Novel preparation of non-racemic 1-[α-(1-azacycloalkyl)benzyl]-2-naphthols from Betti base and their application as chiral ligands in the asymmetric addition of diethylzinc to aryl aldehydes
Redox-Neutral α-Oxygenation of Amines: Reaction Development and Elucidation of the Mechanism
作者:Matthew T. Richers、Martin Breugst、Alena Yu. Platonova、Anja Ullrich、Arne Dieckmann、K. N. Houk、Daniel Seidel
DOI:10.1021/ja501988b
日期:2014.4.23
secondary amines and 2-hydroxybenzaldehydes or related ketones react to furnish benzo[e][1,3]oxazine structures in generally good yields. This overall redox-neutral amine α-C–H functionalization features a combined reductive N-alkylation/oxidative α-functionalization and is catalyzed by acetic acid. In contrast to previous reports, no external oxidants or metal catalysts are required. Reactions performed
Diastereoselective α-C–H functionalization of aliphatic N-heterocycles: an efficient route to ring fused oxazines
作者:Sujit Mahato、Surajit Haldar、Chandan K. Jana
DOI:10.1039/c3cc46191b
日期:——
A novel method for direct CâH functionalization of saturated N-heterocycles allowing easy access to synthetically as well as biologically important and structurally diverse ring-fused oxazines is developed. The method is operationally simple and highly diastereoselective. Moreover, it is efficient in functionalizing broad classes of both cyclic and acyclic amines including the substrates that are otherwise difficult to functionalize.
Novel preparation of non-racemic 1-[α-(1-azacycloalkyl)benzyl]-2-naphthols from Betti base and their application as chiral ligands in the asymmetric addition of diethylzinc to aryl aldehydes
作者:Jun Lu、Xuenong Xu、Shaozhong Wang、Cunde Wang、Yuefei Hu、Hongwen Hu
DOI:10.1039/b204534f
日期:——
A novel route for the preparation of non-racemic 1-[α-(1-azacycloalkyl)benzyl]-2-naphthols was developed, which involves regioselective N-cycloalkylation of the Betti base with dials in the presence of NaBH3CN to give 1-azacycloalka[2,1-b]oxazine followed by the selective cleavage of a CâO bond with LiAlH4. As a new family of chiral ligands, their application in the enantioselective addition of diethylzinc to aryl aldehydes was tested. The ligands incorporating pyrrolidine and piperidine led to highly efficient asymmetric induction to give products in up to 96% yield and 99% ee.