Simple inorganic base cesium hydroxide is found to be the best catalyst for aerobic annulation reaction of o-phenylenediamine andα-hydroxy-2-phenylacetophenone in constructing the quinoxaline skeleton,i.e.,catalytic ...Simple inorganic base cesium hydroxide is found to be the best catalyst for aerobic annulation reaction of o-phenylenediamine andα-hydroxy-2-phenylacetophenone in constructing the quinoxaline skeleton,i.e.,catalytic amount of cesium hydroxide can catalyze the reaction efficiently under mild conditions of room temperature in air atmosphere.This method is extendable to a series of vicinal diamines andα-hydroxyl ketones,thus having a relatively broad substrate scope.As no transition metal catalyst is required and cesium hydroxide highly water-soluble,cesiume can be effectively removed by washing with water,the prodcuts can be obtained without cesium and transition metal residue contamination.This reaction requires no other stoichiometric oxidants but the readily available and convenient air as the oxidant,and the only byproduct is water,hence a transition metal-free,mild and efficient,green and practical approach for efficient construction of the quinoxaline derivatives is provided.展开更多
In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive （Z）-1,2-diorganothio-1-alkene in exc...In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive （Z）-1,2-diorganothio-1-alkene in excellent yields. It could provide a new and expedient way for the preparation of symmetrical and unsymmetrical （Z）-1,2-diorganolthiol-1-alkenes.展开更多
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene ...In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.展开更多
In the presence of a catalytic amount of cesium hydroxide, the corresponding S-aryl phosphorothioates can he obtained by the reactions of dialkyl phosphites with diaryldisulfides in excellent yields at room temperatur...In the presence of a catalytic amount of cesium hydroxide, the corresponding S-aryl phosphorothioates can he obtained by the reactions of dialkyl phosphites with diaryldisulfides in excellent yields at room temperature, using DMSO as a solvent. The reaction mechanism was discussed. The method provides a new and expedient path for the preparation of $-aryl phosphorothioates.展开更多
The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reactio...The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography.展开更多
p-Quinols are ubiquitous structural motifs of various natural products and pharmaceutical compounds,and versatile building blocks in synthetic chemistry.The reported methods for the synthesis of p-quinol require stoic...p-Quinols are ubiquitous structural motifs of various natural products and pharmaceutical compounds,and versatile building blocks in synthetic chemistry.The reported methods for the synthesis of p-quinol require stoichiometric amounts of oxidants.Molecular oxygen is considered as an ideal oxidant due to its natural,inexpensive,and environmentally friendly characteristics.During the ongoing research of C–H bond hydroxylation,we found that multi-alkyl phenols could react with molecular oxygen under mild conditions.Herein,we describe an efficient oxidative de-aromatization of multi-alkyl phenols to p-quinols.1 atm of molecular oxygen was used as the oxidant.Many multi-alkyl phenols could react smoothly at room temperature.Isotopic labeling experiment was also performed,and the result proved that the oxygen atom in the produced hydroxyl group is from molecular oxygen.展开更多
文摘Simple inorganic base cesium hydroxide is found to be the best catalyst for aerobic annulation reaction of o-phenylenediamine andα-hydroxy-2-phenylacetophenone in constructing the quinoxaline skeleton,i.e.,catalytic amount of cesium hydroxide can catalyze the reaction efficiently under mild conditions of room temperature in air atmosphere.This method is extendable to a series of vicinal diamines andα-hydroxyl ketones,thus having a relatively broad substrate scope.As no transition metal catalyst is required and cesium hydroxide highly water-soluble,cesiume can be effectively removed by washing with water,the prodcuts can be obtained without cesium and transition metal residue contamination.This reaction requires no other stoichiometric oxidants but the readily available and convenient air as the oxidant,and the only byproduct is water,hence a transition metal-free,mild and efficient,green and practical approach for efficient construction of the quinoxaline derivatives is provided.
基金Project supported by the National Natural Science Foundation of China （Nos. 21071152, 20372020）.
文摘In the presence of catalytic amount of cesium hydroxide, the hydrothiolation of alkynyl sulfides occurred at room temperature in DMF under nitrogen atmosphere to afford exclusive （Z）-1,2-diorganothio-1-alkene in excellent yields. It could provide a new and expedient way for the preparation of symmetrical and unsymmetrical （Z）-1,2-diorganolthiol-1-alkenes.
基金Natural Science Foundation of Hunan(No.2009NK3162)National Natural Science Foundation of China(No.21003040,20372020) for financial support
文摘In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.
基金supported by the National Nature Science Foundation of China (Nos. 21273068, 21172061, J1210040)
文摘In the presence of a catalytic amount of cesium hydroxide, the corresponding S-aryl phosphorothioates can he obtained by the reactions of dialkyl phosphites with diaryldisulfides in excellent yields at room temperature, using DMSO as a solvent. The reaction mechanism was discussed. The method provides a new and expedient path for the preparation of $-aryl phosphorothioates.
基金the National Natural Science Foundation of China (No.20372020) for financial support.
文摘The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography.
基金supported by the National Natural Science Foundation of China(21325206,21172006)the Key Laboratory of Oil and Gas Fine Chemicals(XJDX0908-2013-2)
文摘p-Quinols are ubiquitous structural motifs of various natural products and pharmaceutical compounds,and versatile building blocks in synthetic chemistry.The reported methods for the synthesis of p-quinol require stoichiometric amounts of oxidants.Molecular oxygen is considered as an ideal oxidant due to its natural,inexpensive,and environmentally friendly characteristics.During the ongoing research of C–H bond hydroxylation,we found that multi-alkyl phenols could react with molecular oxygen under mild conditions.Herein,we describe an efficient oxidative de-aromatization of multi-alkyl phenols to p-quinols.1 atm of molecular oxygen was used as the oxidant.Many multi-alkyl phenols could react smoothly at room temperature.Isotopic labeling experiment was also performed,and the result proved that the oxygen atom in the produced hydroxyl group is from molecular oxygen.
