A new type of chiral bisoxazoline ligands 1 based on spiro[4,4]-1,6-nonadiene backbone was easily prepared in six steps from racemic spiro[4,4]-nonane-1,6-dione,with the Pd-catalyzed coupling of the enol triflates wit...A new type of chiral bisoxazoline ligands 1 based on spiro[4,4]-1,6-nonadiene backbone was easily prepared in six steps from racemic spiro[4,4]-nonane-1,6-dione,with the Pd-catalyzed coupling of the enol triflates with CO and amino alcohols as the key steps for the construction of the oxazoline moiety. The structure of the ligand (R,S,S)-1b was unambiguously established by X-ray crystallographic analysis. The chiral Cu(II) complex generated in situ from the combination of spiro bisoxazoline ligand (S,S,S)-1c and Cu(OTf)2 was effective in the catalysis of asymmetric chlorination of the β-ketoester,methyl 1-oxo-2,3-dihydro-1H-indene-2-carboxylate,affording the corresponding chlorinated derivative in 99% yield with 17% ee.展开更多
The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ...The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced arenaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.展开更多
A class of chiral 1,3-bis(diarylphosphinoethyl)benzenes, which are key intermediates for the synthesis of PCP-type chiral pincer ligands, were prepared in high diastereomeric ratios and excellent ee values via double ...A class of chiral 1,3-bis(diarylphosphinoethyl)benzenes, which are key intermediates for the synthesis of PCP-type chiral pincer ligands, were prepared in high diastereomeric ratios and excellent ee values via double asymmetric hydrogenation of the corresponding bis(diarylvinylphosphine oxide) substrates using a SpinPhox/Ir(I) complex as the catalyst. The hydrogenation product 5a was readily transformed into the corresponding borane-protected chiral PCP-type pincer ligand 7a with high enantiomeric excess, exemplifying a viable synthetic route to optically active chiral PCP pincer ligands.展开更多
基金supported by the National Natural Science Foundation of China (20821002 and 20972176)the Chinese Academy of Sciences, the National Basic Research Program of China (2010CB833300),the Science and Technology Commission of Shanghai Municipality,and Merck Research Laboratories
文摘A new type of chiral bisoxazoline ligands 1 based on spiro[4,4]-1,6-nonadiene backbone was easily prepared in six steps from racemic spiro[4,4]-nonane-1,6-dione,with the Pd-catalyzed coupling of the enol triflates with CO and amino alcohols as the key steps for the construction of the oxazoline moiety. The structure of the ligand (R,S,S)-1b was unambiguously established by X-ray crystallographic analysis. The chiral Cu(II) complex generated in situ from the combination of spiro bisoxazoline ligand (S,S,S)-1c and Cu(OTf)2 was effective in the catalysis of asymmetric chlorination of the β-ketoester,methyl 1-oxo-2,3-dihydro-1H-indene-2-carboxylate,affording the corresponding chlorinated derivative in 99% yield with 17% ee.
基金supported by the National Natural Science Foundation of China(Grant Nos.20225204,20121202,20l320l0 and 20372071)the Chinese Academy of Sciences.the Maior Basic Research Development Program of China(Grant No.G2000077506)the Science and Technology Commission of Shang-hai M unicipality
文摘The history for the development of chiral phos- phorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent ad- vances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced arenaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.
基金supported by the Basic Research Development Program of China(2010CB833300)the National Natural Science Foundation of China(21121062,21232009)+1 种基金the Chinese Academy of Sciencesthe Science and Technology Commission of Shanghai Municipality
文摘A class of chiral 1,3-bis(diarylphosphinoethyl)benzenes, which are key intermediates for the synthesis of PCP-type chiral pincer ligands, were prepared in high diastereomeric ratios and excellent ee values via double asymmetric hydrogenation of the corresponding bis(diarylvinylphosphine oxide) substrates using a SpinPhox/Ir(I) complex as the catalyst. The hydrogenation product 5a was readily transformed into the corresponding borane-protected chiral PCP-type pincer ligand 7a with high enantiomeric excess, exemplifying a viable synthetic route to optically active chiral PCP pincer ligands.
