Dynamic kinetic asymmetric transfer hydrogenation of racemic 2,4-diaryl-2,3-dihydrobenzo[b][1,4]diazepines catalyzed by chiral phosphoric acids.
نویسندگان
چکیده
Dynamic kinetic Transfer hydrogenation reaction of 2-methyl-2,4-diaryl-2,3-dihydrobenzo[b][1,4]diazepines, using phosphoric acids as catalysts and Hantzsch ester as hydride source, has been studied. A 3,3'-H8-binol derived phosphoric acid has been identified the optimal chiral catalyst for this transformation, affording 1,3-diamine derivatives with up to 8/1 dr, 86% ee and 94% ee for the major and minor diastereomers, respectively.
منابع مشابه
Dynamic kinetic resolution in the stereoselective synthesis of 4,5-diaryl cyclic sulfamidates by using chiral rhodium-catalyzed asymmetric transfer hydrogenation.
The dynamic kinetic resolution of 4,5-diaryl cyclic sulfamidate imines was achieved via asymmetric transfer hydrogenation using a HCO(2)H/Et(3)N mixture as the hydrogen source and chiral Rh catalysts (R,R)- or (S,S)-RhCl(TsDPEN)Cp* affording the corresponding cyclic sulfamidates in good yields with up to >20 : 1 dr and up to >99% ee.
متن کاملChiral phosphoric acid-catalyzed oxidative kinetic resolution of indolines based on transfer hydrogenation to imines.
The oxidative kinetic resolution of 2-substituted indoline derivatives was achieved by hydrogen transfer to imines by means of a chiral phosphoric acid catalyst. The oxidative kinetic resolution was applicable to racemic alkyl- or aryl-substituted indolines, and the remaining indolines were obtained in good yields with excellent enantioselectivities.
متن کاملAsymmetric hydrogenation of α,α'-disubstituted cycloketones through dynamic kinetic resolution: an efficient construction of chiral diols with three contiguous stereocenters.
Chiral diols with three contiguous stereocenters were synthesized by a highly enantioselective ruthenium-catalyzed asymmetric hydrogenation of racemic α,α'-disubstituted cycloketones involving dynamic kinetic resolution. This new catalytic asymmetric method provides a concise route to the alkaloid (+)-γ-lycorane.
متن کاملHighly enantioselective hydrogenation of 2,4-diaryl-1,5-benzodiazepines catalyzed by dendritic phosphinooxazoline iridium complexes.
A PHOX with arms: A series of dendrimers with Ir phosphinooxazoline (PHOX) cores were designed and synthesized and found to be highly effective and recoverable catalysts for asymmetric hydrogenation of 2,4-diaryl-1,5-benzodiazepines. An obvious positive dendritic effect on reactivity was observed, leading to chiral nitrogen-containing heterocycles with excellent enantioselectivities.
متن کاملIridium-catalyzed asymmetric hydrogenation of racemic α-substituted lactones to chiral diols† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc04609f Click here for additional data file.
We report a protocol for the highly efficient iridium-catalyzed asymmetric hydrogenation of racemic a-substituted lactones via dynamic kinetic resolution. Using Ir-SpiroPAP (R)-1d as a catalyst, a wide range of chiral diols were prepared in a high yield (80–95%) with a high enantioselectivity (up to 95% ee) under mild reaction conditions. This protocol was used for enantioselective syntheses of...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Bioorganic & medicinal chemistry letters
دوره 19 14 شماره
صفحات -
تاریخ انتشار 2009