Catalytic Asymmetric Synthesis of Both Enantiomers of 4‑Substituted 1,4-Dihydropyridines with the Use of Bifunctional Thiourea-Ammonium Salts Bearing Different Counterions
نویسندگان
چکیده
منابع مشابه
Catalytic asymmetric synthesis of both enantiomers of 4‑substituted 1,4-dihydropyridines with the use of bifunctional thiourea-ammonium salts bearing different counterions.
Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of ß-keto esters and α,ß-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and HBF(4) with the same bifunctional thiourea, both enantiomers of 4-substituted 1,4-dihydro...
متن کاملcomparison of catalytic activity of heteropoly compounds in the synthesis of bis(indolyl)alkanes.
heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...
15 صفحه اولthe use of appropriate madm model for ranking the vendors of mci equipments using fuzzy approach
abstract nowadays, the science of decision making has been paid to more attention due to the complexity of the problems of suppliers selection. as known, one of the efficient tools in economic and human resources development is the extension of communication networks in developing countries. so, the proper selection of suppliers of tc equipments is of concern very much. in this study, a ...
15 صفحه اولthe effect of task cognitive complexity and time limit on the performance of the learners with different proficiency levels in second language writing skill
this study investigated the effects of manipulating the cognitive complexity of tasks along +/- few elements and the time limits on l2 learners writing performance. to conduct the study, 60 iranian efl learners with two levels of proficiency, low and high intermediate, were selected and assigned to three groups based on the time devoted to task completion. the participants performed both a simp...
15 صفحه اولذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Molecules
سال: 2010
ISSN: 1420-3049
DOI: 10.3390/molecules15118305