Weihua Yang

Bio: Weihua Yang is an academic researcher from Jiangsu Normal University. The author has contributed to research in topic(s): Aldehyde & Trifluoromethyl. The author has an hindex of 2, co-authored 5 publication(s) receiving 10 citation(s).

One‐pot Combinatorial Synthesis of Benzo[4,5]imidazo‐[1,2‐a]thiopyrano[3,4‐d]pyrimidin‐4(3H)‐one Derivatives

Abstract: A series of novel fused tetracyclic benzo[4,5]imidazo[1,2-a]thiopyrano[3,4-d]pyrimidin-4(3H)-one derivatives were synthesized via the reaction of aryl aldehyde, 2H-thiopyran-3,5(4H,6H)-dione, and 1H-benzo[d]imidazol-2-amine in glacial acetic acid. This protocol features mild reaction conditions, high yields and short reaction time.

Improved QSPR Study of Diamagnetic Susceptibilities for Organic Compounds Using Two Novel Molecular Connectivity Indexes

Abstract: For predicting the molar diamagnetic susceptibilities of organic compounds, a variable molecular connectivity indexmχ' and its converse index mχ'' based on adjacency matrix of molecular graphs and the variable atomic valence connectivity index δi' were proposed. The optimal values of parameters x, a, and y included in definition of δi', mχ' and mχ'' can be found by an optimization method. When x2.9, a1.10, and y0.36, a good five-parameter model for the molar diamagnetic susceptibilities can be constructed from 0χ', 1χ', 2χ', 1χ'' and 2χ'' by using the best subset regression analysis method. The correlation coefficient r, standard error s, and average absolute deviation of the multilinear regression (MLR) model are 0.9930, 4.96 cgs, and 3.74 cgs, respectively, for the 721 organic compounds (training set). The cross-validation by using the leave-one-out method demonstrates that the MLR model is highly reliable from the point of view of statistics. The average absolute deviation of predicted values of the molar diamagnetic susceptibility of another 360 organic compounds (test set) is 4.37 cgs for the MLR model. The results show that the current method is more effective than literature methods for estimating the molar diamagnetic susceptibility of an organic compound. The MLR method can provide an acceptable model for the prediction of the molar diamagnetic susceptibilities of organic compounds.

Solvent‐Free Synthesis of 2‐(Phenylamino)‐4‐(trifluoromethyl)‐1,6‐dihydropyrimidine Derivatives Catalyzed by Sulfamic Acid

Abstract: A series of 2-(phenylamino)-4-(trifluoromethyl)-1,6-dihydropyrimidine derivatives were synthesized efficienly via the reaction of aryl aldehyde, ethyl 4,4,4-trifluoro-3-oxobutanoate and 1-phenylguanidine carbonate catalyzed by sulfamic acid under solvent-free conditions. This protocol has the advantages of mild condition, high yields and environmentally benign procedure.

One-Pot Combinatorial Synthesis of Benzo[4,5]imidazo[1,2-a]thiopyrano[3,4-d]pyrimidin-4(3H)-one Derivatives.

Abstract: A series of novel fused tetracyclic benzo[4,5]imidazo[1,2-a]thiopyrano[3,4-d]pyrimidin-4(3H)-one derivatives were synthesized via the reaction of aryl aldehyde, 2H-thiopyran-3,5(4H,6H)-dione, and 1H-benzo[d]imidazol-2-amine in glacial acetic acid. This protocol features mild reaction conditions, high yields and short reaction time.

Solvent‐Free Synthesis of 2‐(Phenylamino)‐4‐(trifluoromethyl)‐1,6‐dihydropyrimidine Derivatives Catalyzed by Sulfamic Acid.

Abstract: A series of 2-(phenylamino)-4-(trifluoromethyl)-1,6-dihydropyrimidine derivatives were synthesized efficienly via the reaction of aryl aldehyde, ethyl 4,4,4-trifluoro-3-oxobutanoate and 1-phenylguanidine carbonate catalyzed by sulfamic acid under solvent-free conditions. This protocol has the advantages of mild condition, high yields and environmentally benign procedure.

Diversity Oriented Syntheses of Conventional Heterocycles by Smart Multi Component Reactions (MCRs) of the Last Decade

Abstract: A collection of smart multicomponent reactions (MCRs) with continuative post condensation cyclizations (PCCs) is presented to construct conventional three- to seven-membered heterocyclic compounds in diversity oriented syntheses (DOS). These will provide a high degree of applying economical and ecological advantages as well as of practicability. Water, ionic liquids, and solvent-less syntheses as well as use of various forms of energy as microwave and ultrasonic irradiation are examined and discussed.

Alum (KAl(SO4)2·12H2O) Catalyzed Multicomponent Transformation: Simple, Efficient, and Green Route to Synthesis of Functionalized Spiro[chromeno[2,3‐d]pyrimidine‐5,3′‐indoline]‐tetraones in Ionic Liquid Media

Abstract: The combination of isatin, barbituric acid, and cyclohexane-1,3-dione derivatives in the presence of alum (KAl(SO4)2·12H2O) as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3-d]pyrimidine-5,3′-indoline]-tetraones.

Quantitative Structure–Property Relations (QSPRs) for Predicting the Standard Absolute Entropy (S298 K°) of Gaseous Organic Compounds

Abstract: To predict the standard absolute entropies of gaseous organic compounds, the variable molecular connectivity index (mχ′) and Ring parameter (H), based on adjacency matrix of molecular graphs, varia...

α-Aminoazoles/azines: key reaction partners for multicomponent reactions

Abstract: Aromatic α-aminoazaheterocycles are the focus of significant investigations and exploration by researchers owing to their key role in diverse biological and physiological processes. The existence of their derivatives in numerous drugs and alkaloids is due to their heterocyclic nitrogenous nature. Therefore, the synthesis of a structurally diverse range of their derivatives through simple and convenient methods represents a vital field of synthetic organic chemistry. Multicomponent reactions (MCRs) provide a platform to introduce desirable structure diversity and complexity into a molecule in a single operation with a significant reduction in the use of harmful organic waste, and hence have attracted particular attention as an excellent tool to access these derivatives. This review covers the advances made from 2010 to the beginning of 2020 in terms of the utilization of α-aminoazaheterocycles as synthetic precursors in MCRs.

QSPR study of molar diamagnetic susceptibility of diverse organic compounds using multiple linear regression analysis

Abstract: The multiple linear regression (MLR) was used to build the linear quantitative structure-property relationship (QSPR) model for the prediction of the molar diamagnetic susceptibility (χm) for 140 diverse organic compounds using the three significant descriptors calculated from the molecular structures alone and selected by stepwise regression method. Stepwise regression was employed to develop a regression equation based on 100 training compounds, and predictive ability was tested on 40 compounds reserved for that purpose. The stability of the proposed model was validated using Leave-One-Out cross-validation and randomization test. Application of the developed model to a testing set of 40 organic compounds demonstrates that the new model is reliable with good predictive accuracy and simple formulation. By applying MLR method we can predict the test set (40 compounds) with Q 2 ext of 0.9894 and average root mean square error (RMSE) of 2.2550. The model applicability domain was always verified by the leverage approach in order to propose reliable predicted data. The prediction results are in good agreement with the experimental values.