- Mechanistically Guided One Pot Synthesis of Phosphine-Phosphite and Its Implication in Asymmetric Hydrogenation
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Although hybrid bidentate ligands are known to yield highly enantioselective products in asymmetric hydrogenation (AH), synthesis of these ligands is an arduous process. Herein, a one pot, atom-economic synthesis of a hybrid phosphine-phosphite (L1) is reported. After understanding the reactivity difference between an O-nucleophile versus C-nucleophile, one pot synthesis of Senphos (L1) was achieved (72 %). When L1 was treated with [Rh], 31P NMR revealed bidentate coordination to Rh. Senphos, in the presence of rhodium, catalyzes the AH of Methyl-2-acetamido-3-phenylacrylate and discloses an unprecedented turn over frequency of 2289, along with excellent enantio-selectivity (92 %). The generality is demonstrated by hydrogenating an array of alkenes. The AH operates under mild conditions of 1–2 bar H2 pressure, at room temperature. The practical relevance of L1 is demonstrated by scaling-up the reaction to 1 g and by synthesizing DOPA, a drug widely employed for the treatment of Parkinson's disease. Computational insights indicate that the R isomer is preferred by 3.8 kcal/mol over the S isomer.
- Sen, Anirban,Kumar, Rohit,Pandey, Swechchha,Vipin Raj,Kumar, Pawan,Vanka, Kumar,Chikkali, Samir H.
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supporting information
(2022/01/11)
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- New compounds having skin whitening, antioxidant and PPAR activity, and medical use thereof
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PURPOSE: A novel compound with skin whitening, antioxidation, and PPAR activation effects, and a medical use thereof are provided to be used for a pharmaceutical composition or a cosmetic product. CONSTITUTION: A compound is denoted by chemical formula 1. A skin whitening composition contains the compound as an active ingredient. An antioxidative composition for preventing or treating oxidative diseases contains the compound of chemical formula 1 as an active ingredient. The oxidative diseases are selected among skin aging, pigmentation, wrinkling, psoriasis, or eczema. The composition prevents or treats diseases which are regulated by PPAR(peroxisome proliferator-activated receptor) activity. The PPAR includes PPAR alpha or PPAR gamma.
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Paragraph 0343; 0346; 0350
(2017/04/14)
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- NOVEL COMPOUND HAVING SKIN-WHITENING, ANTI-OXIDIZING AND PPAR ACTIVITIES AND MEDICAL USE THEREFOR
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Provided are a novel compound having skin-whitening, anti-oxidizing and PPAR activities and a medical use thereof, and the compound has skin-whitening activities for the suppression of tyrosinase, and accordingly, is useful for use in skin-whitening pharmaceutical composition or cosmetic products; has anti-oxidant activities, and accordingly, is useful for the prevention and treatment of skin-aging; and has PPAR activities, and in particular, PPARα and PPARγ activities, and accordingly, is useful for use in pharmaceutical compositions or health foods which are effective for the prevention and treatment of obesity, metabolic disease, or cardiovascular disease.
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Paragraph 0234; 0236; 0238
(2014/02/16)
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- Facile synthesis of 4-arylidene-5-imidazolinones as synthetic analogs of fluorescent protein chromophore
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A facile and effective synthesis for a wide variety of 4-arylidene-5- imidazolinone derivatives was developed. 4-Arylidene-5-oxazolinones were prepared by Erlenmeyer azlactone synthesis from N-acylglycines and arylaldehydes. The ring-opening reactions of the 4-arylidene-5-oxazolinones with primary amines afforded 2-acylamino-3-arylacrylamides in excellent yields. A new dehydrative cyclization of the 2-acylamino-3-arylacrylamides in pyridine under reflux furnished the corresponding 4-arylidene-5-imidazolinones in good yields.
- Lee, Cheng-Yu,Chen, Yun-Chung,Lin, Hao-Chun,Jhong, Yuandong,Chang, Chih-Wei,Tsai, Ching-Hua,Kao, Chai-Lin,Chien, Tun-Cheng
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supporting information; experimental part
p. 5898 - 5907
(2012/09/07)
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- SUBSTITUTED BETA-PHENYL-ALPHA-HYDROXY PROPANOIC ACID, SYNTHESIS METHOD AND USE THEREOF
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The present invention relates to a compound of the formula (I), wherein R1, R2 and R3 are each independently selected from H, OH, F, Cl, Br, methoxy and ethoxy; or alternatively, R1 and R2 together form -OCH2O-, R3 is selected from H, OH, methoxy, ethoxy and halogens; R4 is OH or acyloxy; R5 is cycloalkoxyl, amino and substituted amino, and when R5 is selected from amino, at least one of R1, R2 and R3 is not H. The present invention further relates to a process for synthesizing a compound of the formula (I), and use of the compound of the formula (I) in the manufacture of a medicament for the prevention or treatment of cardiovascular or cerebrovascular diseases.
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Page/Page column 8-9
(2009/02/10)
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- Enol tautomer of the acetate ester of 3-methoxy-4-hydroxyphenylpyruvic acid: Crystallographic and NMR spectroscopic evidence
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The para acetate ester azlactone of vanillin 2 was synthesized from vanillin 1 and hydrolyzed with sodium hydroxide. The yielded product 3 was investigated with X-ray crystallographic and nuclear magnetic resonance techniques. Compound 3 crystallized in t
- Haasbroek,Oliver,Carpy
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p. 193 - 196
(2007/10/03)
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- A Facile Preparation of 4-Arylidene-4,5dihydrooxazol-5-ones using Zeolite as a Cyclodehydrating Agent
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An efficient new method for the azlactonisation of acylamino acids using zeolite under mild conditions is described; the method is fairly general as well as providing high yields.
- Boruah, Anima,Baruah, Partha P.,Sandhu, Jagir S.
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p. 614 - 615
(2007/10/03)
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- A modified synthesis of (±)-β-aryllactic acids
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The synthesis of racemic forms of the reportedly active principle of Danshen, namely (±)-β-(3,4-dihydroxyphenyl)lactic acid [(±)3-(3,4-dihydroxyphenyl)-2-hydroxypropanoic acid] and its seven racemic derivatives is reported.
- Wong,Xu,Chang,Lee
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p. 793 - 797
(2007/10/02)
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- N-cinnamylcarbamic acid esters
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Amines of the formula SPC1 Wherein R1 is lower alkyl, lower alkoxy or amino, R2 is hydrogen or lower alkyl, R3 is hydrogen, lower alkyl, carboxyl or lower alkoxycarbonyl, R4 is hydrogen or lower alkyl, R5/
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