1234381-67-9Relevant academic research and scientific papers
Atropselective Synthesis of N,C-Bis(diphenylphosphanes) from Bridged 2-Arylindoles Based on Effective Point-to-Axial Asymmetric Inductions after an Unusual Dilithiation ⊥
B?uerle, Felix,Brückner, Reinhard
, p. 9970 - 9975 (2019)
An asymmetric methanolysis of glutaric anhydride and 6 ensuing steps gave veratrol-annulated dimethylcyclo-heptenone diastereomers with 99% ee; ring closures occurred by Friedel-Crafts acylations of carboxylic acids obtained by stereospecific hydrogenolyses of a pair of diastereomeric δ-lactones. The mentioned cycloheptenones and Ph-NH-NH2 underwent Fischer indole syntheses providing the tetracyclic indoles cis- and trans-14a, respectively. Double lithiations with BuLi and quenchings with ClPPh2 furnished the diphosphanes cis- and trans-15 with perfect (P)- and (M)-atropselectivity, respectively.
Catalytic enantioselective desymmetrization of meso-glutaric anhydrides using a stable Ni2-schiff base catalyst
Gopinath, Purushothaman,Watanabe, Takumi,Shibasaki, Masakatsu
, 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.
Synthesis of both enantiomers of hemiesters by enantioselective methanolysis of meso cyclic anhydrides catalyzed by α-amino acid-derived chiral thioureas
Manzano, Ruben,Andres, Jose M.,Muruzabal, Maria-Dolores,Pedrosa, Rafael
supporting information; experimental part, p. 5417 - 5420 (2010/09/07)
(Figure presented) Both ureas and thioureas derived from l- or d-valine act as bifunctional organocatalysts able to induce the enantioselective alcoholysis of mono-, bi-, and tricyclic meso anhydrides. The desymmetrization occurs in near quantitative yields and excellent enantiomeric ratios (up to >99:1) under low catalyst loading. Both enantiomers of the hemiesters can be directly obtained by changing the configuration of the catalyst.
