Novel chiral PN_4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis（o-formylphenyl）phenylphosphane and various chiral amino-sulfonamides.Their structures ...Novel chiral PN_4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis（o-formylphenyl）phenylphosphane and various chiral amino-sulfonamides.Their structures were fully characterized by IR,EI-MS and NMR.The catalytic systems,prepared in situ from the multidentate ligands and iridium（I） complexes,showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution,leading to corresponding optical alcohol with up to 75%ee.展开更多
Transition metal-catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral alcohols.Herein,a highly efficient and enantioselective transfer hydrogenation of dibe...Transition metal-catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral alcohols.Herein,a highly efficient and enantioselective transfer hydrogenation of dibenzoheptaheterocyclic ketones catalyzed by an arene-tethered TsDPEN-based Rh(ll)catalyst has been successfully developed,and a variety of dibenzoheptaheterocyclic ketones were reduced by a 1/1 mixture of formic acid and DBU(1,8-diazabicyclo[5.4.0]undec-7-ene)with high yields and enantioselectivities.With this method,the asymmetric reduction of 7,8-difluorodibenzo[b,e]thiepin-11(6H)-one has been realized,providing the key intermediate of baloxavir marboxil with>99% yield and>99% ee at a substrate/catalyst molar ratio of 1000.展开更多
The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aro...The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities（up to 99% conversion） and excellent enantioselectivities（up to 96% e.e.） under mild conditions. The chiral ruthenium（Ⅱ） complex （R,R）-3 has been prepared and characterized by NMR and X-ray crystallography.展开更多
The asymmetric reduction of carbonyl compounds by means of the Ru-chiral diphosphine-chiral diamine catalysts is widely useful in organic synthesis where high levels of enantioselectivities have been attributed to mul...The asymmetric reduction of carbonyl compounds by means of the Ru-chiral diphosphine-chiral diamine catalysts is widely useful in organic synthesis where high levels of enantioselectivities have been attributed to multiple ligand chiral elements as well as essential stereochemical matching synergies within them.Described here is the design and discovery of new pincer-type Ru-catalysts that feature only single stereogenic element within ligands,yet the such significantly simplified structure is demonstrated to be well competent for effecting asymmetric reductions as well as kinetic resolutions over a broad range of highly functionalized ketones/alcohols,including heteroaryl substituted substrates that were challenging by known catalyst systems.Alcohols were furnished not only in excellent enantioselectivities,but with turnover numbers(up to 100,000 TONs)that reach the highest levels known to date in asymmetric transfer hydrogenation of ketones.This work should help shed light on the intricate origin of enantioselection in these important processes,and further stimulate rational understanding as well as optimization of chiral catalysts towards efficiency and simplicity.展开更多
基金the National Natural Science Foundation of China(Nos20423002 and 20703034)Natural Science Foundation of Fujian Province of China(No2008J0235) for the financial support of this work
文摘Novel chiral PN_4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis（o-formylphenyl）phenylphosphane and various chiral amino-sulfonamides.Their structures were fully characterized by IR,EI-MS and NMR.The catalytic systems,prepared in situ from the multidentate ligands and iridium（I） complexes,showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution,leading to corresponding optical alcohol with up to 75%ee.
基金the Southern University of Science and Technology(start-up fund),Shenzhen Science and Technology Innovation Committee(No.KQTD20150717103157174)Stable Support Plan Program of Shenzhen Natural Science Fund(Program Contract No.20200925161222002)+4 种基金Key-Area Research and DevelopmentPt rogramofGuangdong Province((No.2020B010188001)Innovative Team of Universities in Guangdong Province(No.2020KCXTD016)National Natural Science Foundation of China(No.21991113)the National Natural Science Foundation of China(No.22171129)Shenzhen Science and Technology Innovation Committee(JCYJ20210324104202007)for financial support.
文摘Transition metal-catalyzed asymmetric transfer hydrogenation has been proven to be a powerful approach for the synthesis of chiral alcohols.Herein,a highly efficient and enantioselective transfer hydrogenation of dibenzoheptaheterocyclic ketones catalyzed by an arene-tethered TsDPEN-based Rh(ll)catalyst has been successfully developed,and a variety of dibenzoheptaheterocyclic ketones were reduced by a 1/1 mixture of formic acid and DBU(1,8-diazabicyclo[5.4.0]undec-7-ene)with high yields and enantioselectivities.With this method,the asymmetric reduction of 7,8-difluorodibenzo[b,e]thiepin-11(6H)-one has been realized,providing the key intermediate of baloxavir marboxil with>99% yield and>99% ee at a substrate/catalyst molar ratio of 1000.
基金Supported by the National Natural Science Foundation of China(Nos.2042300220703034)+1 种基金the Natural Science Foundation of Fujian Province of China(No.2008J0235)the Natural Science Foundation of Guangxi Province of China(No. 0991016)
文摘The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities（up to 99% conversion） and excellent enantioselectivities（up to 96% e.e.） under mild conditions. The chiral ruthenium（Ⅱ） complex （R,R）-3 has been prepared and characterized by NMR and X-ray crystallography.
基金supported by Shenzhen Nobel Prize Scientists Laboratory Project(C17783101)Shenzhen YOUWEI Tech Group,Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)+2 种基金the Natural Science Foundation of Guangdong Province(2021A1515010329)the National Natural Science Foundation of China(22171128)Shenzhen Science and Technology Program(KQTD20180411143514543,JCYJ20190809143611743)。
文摘The asymmetric reduction of carbonyl compounds by means of the Ru-chiral diphosphine-chiral diamine catalysts is widely useful in organic synthesis where high levels of enantioselectivities have been attributed to multiple ligand chiral elements as well as essential stereochemical matching synergies within them.Described here is the design and discovery of new pincer-type Ru-catalysts that feature only single stereogenic element within ligands,yet the such significantly simplified structure is demonstrated to be well competent for effecting asymmetric reductions as well as kinetic resolutions over a broad range of highly functionalized ketones/alcohols,including heteroaryl substituted substrates that were challenging by known catalyst systems.Alcohols were furnished not only in excellent enantioselectivities,but with turnover numbers(up to 100,000 TONs)that reach the highest levels known to date in asymmetric transfer hydrogenation of ketones.This work should help shed light on the intricate origin of enantioselection in these important processes,and further stimulate rational understanding as well as optimization of chiral catalysts towards efficiency and simplicity.
