54012-23-6Relevant academic research and scientific papers
Multisubstituted pyrazole synthesis via [3?+?2] cycloaddition/rearrangement/N[sbnd]H insertion cascade reaction of α-diazoesters and ynones
Feng, Xiaoming,Liu, Xiaohua,Zeng, Zi,Zhao, Peng
supporting information, p. 132 - 135 (2020/12/21)
The cascade reactions of alkyl α-diazoesters and ynones using Al(OTf)3 as the catalyst are described. A series of 4-substituted pyrazoles were obtained via [3 + 2] cycloaddition, 1,5-ester shift, 1,3-H shift, and N[sbnd]H insertion process. Deuterium labelling experiments, kinetic studies and control experiments were carried out for the rationalization of the mechanism.
Enantioselective [3 + 2] annulation of 4-isothiocyanato pyrazolones and alkynyl ketones under organocatalysis
Wang, Wenyao,Wei, Shiqiang,Bao, Xiaoze,Nawaz, Shah,Qu, Jingping,Wang, Baomin
supporting information, p. 1145 - 1154 (2021/02/16)
An asymmetric [3 + 2] annulation reaction of 4-isothiocyanato pyrazolones with alkynyl ketones in the presence of an organic catalyst derived from a cinchona alkaloid under mild conditions is realized. This protocol provides unprecedented expeditious access to a wide range of optically active spiro[pyrroline-pyrazolones] with various electronic properties in high yields with good to excellent enantioselectivities.
Laccase-mediated Oxidations of Propargylic Alcohols. Application in the Deracemization of 1-arylprop-2-yn-1-ols in Combination with Alcohol Dehydrogenases
González-Granda, Sergio,Méndez-Sánchez, Daniel,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 520 - 527 (2019/11/16)
The catalytic system composed by the laccase from Trametes versicolor and the oxy-radical TEMPO has been successfully applied in the sustainable oxidation of fourteen propargylic alcohols. The corresponding propargylic ketones were obtained in most cases in quantitative conversions (87–>99 % yield), demonstrating the efficiency of the chemoenzymatic methodology in comparison with traditional chemical oxidants, which usually lead to problems associated with the formation of by-products. Also, the stereoselective reduction of propargylic ketones was studied using alcohol dehydrogenases such as the one from Ralstonia species overexpressed in E. coli or the commercially available evo-1.1.200, allowing the access to both alcohol enantiomers mostly with complete conversions and variable selectivities depending on the aromatic pattern substitution (97–>99 % ee). To demonstrate the compatibility of the laccase-mediated oxidation and the alcohol dehydrogenase-catalyzed bioreduction, a deracemization strategy starting from the racemic compounds was developed through a sequential one-pot two-step process, obtaining a selection of (S)- or (R)-1-arylprop-2-yn-1-ols with excellent yields (>98 %) and selectivities (>98 % ee) depending on the alcohol dehydrogenase employed.
Gem-Digold Acetylide Complexes for Catalytic Intermolecular [4 + 2] Cycloaddition: Having Two Gold Centers Is Better for Asymmetric Catalysis
Nanko, Masaki,Shibuya, Satoru,Inaba, Yuya,Ono, Soichiro,Ito, Shigekazu,Mikami, Koichi
supporting information, p. 7353 - 7357 (2018/10/15)
Gold(I)-catalyzed highly enantioselective intermolecular [4 + 2] cycloaddition is shown with ynones and cyclohexadiene. Various bicyclo[2.2.2]octadiene derivatives are produced in high yields (up to 99%) with good enantioselectivity (up to 96% ee). Key to the success is generation of the gem-digold terminal alkyne as a catalytic on-cycle species. As proof of the gem-digold catalysis, a positive nonlinear effect is clarified between the ee's of the ligand and the cycloadduct.
VINYLOGOUS THIOESTER COMPOUNDS AND METHODS OF USE
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Paragraph 0140-0141, (2017/06/21)
Provided herein are vinylogous thioester compounds and methods for using the compounds.
2,4,6-TRIALKOXYSTRYL ARYL SULFONES, SULFONAMIDES AND CARBOXAMIDES, AND METHODS OF PREPARATION AND USE
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Page/Page column 58; 59, (2017/02/28)
Compounds according to Formula (I) are provided and salts thereof, wherein R1, R2, R33, R4, R5, R6, R13, A, X and Y are as defined herein. Methods for preparing compounds of Form
Styrene as 4π-Component in Zn(II)-Catalyzed Intermolecular Diels-Alder/Ene Tandem Reaction
Zheng, Min,Wu, Feng,Chen, Kai,Zhu, Shifa
supporting information, p. 3554 - 3557 (2016/08/16)
A mild Zn-catalyzed intermolecular Diels-Alder/ene tandem reaction with styrene as a 4π-component is reported. A variety of dihydronaphthalene products could be prepared in moderate to good yields. Moreover, a combination of DFT calculations and experiments was performed to further understand the mechanism of this unique tandem reaction.
Acyl hydrazides as acyl donors for the synthesis of diaryl and aryl alkyl ketones
Akhbar, Ahmed R.,Chudasama, Vijay,Fitzmaurice, Richard J.,Powell, Lyn,Caddick, Stephen
supporting information, p. 743 - 746 (2014/01/06)
In this communication we describe a novel strategy for the formation of valuable diaryl and aryl alkyl ketones from acyl hydrazides. A wide variety of ketones are prepared and the mild reaction conditions allow for the use of a range of functionalities, especially in the synthesis of diaryl ketones.
Parallel synthesis of "Click" chalcones as antitubulin agents
Utsintong, Maleeruk,Massarotti, Alberto,Caldarelli, Antonio,Theeramunkong, Sewan
, p. 510 - 516 (2013/07/28)
It has been shown that some chalcones are able to inhibit tubulin polymerization, giving cytotoxicity and destruction of tumoral vasculature. A library of 180 novel chalcone analogs has been synthesized via click chemistry and screened for their cytotoxic
Diversity-oriented synthesis based on the dppp-catalyzed mixed double-michael reactions of electron-deficient acetylenes and β-amino alcohols
Fan, Yi Chiao,Kwon, Ohyun
scheme or table, p. 3802 - 3825 (2011/06/24)
In this study, we prepared oxizolidines through 1,3-bis(diphenylphosphino)- propane (DPPP)-catalyzed mixed double-Michael reactions of β-amino alcohols with electron-deficient acetylenes. These reactions are very suitable for the diversity-oriented parallel syntheses of oxizolidines because: (i) they are performed under mild metal-free conditions and (ii) the products are isolated without complicated work-up. To demonstrate the applicability of mixed double-Michael reactions for the preparation of five-membered-ring heterocycles, we prepared 60 distinct oxazolidines from five β-amino alcohols and 12 electron-deficient acetylenes. We synthesized 36 of these 60 oxazolidines in enantiomerically pure form from proteinogenic amino acid-derived β-amino alcohols.
