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27 results on '"Wang, Xi-Cun"'

15. Tunable synthesis of furfurylamines or β-amino alcohols viaRu-catalyzed N–H functionalization using biomass-derived polyols

Author

Jia, Le, Wang, Xue, Gao, Xiaolong, Makha, Mohamed, Wang, Xi-Cun, and Li, Yuehui

Abstract

We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines or β-amino alcohols compounds using ruthenium catalysis. The reaction outcome is readily tuned by the simple addition of 4 ​Å molecular sieves (furfurylamines vs.β-amino alcohols) with high chemo-selectivity. The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols viaa retro-aldol process. A series of arylamines was successfully transformed into the desired products with moderate to good yields.

Published
2022
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21. Template Synthesis to Solve the Unreachable OrthoC–H Functionalization Reaction of Aryl Iodide

Author

Zhang, Bo-Sheng, Jia, Wan-Yuan, Wang, Yi-Ming, Oliveira, João C. A., Warratz, Svenja, Zhang, Ze-Qiang, Gou, Xue-Ya, Liang, Yong-Min, Wang, Xi-Cun, Quan, Zheng-Jun, and Ackermann, Lutz

Abstract

This report describes the use of a simple Pd/NBE catalytic system to achieve orthoC–H oxylation and phosphonylation and other functionalizations of aryl iodide through templated conversion reactions. Dimethylamine is introduced in the ortho-site of aryl iodide through C–H amination, and aryl dimethylamine is quickly converted to methyl quaternary ammonium salt precipitation. Methyl quaternary ammonium salt avoids Hofmann elimination in subsequent functionalization. This method solves various orthofunctionalization reactions of aryl iodide that have not been achieved for a long time in the field of Pd/NBE chemistry indirectly.

Published
2023
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24. PS–PEG–SO3H as an efficient catalyst for 3,4-dihydropyrimidones via Biginelli reaction

Author

Quan, Zheng-Jun, Da, Yu-Xia, Zhang, Zhang, and Wang, Xi-Cun

Subjects
*POLYSTYRENE, *POLYETHYLENE glycol, *SULFONIC acids, *CHEMICAL reactions, *CATALYSTS, *CATALYST supports, *POLYMERS, *PYRIMIDINES
Abstract

Abstract: Polymer bound sulfonic acid was prepared on polystyrene–poly(ethylene glycol) (PS–PEG) resin. The PS–PEG-bound sulfonic acid exhibited good catalytic activity in the Biginelli-type reaction for the synthesis of 3,4-dihydropyrimidinones with good yield and good recyclability (six times). This method presents a remarkable technique toward an efficient synthesis of 3,4-dihydropyrimidinones. [Copyright &y& Elsevier]

Published
2009
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25. N , N -Diisopropylethylamine-Mediated Electrochemical Reduction of Azobenzenes in Dichloromethane.

Author

Zhou H, Fan R, Yang J, Sun X, Liu X, and Wang XC

Abstract

We report a cathodic reduction-dominated electrochemical approach for the hydrogenation of azobenzenes in dichloromethane. With cheap and readily available N , N -diisopropylethylamine as a catalytic mediator, the reaction proceeded smoothly in a simple undivided cell under constant-current electrolysis. A series of azobenzenes were successfully reduced to the corresponding hydrazobenzenes in moderate to high yields at room temperature. Preliminarily mechanistic studies indicate that solvent dichloromethane acts as a hydrogen source. The use of a common solvent as a hydrogen source, no need for stoichiometric mediators or metallic reductants, and mild conditions make this work a more straightforward and sustainable protocol for hydrogenation of azobenzenes.

Published
2022
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26. AgSCF 3 /Na 2 S 2 O 8 -Promoted Trifluoromethylthiolation/Cyclization of o-Propargyl Arylazides/ o-Alkynyl Benzylazides: Synthesis of SCF 3 -Substituted Quinolines and Isoquinolines.

Author

Qiu YF, Niu YJ, Wei X, Cao BQ, Wang XC, and Quan ZJ

Abstract

A AgSCF 3 /Na 2 S 2 O 8 -promoted trifluoromethylthiolation/cascade cyclization of o-propargyl arylazides (or o-alkynyl benzylazides) triggered by a carbon-carbon triple bond is reported. This strategy provides the synthesis of valuable SCF 3 -substituted quinoline and isoquinoline systems via the construction of one C(sp 2 )-SCF 3 bond and one C-N bond within one process.

Published
2019
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27. Ethyl 6-methyl-3-(2-methyl-prop-1-en-yl)-2-oxo-4-phenyl-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate.

Author

Wang XC, Tang XH, Da YX, Zhang Z, and Quan ZJ

Abstract

In the mol-ecule of the title compound, C(18)H(22)N(2)O(3), the dihydro-pyrimidinone ring adopts an envelope conformation. The dihedral angle between the phenyl ring and the mean plane through the enamine fragment is 86.04 (7)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯O hydrogen bond. In the crystal, inter-molecular N-H⋯O hydrogen bonds link pairs of mol-ecules into centrosymmetric dimers.

Published
2011
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