A new simple,metal-free modification of mercapto-substituted silsesquioxane(SQ-SH)with α,β-unsaturated aldehydes is presented.Depending on the conditions used,the products of thioesterification or sulfa-Michael addi...A new simple,metal-free modification of mercapto-substituted silsesquioxane(SQ-SH)with α,β-unsaturated aldehydes is presented.Depending on the conditions used,the products of thioesterification or sulfa-Michael addition(SMA)are selectively obtained,following the green chemistry rules.For the first time,ball milling has been used in the solvent-free synthesis of sulfur-functionalized SQs.The proposed methodologies use commercially available reagents and lead to novel classes of SQ-based materials of great potential in industrial and synthetic applications.展开更多
2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,...2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.展开更多
基金financial support from the Ministry of Education and Science(project Diamond Grant No.DI2017002647)financial support from the National Science Centre(Poland)(SONATA 13,UMO-2017/26/D/ST5/00192)the Adam Mickiewicz University Foundation scholarship for the academic year 2022/2023.
文摘A new simple,metal-free modification of mercapto-substituted silsesquioxane(SQ-SH)with α,β-unsaturated aldehydes is presented.Depending on the conditions used,the products of thioesterification or sulfa-Michael addition(SMA)are selectively obtained,following the green chemistry rules.For the first time,ball milling has been used in the solvent-free synthesis of sulfur-functionalized SQs.The proposed methodologies use commercially available reagents and lead to novel classes of SQ-based materials of great potential in industrial and synthetic applications.
文摘2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.
