446063-64-5Relevant academic research and scientific papers
Enantiodivergent synthesis of pyrrolo[2,1-α]isoquinolines based on diastereoselective parham cyclization and α-amidoalkylation reactions
González-Temprano, Inés,Osante, I?aki,Lete, Esther,Sotomayor, Nuria
, p. 3875 - 3885 (2007/10/03)
Enantiodivergent synthesis of C-10b-substituted pyrrolo[2,1-α ]isoquinolines starting from an enantiomerically pure N-phenethylnorborn-5-en-endo-2,3-dicarboxyimide 3a, with a 2-exo-hydroxy-10-bornylsulfinyl group as a chiral auxiliary, has been developed. The key transformations are derived from diastereoselective intramolecular cyclization of aryllithiums and α-amidoalkylation reactions, with the ethylidene bridge of the norbornene moiety dictating the stereochemical outcome in both types of reactions. Thus, the organolithium addition-intramolecular α-amidoalkylation sequence on imide 3a afforded stereoselectively the R configuration at C-12b, whereas the tandem Parham cyclization-intermolecular α-amidoalkylation reactions on the corresponding iodinated imide 3b occurred with complete control of stereoselectivity, leading to the epimer at C-12b. Subsequent reductive removal of the chiral auxiliary and retro-Diels-Alder reaction afforded (10bS)-and (10bR)-pyrroloisoquinolines 1 in high yields and optical purities (>99% ee).
Highly diastereoselective intramolecular α-amidoalkylation reactions of hydroxylactams derived from N-phenethylimides. Enantioselective synthesis of dihydropyrrolo[2,1-a] isoquinolones
González-Temprano, Inés,Sotomayor, Nuria,Lete, Esther
, p. 593 - 597 (2007/10/03)
α-Hydroxylactams, derived from organolithium addition to an enantiomerically pure N-phenethylnorborn-5-en-endo-2,3-dicarboxyimide with a 2-exo-hydroxy-10-bornylsulfinyl group as chiral auxiliary, undergo efficient and highly diastereoselective N-acylimini
