H bond of arylboronic acids in the presence of rhodium catalysts, giving 3,3-diarylacrylates and triarylethene conta
- Yamamoto, Takeshi,Ishibashi, Aoi,Suginome, Michinori
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p. 1169 - 1172
(2017/08/07)
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- Structural design and synthesis of arylalkynyl amide-type peroxisome proliferator-activated receptor γ3 (PPAR γ3)-selective antagonists based on the helix12-folding inhibition hypothesis
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Peroxisome proliferator-activated receptor γ3 (PPARγ3) antagonists are candidates for treatment of type 2 diabetes, obesity and osteoporosis. However, few rational design strategies are currently available. Here, we utilized the helix12 (H12)-folding inhi
- Ohashi, Masao,Gamo, Kanae,Tanaka, Yuta,Waki, Minoru,Beniyama, Yoko,Matsuno, Kenji,Wada, Jun,Tenta, Masafumi,Eguchi, Jun,Makishima, Makoto,Matsuura, Nobuyasu,Oyama, Takuji,Miyachi, Hiroyuki
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- Minimizing Aryloxy Elimination in RhI-Catalyzed Asymmetric Hydrogenation of β-Aryloxyacrylic Acids using a Mixed-Ligand Strategy
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The first example of efficient asymmetric hydrogenation of challenging β-aryloxyacrylic acids was realized using a RhI-complex based on the heterocombination of a readily available chiral monodentate secondary phosphine oxide (SPO) and an achiral monodentate phosphine ligand as the catalyst. Excellent enantioselectivities (92->99% ee) were achieved for a wide variety of chiral β-aryloxypropionic acids with minor aryloxy elimination in most cases. The resultant products were readily transformed into biologically active compounds through simple synthetic manipulations.
- Li, Yang,Wang, Zheng,Ding, Kuiling
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supporting information
p. 16387 - 16390
(2015/11/09)
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- Copper(i)/phosphine-catalyzed tandem carboxylation/annulation of terminal alkynes under ambient pressure of CO2: One-pot access to 3a-hydroxyisoxazolo[3,2-a]isoindol-8(3aH)-ones
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An efficient method for the synthesis of 3a-hydroxyisoxazolo[3,2-a]isoindol-8(3aH)-ones from CO2, terminal alkynes, EtBr, and NHPI (N-hydroxyphthalimide) was developed through a tandem carboxylation/annulation strategy catalyzed by a copper(i)/phosphine system. This one-pot multicomponent reaction was conducted at atmospheric CO2 pressure to afford the target products in good to excellent yields under mild conditions. Notably, a wide range of functional groups were tolerated in this procedure. This protocol with simultaneous formation of four novel bonds i.e. two C-C bonds and two C-O bonds represents an efficient methodology for upgrading CO2 into heterocycles.
- Xie, Jia-Ning,Yu, Bing,Guo, Chun-Xiang,He, Liang-Nian
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p. 4061 - 4067
(2015/07/15)
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- A convenient regioselective synthesis of cyclopentadienones via palladium-catalyzed [2+2+1] cyclocarbonylation of alkynes
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A simple and efficient synthesis of cyclopentadienones via palladium-catalyzed cyclocarbonylation of alkynes under atmospheric pressure of carbon monoxide has been developed. The transformation was carried out under mild and ligand-free conditions, a wide range of substrates and exceptional functional group tolerance.
- Xu, Yanli,Zhao, Jinwu,Chen, Huoji,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 2488 - 2490
(2014/03/21)
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- Ruthenium-catalyzed [2+2] cycloaddition reactions of a 2-oxa-3- azabicyclo[2.2.1]hept-5-ene with unsymmetrical alkynes
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Ruthenium-catalyzed [2+2] cycloaddition reactions of a 2-oxa-3- azabicyclo[2.2.1]hept-5-ene with unsymmetrical alkynes were investigated. Yields of up to 90% were obtained though regioselectivity was modest. Select cycloadducts could be separated and used to access a highly functionalized [3.2.0] bicyclic structure through reductive cleavage of the N-O bond. These ring-opened products displayed a chemical exchange phenomenon in 1D carbon NMR and required characterization by 2D NMR techniques.
- Durham, Robin,Mandel, Jeremie,Blanchard, Nicolas,Tam, William
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scheme or table
p. 1494 - 1505
(2012/01/12)
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- Ligand-free copper(Ι)-catalyzed Sonogashira-type coupling of arylboronic acids with terminal alkynes
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An efficient ligand-free CuI-catalyzed Sonogashira-type coupling reaction of arylboronic acids with terminal alkynes under air is described. The electron-deficient alkynes gave the desired cross-coupling products in good yields. Thus, it represents a simple and alternative method for the traditional Sonogashira reaction.
- Pan, Changduo,Luo, Fang,Wang, Wenhui,Ye, Zhishi,Cheng, Jiang
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supporting information; scheme or table
p. 5044 - 5046
(2009/12/05)
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- TACHYKININ RECEPTOR ANTAGONISTS
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The present invention relates to selective NK-1 receptor antagonists of Formula (I) or a pharmaceutically acceptable salt thereof, for the treatment of disorders associated with an excess of tachykinins.
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