1360140-47-1Relevant academic research and scientific papers
Catalytic enantioselective desymmetrization of meso-glutaric anhydrides using a stable Ni2-schiff base catalyst
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
supporting information; experimental part, p. 1358 - 1361 (2012/04/23)
We describe the desymmetrization of meso-glutaric anhydrides to chiral hemiesters using a bench-stable homodinuclear Ni2-(Schiff base) complex as the catalyst in good to excellent yield (up to 99%) and enantioselectivity (up to 94%). Using the opposite enantiomer of the catalyst, we obtained the same yield and enantioselectivity with the opposite configuration, thereby gaining access to both hemiester enantiomers.
Studies on catalytic enantioselective total synthesis of caprazamycin B: Construction of the western zone
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
, p. 9260 - 9267,8 (2012/12/11)
We describe a simple and convenient synthesis of the western zone of caprazamycin B using two catalytic asymmetric reactions as key elements of our approach. Desymmetrization of 3-methylglutaric anhydride with the (S)-Ni 2-(Schiff base) complex as a catalyst furnished the chiral hemiester, and a thioamide-aldol reaction with mesitylcopper, (R,R)-Ph-BPE, and 2,2,5,7,8-pentamethylchromanol as a catalyst furnished the β-hydroxy thioamide in good yield and enantioselectivity. On further transformation, the thioamide functionality was converted to the corresponding β-hydroxy ester. Finally, a convergent synthesis of the western zone of caprazamycin B was achieved by connecting the hemiester, the β-hydroxy ester, and the 2,3,4-tri-O-methyl-l-rhamnose fragments.
Studies on catalytic enantioselective total synthesis of caprazamycin B: Construction of the western zone
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
, p. 9260 - 9267 (2013/01/15)
We describe a simple and convenient synthesis of the western zone of caprazamycin B using two catalytic asymmetric reactions as key elements of our approach. Desymmetrization of 3-methylglutaric anhydride with the (S)-Ni 2-(Schiff base) complex as a catalyst furnished the chiral hemiester, and a thioamide-aldol reaction with mesitylcopper, (R,R)-Ph-BPE, and 2,2,5,7,8-pentamethylchromanol as a catalyst furnished the β-hydroxy thioamide in good yield and enantioselectivity. On further transformation, the thioamide functionality was converted to the corresponding β-hydroxy ester. Finally, a convergent synthesis of the western zone of caprazamycin B was achieved by connecting the hemiester, the β-hydroxy ester, and the 2,3,4-tri-O-methyl-l-rhamnose fragments.
A chiral bifunctional sulfonamide as an organocatalyst: Alcoholysis of σ-symmetric cyclic dicarboxylic anhydrides
Honjo, Takashi,Tsumura, Takeshi,Sano, Shigeki,Nagao, Yoshimitsu,Yamaguchi, Kentaro,Sei, Yoshihisa
experimental part, p. 3279 - 3282 (2010/03/05)
Enantioselective alcoholysis of σ-symmetric cyclic dicarboxylic anhydrides with benzyl alcohol catalyzed by a chiral bifunctional sulfonamide was achieved in up to 98% ee at 5 mol% loading. Georg Thieme Verlag Stuttgart - New York.
