1311201-72-5Relevant academic research and scientific papers
Enantioselective synthesis of angularly substituted 1-azabicylic rings: Coupled dynamic kinetic epimerization and chirality transfer
Aron, Zachary D.,Ito, Tatsuya,May, Tricia L.,Overman, Larry E.,Wang, Jocelyn
, p. 9929 - 9948 (2013/10/22)
A new strategy for enantioselective synthesis of azacyclic molecules in which dynamic kinetic equilibration of diastereomeric iminium ions precedes a stereochemistry-determining sigmatropic rearrangement is reported. The method is illustrated by the synthesis, in high enantiomeric purity (generally 95-99% ee), of a variety of 1-azabicyclic molecules containing angular allyl or 3-substituted 2-propenyl side chains adjacent to nitrogen and up to three stereogenic centers. In these products, the size of the carbocyclic ring is varied widely (5-12 membered); however, useful yields are obtained in forming 1-azabicyclic products containing only fused pyrrolidine and piperidine rings. Chirality transfer from substituents at carbons 1 and 2 of the 3-butenylamine fragment of the starting material is investigated, with methyl and phenyl substituents at the allylic position shown to provide exquisite stereocontrol (generally 98-99% chirality transfer). An attractive feature of the method is the ability to carry out the key transformation in the absence of solvent. Illustrated also is the high yielding conversion of four such products to a new family of bicyclic β-amino acids of high enantiomeric purity.
A chiral bidentate sp2-N ligand, naph-diPIM: Application to CpRu-catalyzed asymmetric dehydrative C-, N-, and O-allylation
Miyata, Kengo,Kutsuna, Hironori,Kawakami, Sho,Kitamura, Masato
, p. 4649 - 4653 (2011/06/27)
A handy new ligand: The CpRu complex (Cp=cyclopentadienyl) of a new type of chiral bisamidine ligand with a naphtho[1,2-b:7,8-b]dipyrroloimidazole (Naph-diPIM) skeleton with a Bronsted acid efficiently catalyzes dehydrative intermolecular C-allylation with high enantio- and regioselectivity. The catalytic system also gives nearly enantiomerically pure cycloalkanes and N- and O-heterocycles with a substrate/catalyst ratios of up to 10 000.
