Zusammenfassung
Chiral attachments on 2-oxoimidazolidine-4(S)-carboxylate ligands for dirhodium(11) can provide differential diastereoselection in catalytic reactions of diazo compounds. The synthesis of these heterocyclic ligands from the readily available amino acid asparagine is reported. Reactions with diazoacetates offering intramolecular carbon-hydrogen insertion provide evaluative data that demonstrate ...
Zusammenfassung
Chiral attachments on 2-oxoimidazolidine-4(S)-carboxylate ligands for dirhodium(11) can provide differential diastereoselection in catalytic reactions of diazo compounds. The synthesis of these heterocyclic ligands from the readily available amino acid asparagine is reported. Reactions with diazoacetates offering intramolecular carbon-hydrogen insertion provide evaluative data that demonstrate differential diastereoselection. Surprisingly, placement of a carbonyl group within the chiral attachment remove, enantiocontrol from the catalyst, presumably because of intramolecular ylide formation.