4036-30-0Relevant articles and documents
Optical Resolution of (+/-)-Phenylsuccinic Acid by Using (-)-Proline as Resolving Agent
Shiraiwa, Tadashi,Sado, Yujin,Fujii, Shigeru,Nakamura, Mitsuhiro,Kurokawa, Hidemoto
, p. 824 - 826 (1987)
A solution of equimolar mixture of (+/-)-phenylsuccinic acid ((+/-)-PSA) and (-)-proline ((-)-Pro) in ethanol or its suspension in 2-propanol selectively gave a salt composed of 1-molar amount of PSA and 2-molar amount of (-)-Pro.The salt purified gave (+)-PSA with an optical purity of about 100percent.A salt composed of equimolar amounts of PSA and (-)-Pro was obtained from the ethanolic mother liquor, and gave (-)-PSA with an optical purity of 98percent.
Palladium-Catalyzed Asymmetric Hydroesterification of α-Aryl Acrylic Acids to Chiral Substituted Succinates
Ji, Xiaolei,Shen, Chaoren,Tian, Xinxin,Dong, Kaiwu
supporting information, p. 8645 - 8649 (2021/10/25)
A palladium-catalyzed asymmetric hydroesterification of α-aryl acrylic acids with CO and alcohol was developed, preparing a variety of chiral α-substituted succinates in moderate yields with high ee values. The kinetic profile of the reaction progress revealed that the alkene substrate first underwent the hydroesterification followed by esterification with alcohol. The origin of the enantioselectivity was elucidated by density functional theory computation.
An enantioselective claisen rearrangement catalyzed by N-heterocyclic carbenes
Kaeobamrung, Juthanat,Mahatthananchai, Jessada,Zheng, Pinguan,Bode, Jeffrey W.
supporting information; experimental part, p. 8810 - 8812 (2010/08/21)
In the presence of a chiral azolium salt (10 mol %), enols and ynals undergo a highly enantioselective annulation reaction to form enantiomerically enriched dihydropyranones via an N-heterocyclic carbene catalyzed variant of the Claisen rearrangement. Unlike other azolium-catalyzed reactions, this process requires no added base to generate the putative NHC-catalyst, and our investigations demonstrate that the counterion of the azolium salt plays a key role in the formation of the catalytically active species. Detailed kinetic studies eliminate a potential 1,4-addition as the mechanistic pathway; the observed rate law and activation parameters are consistent with a Claisen rearrangement as the rate-limiting step. This catalytic system was applied to the synthesis of enantioenriched kojic acid derivatives, a reaction of demonstrated synthetic utility for which other methods for catalytic enantioselective Claisen rearrangements have not provided a satisfactory solution.