Olefins are very easily accessible compounds which are both popular substrates in synthetic chemistry and good ligands in the organometallic complexes.This dual character makes olefins a rich source of chiral ligands ...Olefins are very easily accessible compounds which are both popular substrates in synthetic chemistry and good ligands in the organometallic complexes.This dual character makes olefins a rich source of chiral ligands and catalysts for asymmetric catalysis.Herein,we willbriefly summarize our studies on the development of chiral diene ligands for transition-metal catalyzed asymmetric reactions and chiral FLP catalysts for asymmetric metal-free hydrogenations and hydrosilylations.Several acyclic chiral diene ligands as well as P/olefin and S/olefin hybrid ligands were developed for Rh or Pd-catalyzed asymmetric reactions.With these ligands in hand,we further put forward a novel strategy for acquiring chiral FLP catalysts via the in situ hydroboration of chiral dienes with Piers'borane.These catalysts proved to be highly ffective for asymmetric metal-free hydrogenations and hydrosilylations of imines,ilyl enol ethers,ketones,and aromatic N-heterocycles.展开更多
A rhodium/diene catalyzed asymmetric allylic trifluoromethoxylation reaction is reported,which afforded chiral trifluoromethoxylated allylic compounds in 52%–97%yields with up to 97%enantiomeric excess.These are the ...A rhodium/diene catalyzed asymmetric allylic trifluoromethoxylation reaction is reported,which afforded chiral trifluoromethoxylated allylic compounds in 52%–97%yields with up to 97%enantiomeric excess.These are the first examples of asymmetric allylic trifluoromethoxylation.The reactions proceed via a dynamic kinetic process that allowed for the use of racemic allylic trichloroacetimidates as substrates.Density functional theory calculations showed that the formation of the C–OCF_(3)bond occurs via outer-sphere nucleophilic attack.Importantly,the presence of the allylic group in the products enabled them to be converted into a diverse array of optically active trifluoromethylated molecules that are otherwise difficult to access.展开更多
基金We are grateful for the financial support from the National Natural Science Foundation of China(21521002 and 21825108).
文摘Olefins are very easily accessible compounds which are both popular substrates in synthetic chemistry and good ligands in the organometallic complexes.This dual character makes olefins a rich source of chiral ligands and catalysts for asymmetric catalysis.Herein,we willbriefly summarize our studies on the development of chiral diene ligands for transition-metal catalyzed asymmetric reactions and chiral FLP catalysts for asymmetric metal-free hydrogenations and hydrosilylations.Several acyclic chiral diene ligands as well as P/olefin and S/olefin hybrid ligands were developed for Rh or Pd-catalyzed asymmetric reactions.With these ligands in hand,we further put forward a novel strategy for acquiring chiral FLP catalysts via the in situ hydroboration of chiral dienes with Piers'borane.These catalysts proved to be highly ffective for asymmetric metal-free hydrogenations and hydrosilylations of imines,ilyl enol ethers,ketones,and aromatic N-heterocycles.
基金supported by the National Key Research and Development Program of China(grant no.2021YFF0701700)the National Natural Science Foundation of China(grant nos.21925105,92156001,and 22101141)+1 种基金the Natural Science Foundation of Tianjin(grant no.18JCJQJC47000)the Haihe Laboratory of Sustainable Chemical Transformations,and the Fundamental Research Funds for the Central Universities.
文摘A rhodium/diene catalyzed asymmetric allylic trifluoromethoxylation reaction is reported,which afforded chiral trifluoromethoxylated allylic compounds in 52%–97%yields with up to 97%enantiomeric excess.These are the first examples of asymmetric allylic trifluoromethoxylation.The reactions proceed via a dynamic kinetic process that allowed for the use of racemic allylic trichloroacetimidates as substrates.Density functional theory calculations showed that the formation of the C–OCF_(3)bond occurs via outer-sphere nucleophilic attack.Importantly,the presence of the allylic group in the products enabled them to be converted into a diverse array of optically active trifluoromethylated molecules that are otherwise difficult to access.
